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mod
Dependencies: ST_401_84MHZ mbed
Fork of MPU9250AHRS by
Revision 3:f1893b5610f7, committed 2016-09-16
- Comitter:
- nikitamere
- Date:
- Fri Sep 16 01:04:02 2016 +0000
- Parent:
- 2:4e59a37182df
- Commit message:
- Modified
Changed in this revision
--- a/MPU9250.h Tue Aug 05 01:37:23 2014 +0000 +++ b/MPU9250.h Fri Sep 16 01:04:02 2016 +0000 @@ -1,10 +1,10 @@ #ifndef MPU9250_H #define MPU9250_H - + #include "mbed.h" #include "math.h" - -// See also MPU-9250 Register Map and Descriptions, Revision 4.0, RM-MPU-9250A-00, Rev. 1.4, 9/9/2013 for registers not listed in + +// See also MPU-9250 Register Map and Descriptions, Revision 4.0, RM-MPU-9250A-00, Rev. 1.4, 9/9/2013 for registers not listed in // above document; the MPU9250 and MPU9150 are virtually identical but the latter has a different register map // //Magnetometer Registers @@ -26,8 +26,8 @@ #define AK8963_ASAY 0x11 // Fuse ROM y-axis sensitivity adjustment value #define AK8963_ASAZ 0x12 // Fuse ROM z-axis sensitivity adjustment value -#define SELF_TEST_X_GYRO 0x00 -#define SELF_TEST_Y_GYRO 0x01 +#define SELF_TEST_X_GYRO 0x00 +#define SELF_TEST_Y_GYRO 0x01 #define SELF_TEST_Z_GYRO 0x02 /*#define X_FINE_GAIN 0x03 // [7:0] fine gain @@ -41,7 +41,7 @@ #define ZA_OFFSET_L_TC 0x0B */ #define SELF_TEST_X_ACCEL 0x0D -#define SELF_TEST_Y_ACCEL 0x0E +#define SELF_TEST_Y_ACCEL 0x0E #define SELF_TEST_Z_ACCEL 0x0F #define SELF_TEST_A 0x10 @@ -57,15 +57,15 @@ #define GYRO_CONFIG 0x1B #define ACCEL_CONFIG 0x1C #define ACCEL_CONFIG2 0x1D -#define LP_ACCEL_ODR 0x1E -#define WOM_THR 0x1F +#define LP_ACCEL_ODR 0x1E +#define WOM_THR 0x1F #define MOT_DUR 0x20 // Duration counter threshold for motion interrupt generation, 1 kHz rate, LSB = 1 ms #define ZMOT_THR 0x21 // Zero-motion detection threshold bits [7:0] #define ZRMOT_DUR 0x22 // Duration counter threshold for zero motion interrupt generation, 16 Hz rate, LSB = 64 ms #define FIFO_EN 0x23 -#define I2C_MST_CTRL 0x24 +#define I2C_MST_CTRL 0x24 #define I2C_SLV0_ADDR 0x25 #define I2C_SLV0_REG 0x26 #define I2C_SLV0_CTRL 0x27 @@ -141,7 +141,7 @@ #define DMP_RW_PNT 0x6E // Set read/write pointer to a specific start address in specified DMP bank #define DMP_REG 0x6F // Register in DMP from which to read or to which to write #define DMP_REG_1 0x70 -#define DMP_REG_2 0x71 +#define DMP_REG_2 0x71 #define FIFO_COUNTH 0x72 #define FIFO_COUNTL 0x73 #define FIFO_R_W 0x74 @@ -153,7 +153,7 @@ #define ZA_OFFSET_H 0x7D #define ZA_OFFSET_L 0x7E -// Using the MSENSR-9250 breakout board, ADO is set to 0 +// Using the MSENSR-9250 breakout board, ADO is set to 0 // Seven-bit device address is 110100 for ADO = 0 and 110101 for ADO = 1 //mbed uses the eight-bit device address, so shift seven-bit addresses left by one! #define ADO 0 @@ -161,39 +161,39 @@ #define MPU9250_ADDRESS 0x69<<1 // Device address when ADO = 1 #else #define MPU9250_ADDRESS 0x68<<1 // Device address when ADO = 0 -#endif +#endif // Set initial input parameters enum Ascale { - AFS_2G = 0, - AFS_4G, - AFS_8G, - AFS_16G + AFS_2G = 0, + AFS_4G, + AFS_8G, + AFS_16G }; enum Gscale { - GFS_250DPS = 0, - GFS_500DPS, - GFS_1000DPS, - GFS_2000DPS + GFS_250DPS = 0, + GFS_500DPS, + GFS_1000DPS, + GFS_2000DPS }; enum Mscale { - MFS_14BITS = 0, // 0.6 mG per LSB - MFS_16BITS // 0.15 mG per LSB + MFS_14BITS = 0, // 0.6 mG per LSB + MFS_16BITS // 0.15 mG per LSB }; uint8_t Ascale = AFS_2G; // AFS_2G, AFS_4G, AFS_8G, AFS_16G uint8_t Gscale = GFS_250DPS; // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS uint8_t Mscale = MFS_16BITS; // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution -uint8_t Mmode = 0x06; // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR +uint8_t Mmode = 0x06; // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR float aRes, gRes, mRes; // scale resolutions per LSB for the sensors //Set up I2C, (SDA,SCL) I2C i2c(I2C_SDA, I2C_SCL); DigitalOut myled(LED1); - + // Pin definitions int intPin = 12; // These can be changed, 2 and 3 are the Arduinos ext int pins @@ -202,7 +202,7 @@ int16_t magCount[3]; // Stores the 16-bit signed magnetometer sensor output float magCalibration[3] = {0, 0, 0}, magbias[3] = {0, 0, 0}; // Factory mag calibration and mag bias float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer -float ax, ay, az, gx, gy, gz, mx, my, mz; // variables to hold latest sensor data values +float ax, ay, az, gx, gy, gz, mx, my, mz; // variables to hold latest sensor data values int16_t tempCount; // Stores the real internal chip temperature in degrees Celsius float temperature; float SelfTest[6]; @@ -216,7 +216,7 @@ float beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta float GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s) float zeta = sqrt(3.0f / 4.0f) * GyroMeasDrift; // compute zeta, the other free parameter in the Madgwick scheme usually set to a small or zero value -#define Kp 2.0f * 5.0f // these are the free parameters in the Mahony filter and fusion scheme, Kp for proportional feedback, Ki for integral +#define Kp 6.0f * 5.0f // these are the free parameters in the Mahony filter and fusion scheme, Kp for proportional feedback, Ki for integral #define Ki 0.0f float pitch, yaw, roll; @@ -225,316 +225,307 @@ float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion float eInt[3] = {0.0f, 0.0f, 0.0f}; // vector to hold integral error for Mahony method -class MPU9250 { - - protected: - - public: - //=================================================================================================================== +class MPU9250 +{ + +protected: + +public: + //=================================================================================================================== //====== Set of useful function to access acceleratio, gyroscope, and temperature data //=================================================================================================================== - void writeByte(uint8_t address, uint8_t subAddress, uint8_t data) -{ - char data_write[2]; - data_write[0] = subAddress; - data_write[1] = data; - i2c.write(address, data_write, 2, 0); -} - - char readByte(uint8_t address, uint8_t subAddress) -{ - char data[1]; // `data` will store the register data - char data_write[1]; - data_write[0] = subAddress; - i2c.write(address, data_write, 1, 1); // no stop - i2c.read(address, data, 1, 0); - return data[0]; -} + void writeByte(uint8_t address, uint8_t subAddress, uint8_t data) { + char data_write[2]; + data_write[0] = subAddress; + data_write[1] = data; + i2c.write(address, data_write, 2, 0); + } - void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest) -{ - char data[14]; - char data_write[1]; - data_write[0] = subAddress; - i2c.write(address, data_write, 1, 1); // no stop - i2c.read(address, data, count, 0); - for(int ii = 0; ii < count; ii++) { - dest[ii] = data[ii]; + char readByte(uint8_t address, uint8_t subAddress) { + char data[1]; // `data` will store the register data + char data_write[1]; + data_write[0] = subAddress; + i2c.write(address, data_write, 1, 1); // no stop + i2c.read(address, data, 1, 0); + return data[0]; } -} - -void getMres() { - switch (Mscale) - { - // Possible magnetometer scales (and their register bit settings) are: - // 14 bit resolution (0) and 16 bit resolution (1) - case MFS_14BITS: - mRes = 10.0*4219.0/8190.0; // Proper scale to return milliGauss - break; - case MFS_16BITS: - mRes = 10.0*4219.0/32760.0; // Proper scale to return milliGauss - break; - } -} + void readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest) { + char data[14]; + char data_write[1]; + data_write[0] = subAddress; + i2c.write(address, data_write, 1, 1); // no stop + i2c.read(address, data, count, 0); + for(int ii = 0; ii < count; ii++) { + dest[ii] = data[ii]; + } + } -void getGres() { - switch (Gscale) - { - // Possible gyro scales (and their register bit settings) are: - // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11). - // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value: - case GFS_250DPS: - gRes = 250.0/32768.0; - break; - case GFS_500DPS: - gRes = 500.0/32768.0; - break; - case GFS_1000DPS: - gRes = 1000.0/32768.0; - break; - case GFS_2000DPS: - gRes = 2000.0/32768.0; - break; - } -} + void getMres() { + switch (Mscale) { + // Possible magnetometer scales (and their register bit settings) are: + // 14 bit resolution (0) and 16 bit resolution (1) + case MFS_14BITS: + mRes = 10.0*4219.0/8190.0; // Proper scale to return milliGauss + break; + case MFS_16BITS: + mRes = 10.0*4219.0/32760.0; // Proper scale to return milliGauss + break; + } + } -void getAres() { - switch (Ascale) - { - // Possible accelerometer scales (and their register bit settings) are: - // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11). - // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value: - case AFS_2G: - aRes = 2.0/32768.0; - break; - case AFS_4G: - aRes = 4.0/32768.0; - break; - case AFS_8G: - aRes = 8.0/32768.0; - break; - case AFS_16G: - aRes = 16.0/32768.0; - break; - } -} + void getGres() { + switch (Gscale) { + // Possible gyro scales (and their register bit settings) are: + // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11). + // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value: + case GFS_250DPS: + gRes = 250.0/32768.0; + break; + case GFS_500DPS: + gRes = 500.0/32768.0; + break; + case GFS_1000DPS: + gRes = 1000.0/32768.0; + break; + case GFS_2000DPS: + gRes = 2000.0/32768.0; + break; + } + } + + + void getAres() { + switch (Ascale) { + // Possible accelerometer scales (and their register bit settings) are: + // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11). + // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value: + case AFS_2G: + aRes = 2.0/32768.0; + break; + case AFS_4G: + aRes = 4.0/32768.0; + break; + case AFS_8G: + aRes = 8.0/32768.0; + break; + case AFS_16G: + aRes = 16.0/32768.0; + break; + } + } -void readAccelData(int16_t * destination) -{ - uint8_t rawData[6]; // x/y/z accel register data stored here - readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array - destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value - destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; - destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; -} + void readAccelData(int16_t * destination) { + uint8_t rawData[6]; // x/y/z accel register data stored here + readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array + destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value + destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; + destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; + } -void readGyroData(int16_t * destination) -{ - uint8_t rawData[6]; // x/y/z gyro register data stored here - readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array - destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value - destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; - destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; -} + void readGyroData(int16_t * destination) { + uint8_t rawData[6]; // x/y/z gyro register data stored here + readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array + destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value + destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; + destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; + } -void readMagData(int16_t * destination) -{ - uint8_t rawData[7]; // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition - if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set - readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array - uint8_t c = rawData[6]; // End data read by reading ST2 register - if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data - destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]); // Turn the MSB and LSB into a signed 16-bit value - destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ; // Data stored as little Endian - destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ; - } - } -} + void readMagData(int16_t * destination) { + uint8_t rawData[7]; // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition + if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set + readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array + uint8_t c = rawData[6]; // End data read by reading ST2 register + if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data + destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]); // Turn the MSB and LSB into a signed 16-bit value + destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ; // Data stored as little Endian + destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ; + } + } + } -int16_t readTempData() -{ - uint8_t rawData[2]; // x/y/z gyro register data stored here - readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array - return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ; // Turn the MSB and LSB into a 16-bit value -} + int16_t readTempData() { + uint8_t rawData[2]; // x/y/z gyro register data stored here + readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array + return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ; // Turn the MSB and LSB into a 16-bit value + } -void resetMPU9250() { - // reset device - writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device - wait(0.1); - } - - void initAK8963(float * destination) -{ - // First extract the factory calibration for each magnetometer axis - uint8_t rawData[3]; // x/y/z gyro calibration data stored here - writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer - wait(0.01); - writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode - wait(0.01); - readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values - destination[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc. - destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f; - destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f; - writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer - wait(0.01); - // Configure the magnetometer for continuous read and highest resolution - // set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register, - // and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates - writeByte(AK8963_ADDRESS, AK8963_CNTL, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR - wait(0.01); -} + void resetMPU9250() { + // reset device + writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device + wait(0.1); + } + + void initAK8963(float * destination) { + // First extract the factory calibration for each magnetometer axis + uint8_t rawData[3]; // x/y/z gyro calibration data stored here + writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer + wait(0.01); + writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode + wait(0.01); + readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values + destination[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc. + destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f; + destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f; + writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer + wait(0.01); + // Configure the magnetometer for continuous read and highest resolution + // set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register, + // and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates + writeByte(AK8963_ADDRESS, AK8963_CNTL, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR + wait(0.01); + } -void initMPU9250() -{ - // Initialize MPU9250 device - // wake up device - writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors - wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt + void initMPU9250() { +// Initialize MPU9250 device +// wake up device + writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors + wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt + +// get stable time source + writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001 - // get stable time source - writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001 +// Configure Gyro and Accelerometer +// Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively; +// DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both +// Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate + writeByte(MPU9250_ADDRESS, CONFIG, 0x03); + +// Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV) + writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above - // Configure Gyro and Accelerometer - // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively; - // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both - // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate - writeByte(MPU9250_ADDRESS, CONFIG, 0x03); - - // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV) - writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above - - // Set gyroscope full scale range - // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3 - uint8_t c = readByte(MPU9250_ADDRESS, GYRO_CONFIG); - writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5] - writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3] - writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro - - // Set accelerometer configuration - c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG); - writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5] - writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3] - writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer +// Set gyroscope full scale range +// Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3 + uint8_t c = readByte(MPU9250_ADDRESS, GYRO_CONFIG); + writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5] + writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3] + writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro + +// Set accelerometer configuration + c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG); + writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5] + writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3] + writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer - // Set accelerometer sample rate configuration - // It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for - // accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz - c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2); - writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c & ~0x0F); // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0]) - writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c | 0x03); // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz +// Set accelerometer sample rate configuration +// It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for +// accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz + c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2); + writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c & ~0x0F); // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0]) + writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c | 0x03); // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz - // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates, - // but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting +// The accelerometer, gyro, and thermometer are set to 1 kHz sample rates, +// but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting - // Configure Interrupts and Bypass Enable - // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips - // can join the I2C bus and all can be controlled by the Arduino as master - writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22); - writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt -} + // Configure Interrupts and Bypass Enable + // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips + // can join the I2C bus and all can be controlled by the Arduino as master + writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22); + writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt + } // Function which accumulates gyro and accelerometer data after device initialization. It calculates the average // of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers. -void calibrateMPU9250(float * dest1, float * dest2) -{ - uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data - uint16_t ii, packet_count, fifo_count; - int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0}; - + void calibrateMPU9250(float * dest1, float * dest2) { + uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data + uint16_t ii, packet_count, fifo_count; + int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0}; + // reset device, reset all registers, clear gyro and accelerometer bias registers - writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device - wait(0.1); - + writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device + wait(0.1); + // get stable time source // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001 - writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); - writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00); - wait(0.2); - + writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); + writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00); + wait(0.2); + // Configure device for bias calculation - writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts - writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable FIFO - writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source - writeByte(MPU9250_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master - writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes - writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP - wait(0.015); - + writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts + writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable FIFO + writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source + writeByte(MPU9250_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master + writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes + writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP + wait(0.015); + // Configure MPU9250 gyro and accelerometer for bias calculation - writeByte(MPU9250_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz - writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz - writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity - writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity - - uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec - uint16_t accelsensitivity = 16384; // = 16384 LSB/g + writeByte(MPU9250_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz + writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz + writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity + writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity + + uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec + uint16_t accelsensitivity = 16384; // = 16384 LSB/g // Configure FIFO to capture accelerometer and gyro data for bias calculation - writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO - writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250) - wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes + writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO + writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250) + wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes // At end of sample accumulation, turn off FIFO sensor read - writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO - readBytes(MPU9250_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count - fifo_count = ((uint16_t)data[0] << 8) | data[1]; - packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging + writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO + readBytes(MPU9250_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count + fifo_count = ((uint16_t)data[0] << 8) | data[1]; + packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging + + for (ii = 0; ii < packet_count; ii++) { + int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0}; + readBytes(MPU9250_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging + accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO + accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ; + accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ; + gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ; + gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ; + gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ; + + accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases + accel_bias[1] += (int32_t) accel_temp[1]; + accel_bias[2] += (int32_t) accel_temp[2]; + gyro_bias[0] += (int32_t) gyro_temp[0]; + gyro_bias[1] += (int32_t) gyro_temp[1]; + gyro_bias[2] += (int32_t) gyro_temp[2]; - for (ii = 0; ii < packet_count; ii++) { - int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0}; - readBytes(MPU9250_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging - accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO - accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ; - accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ; - gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ; - gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ; - gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ; - - accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases - accel_bias[1] += (int32_t) accel_temp[1]; - accel_bias[2] += (int32_t) accel_temp[2]; - gyro_bias[0] += (int32_t) gyro_temp[0]; - gyro_bias[1] += (int32_t) gyro_temp[1]; - gyro_bias[2] += (int32_t) gyro_temp[2]; - -} - accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases - accel_bias[1] /= (int32_t) packet_count; - accel_bias[2] /= (int32_t) packet_count; - gyro_bias[0] /= (int32_t) packet_count; - gyro_bias[1] /= (int32_t) packet_count; - gyro_bias[2] /= (int32_t) packet_count; - - if(accel_bias[2] > 0L) {accel_bias[2] -= (int32_t) accelsensitivity;} // Remove gravity from the z-axis accelerometer bias calculation - else {accel_bias[2] += (int32_t) accelsensitivity;} - + } + accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases + accel_bias[1] /= (int32_t) packet_count; + accel_bias[2] /= (int32_t) packet_count; + gyro_bias[0] /= (int32_t) packet_count; + gyro_bias[1] /= (int32_t) packet_count; + gyro_bias[2] /= (int32_t) packet_count; + + if(accel_bias[2] > 0L) { + accel_bias[2] -= (int32_t) accelsensitivity; // Remove gravity from the z-axis accelerometer bias calculation + } else { + accel_bias[2] += (int32_t) accelsensitivity; + } + // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup - data[0] = (-gyro_bias[0]/4 >> 8) & 0xFF; // Divide by 4 to get 32.9 LSB per deg/s to conform to expected bias input format - data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases - data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF; - data[3] = (-gyro_bias[1]/4) & 0xFF; - data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF; - data[5] = (-gyro_bias[2]/4) & 0xFF; + data[0] = (-gyro_bias[0]/4 >> 8) & 0xFF; // Divide by 4 to get 32.9 LSB per deg/s to conform to expected bias input format + data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases + data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF; + data[3] = (-gyro_bias[1]/4) & 0xFF; + data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF; + data[5] = (-gyro_bias[2]/4) & 0xFF; /// Push gyro biases to hardware registers -/* writeByte(MPU9250_ADDRESS, XG_OFFSET_H, data[0]); - writeByte(MPU9250_ADDRESS, XG_OFFSET_L, data[1]); - writeByte(MPU9250_ADDRESS, YG_OFFSET_H, data[2]); - writeByte(MPU9250_ADDRESS, YG_OFFSET_L, data[3]); - writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]); - writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, data[5]); -*/ - dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction - dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity; - dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity; + /* writeByte(MPU9250_ADDRESS, XG_OFFSET_H, data[0]); + writeByte(MPU9250_ADDRESS, XG_OFFSET_L, data[1]); + writeByte(MPU9250_ADDRESS, YG_OFFSET_H, data[2]); + writeByte(MPU9250_ADDRESS, YG_OFFSET_L, data[3]); + writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]); + writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, data[5]); + */ + dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction + dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity; + dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity; // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold @@ -542,138 +533,137 @@ // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that // the accelerometer biases calculated above must be divided by 8. - int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases - readBytes(MPU9250_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values - accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1]; - readBytes(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]); - accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1]; - readBytes(MPU9250_ADDRESS, ZA_OFFSET_H, 2, &data[0]); - accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1]; - - uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers - uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis - - for(ii = 0; ii < 3; ii++) { - if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit - } + int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases + readBytes(MPU9250_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values + accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1]; + readBytes(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]); + accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1]; + readBytes(MPU9250_ADDRESS, ZA_OFFSET_H, 2, &data[0]); + accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1]; + + uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers + uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis + + for(ii = 0; ii < 3; ii++) { + if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit + } - // Construct total accelerometer bias, including calculated average accelerometer bias from above - accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale) - accel_bias_reg[1] -= (accel_bias[1]/8); - accel_bias_reg[2] -= (accel_bias[2]/8); - - data[0] = (accel_bias_reg[0] >> 8) & 0xFF; - data[1] = (accel_bias_reg[0]) & 0xFF; - data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers - data[2] = (accel_bias_reg[1] >> 8) & 0xFF; - data[3] = (accel_bias_reg[1]) & 0xFF; - data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers - data[4] = (accel_bias_reg[2] >> 8) & 0xFF; - data[5] = (accel_bias_reg[2]) & 0xFF; - data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers + // Construct total accelerometer bias, including calculated average accelerometer bias from above + accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale) + accel_bias_reg[1] -= (accel_bias[1]/8); + accel_bias_reg[2] -= (accel_bias[2]/8); + + data[0] = (accel_bias_reg[0] >> 8) & 0xFF; + data[1] = (accel_bias_reg[0]) & 0xFF; + data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers + data[2] = (accel_bias_reg[1] >> 8) & 0xFF; + data[3] = (accel_bias_reg[1]) & 0xFF; + data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers + data[4] = (accel_bias_reg[2] >> 8) & 0xFF; + data[5] = (accel_bias_reg[2]) & 0xFF; + data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers // Apparently this is not working for the acceleration biases in the MPU-9250 // Are we handling the temperature correction bit properly? // Push accelerometer biases to hardware registers -/* writeByte(MPU9250_ADDRESS, XA_OFFSET_H, data[0]); - writeByte(MPU9250_ADDRESS, XA_OFFSET_L, data[1]); - writeByte(MPU9250_ADDRESS, YA_OFFSET_H, data[2]); - writeByte(MPU9250_ADDRESS, YA_OFFSET_L, data[3]); - writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]); - writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, data[5]); -*/ + /* writeByte(MPU9250_ADDRESS, XA_OFFSET_H, data[0]); + writeByte(MPU9250_ADDRESS, XA_OFFSET_L, data[1]); + writeByte(MPU9250_ADDRESS, YA_OFFSET_H, data[2]); + writeByte(MPU9250_ADDRESS, YA_OFFSET_L, data[3]); + writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]); + writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, data[5]); + */ // Output scaled accelerometer biases for manual subtraction in the main program - dest2[0] = (float)accel_bias[0]/(float)accelsensitivity; - dest2[1] = (float)accel_bias[1]/(float)accelsensitivity; - dest2[2] = (float)accel_bias[2]/(float)accelsensitivity; -} + dest2[0] = (float)accel_bias[0]/(float)accelsensitivity; + dest2[1] = (float)accel_bias[1]/(float)accelsensitivity; + dest2[2] = (float)accel_bias[2]/(float)accelsensitivity; + } // Accelerometer and gyroscope self test; check calibration wrt factory settings -void MPU9250SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass -{ - uint8_t rawData[6] = {0, 0, 0, 0, 0, 0}; - uint8_t selfTest[6]; - int16_t gAvg[3], aAvg[3], aSTAvg[3], gSTAvg[3]; - float factoryTrim[6]; - uint8_t FS = 0; - - writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz - writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz - writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps - writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz - writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g + void MPU9250SelfTest(float * destination) { // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass + uint8_t rawData[6] = {0, 0, 0, 0, 0, 0}; + uint8_t selfTest[6]; + int16_t gAvg[3], aAvg[3], aSTAvg[3], gSTAvg[3]; + float factoryTrim[6]; + uint8_t FS = 0; + + writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz + writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz + writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps + writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz + writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g + + for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer - for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer - - readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array - aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value - aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; - aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; - - readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array - gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value - gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; - gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; - } - - for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average current readings - aAvg[ii] /= 200; - gAvg[ii] /= 200; - } - + readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array + aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value + aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; + aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; + + readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array + gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value + gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; + gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; + } + + for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average current readings + aAvg[ii] /= 200; + gAvg[ii] /= 200; + } + // Configure the accelerometer for self-test - writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g - writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s - delay(25); // Delay a while to let the device stabilize + writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g + writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s + wait(0.25); // Delay a while to let the device stabilize + + for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer - for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer - - readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array - aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value - aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; - aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; - - readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array - gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value - gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; - gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; - } - - for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average self-test readings - aSTAvg[ii] /= 200; - gSTAvg[ii] /= 200; - } - - // Configure the gyro and accelerometer for normal operation - writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); - writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); - delay(25); // Delay a while to let the device stabilize - - // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg - selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results - selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results - selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results - selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results - selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results - selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results + readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array + aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value + aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; + aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; + + readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array + gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value + gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; + gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ; + } + + for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average self-test readings + aSTAvg[ii] /= 200; + gSTAvg[ii] /= 200; + } + +// Configure the gyro and accelerometer for normal operation + writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); + writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); + wait(0.25); // Delay a while to let the device stabilize - // Retrieve factory self-test value from self-test code reads - factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation - factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation - factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation - factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation - factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation - factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation - - // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response - // To get percent, must multiply by 100 - for (int i = 0; i < 3; i++) { - destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i]; // Report percent differences - destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3]; // Report percent differences - } - -} + // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg + selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results + selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results + selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results + selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results + selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results + selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results + + // Retrieve factory self-test value from self-test code reads + factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation + factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation + factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation + factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation + factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation + factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation + +// Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response +// To get percent, must multiply by 100 + for (int i = 0; i < 3; i++) { + destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i]; // Report percent differences + destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3]; // Report percent differences + } + + } @@ -683,192 +673,375 @@ // device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc. // The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms // but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz! - void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz) - { - float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability - float norm; - float hx, hy, _2bx, _2bz; - float s1, s2, s3, s4; - float qDot1, qDot2, qDot3, qDot4; + void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz) { + float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability + float norm; + float hx, hy, _2bx, _2bz; + float s1, s2, s3, s4; + float qDot1, qDot2, qDot3, qDot4; + + // Auxiliary variables to avoid repeated arithmetic + float _2q1mx; + float _2q1my; + float _2q1mz; + float _2q2mx; + float _4bx; + float _4bz; + float _2q1 = 2.0f * q1; + float _2q2 = 2.0f * q2; + float _2q3 = 2.0f * q3; + float _2q4 = 2.0f * q4; + float _2q1q3 = 2.0f * q1 * q3; + float _2q3q4 = 2.0f * q3 * q4; + float q1q1 = q1 * q1; + float q1q2 = q1 * q2; + float q1q3 = q1 * q3; + float q1q4 = q1 * q4; + float q2q2 = q2 * q2; + float q2q3 = q2 * q3; + float q2q4 = q2 * q4; + float q3q3 = q3 * q3; + float q3q4 = q3 * q4; + float q4q4 = q4 * q4; - // Auxiliary variables to avoid repeated arithmetic - float _2q1mx; - float _2q1my; - float _2q1mz; - float _2q2mx; - float _4bx; - float _4bz; - float _2q1 = 2.0f * q1; - float _2q2 = 2.0f * q2; - float _2q3 = 2.0f * q3; - float _2q4 = 2.0f * q4; - float _2q1q3 = 2.0f * q1 * q3; - float _2q3q4 = 2.0f * q3 * q4; - float q1q1 = q1 * q1; - float q1q2 = q1 * q2; - float q1q3 = q1 * q3; - float q1q4 = q1 * q4; - float q2q2 = q2 * q2; - float q2q3 = q2 * q3; - float q2q4 = q2 * q4; - float q3q3 = q3 * q3; - float q3q4 = q3 * q4; - float q4q4 = q4 * q4; + // Normalise accelerometer measurement + norm = sqrt(ax * ax + ay * ay + az * az); + if (norm == 0.0f) return; // handle NaN + norm = 1.0f/norm; + ax *= norm; + ay *= norm; + az *= norm; + + // Normalise magnetometer measurement + norm = sqrt(mx * mx + my * my + mz * mz); + if (norm == 0.0f) return; // handle NaN + norm = 1.0f/norm; + mx *= norm; + my *= norm; + mz *= norm; - // Normalise accelerometer measurement - norm = sqrt(ax * ax + ay * ay + az * az); - if (norm == 0.0f) return; // handle NaN - norm = 1.0f/norm; - ax *= norm; - ay *= norm; - az *= norm; + // Reference direction of Earth's magnetic field + _2q1mx = 2.0f * q1 * mx; + _2q1my = 2.0f * q1 * my; + _2q1mz = 2.0f * q1 * mz; + _2q2mx = 2.0f * q2 * mx; + hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4; + hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4; + _2bx = sqrt(hx * hx + hy * hy); + _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4; + _4bx = 2.0f * _2bx; + _4bz = 2.0f * _2bz; + + // Gradient decent algorithm corrective step + s1 = -_2q3 * (2.0f * q2q4 - _2q1q3 - ax) + _2q2 * (2.0f * q1q2 + _2q3q4 - ay) - _2bz * q3 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q4 + _2bz * q2) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q3 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); + s2 = _2q4 * (2.0f * q2q4 - _2q1q3 - ax) + _2q1 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q2 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + _2bz * q4 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q3 + _2bz * q1) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q4 - _4bz * q2) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); + s3 = -_2q1 * (2.0f * q2q4 - _2q1q3 - ax) + _2q4 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q3 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + (-_4bx * q3 - _2bz * q1) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q2 + _2bz * q4) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q1 - _4bz * q3) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); + s4 = _2q2 * (2.0f * q2q4 - _2q1q3 - ax) + _2q3 * (2.0f * q1q2 + _2q3q4 - ay) + (-_4bx * q4 + _2bz * q2) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q1 + _2bz * q3) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q2 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); + norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude + norm = 1.0f/norm; + s1 *= norm; + s2 *= norm; + s3 *= norm; + s4 *= norm; + + // Compute rate of change of quaternion + qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1; + qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2; + qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3; + qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4; - // Normalise magnetometer measurement - norm = sqrt(mx * mx + my * my + mz * mz); - if (norm == 0.0f) return; // handle NaN - norm = 1.0f/norm; - mx *= norm; - my *= norm; - mz *= norm; + // Integrate to yield quaternion + q1 += qDot1 * deltat; + q2 += qDot2 * deltat; + q3 += qDot3 * deltat; + q4 += qDot4 * deltat; + norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion + norm = 1.0f/norm; + q[0] = q1 * norm; + q[1] = q2 * norm; + q[2] = q3 * norm; + q[3] = q4 * norm; + + } + + - // Reference direction of Earth's magnetic field - _2q1mx = 2.0f * q1 * mx; - _2q1my = 2.0f * q1 * my; - _2q1mz = 2.0f * q1 * mz; - _2q2mx = 2.0f * q2 * mx; - hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4; - hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4; - _2bx = sqrt(hx * hx + hy * hy); - _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4; - _4bx = 2.0f * _2bx; - _4bz = 2.0f * _2bz; +// Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and +// measured ones. + void MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz) { + float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability + float norm; + float hx, hy, bx, bz; + float vx, vy, vz, wx, wy, wz; + float ex, ey, ez; + float pa, pb, pc; + + // Auxiliary variables to avoid repeated arithmetic + float q1q1 = q1 * q1; + float q1q2 = q1 * q2; + float q1q3 = q1 * q3; + float q1q4 = q1 * q4; + float q2q2 = q2 * q2; + float q2q3 = q2 * q3; + float q2q4 = q2 * q4; + float q3q3 = q3 * q3; + float q3q4 = q3 * q4; + float q4q4 = q4 * q4; - // Gradient decent algorithm corrective step - s1 = -_2q3 * (2.0f * q2q4 - _2q1q3 - ax) + _2q2 * (2.0f * q1q2 + _2q3q4 - ay) - _2bz * q3 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q4 + _2bz * q2) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q3 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); - s2 = _2q4 * (2.0f * q2q4 - _2q1q3 - ax) + _2q1 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q2 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + _2bz * q4 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q3 + _2bz * q1) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q4 - _4bz * q2) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); - s3 = -_2q1 * (2.0f * q2q4 - _2q1q3 - ax) + _2q4 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q3 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + (-_4bx * q3 - _2bz * q1) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q2 + _2bz * q4) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q1 - _4bz * q3) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); - s4 = _2q2 * (2.0f * q2q4 - _2q1q3 - ax) + _2q3 * (2.0f * q1q2 + _2q3q4 - ay) + (-_4bx * q4 + _2bz * q2) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q1 + _2bz * q3) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q2 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz); - norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude - norm = 1.0f/norm; - s1 *= norm; - s2 *= norm; - s3 *= norm; - s4 *= norm; + // Normalise accelerometer measurement + norm = sqrt(ax * ax + ay * ay + az * az); + if (norm == 0.0f) return; // handle NaN + norm = 1.0f / norm; // use reciprocal for division + ax *= norm; + ay *= norm; + az *= norm; + + // Normalise magnetometer measurement + norm = sqrt(mx * mx + my * my + mz * mz); + if (norm == 0.0f) return; // handle NaN + norm = 1.0f / norm; // use reciprocal for division + mx *= norm; + my *= norm; + mz *= norm; - // Compute rate of change of quaternion - qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1; - qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2; - qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3; - qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4; + // Reference direction of Earth's magnetic field + hx = 2.0f * mx * (0.5f - q3q3 - q4q4) + 2.0f * my * (q2q3 - q1q4) + 2.0f * mz * (q2q4 + q1q3); + hy = 2.0f * mx * (q2q3 + q1q4) + 2.0f * my * (0.5f - q2q2 - q4q4) + 2.0f * mz * (q3q4 - q1q2); + bx = sqrt((hx * hx) + (hy * hy)); + bz = 2.0f * mx * (q2q4 - q1q3) + 2.0f * my * (q3q4 + q1q2) + 2.0f * mz * (0.5f - q2q2 - q3q3); - // Integrate to yield quaternion - q1 += qDot1 * deltat; - q2 += qDot2 * deltat; - q3 += qDot3 * deltat; - q4 += qDot4 * deltat; - norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion - norm = 1.0f/norm; - q[0] = q1 * norm; - q[1] = q2 * norm; - q[2] = q3 * norm; - q[3] = q4 * norm; + // Estimated direction of gravity and magnetic field + vx = 2.0f * (q2q4 - q1q3); + vy = 2.0f * (q1q2 + q3q4); + vz = q1q1 - q2q2 - q3q3 + q4q4; + wx = 2.0f * bx * (0.5f - q3q3 - q4q4) + 2.0f * bz * (q2q4 - q1q3); + wy = 2.0f * bx * (q2q3 - q1q4) + 2.0f * bz * (q1q2 + q3q4); + wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3); + // Error is cross product between estimated direction and measured direction of gravity + ex = (ay * vz - az * vy) + (my * wz - mz * wy); + ey = (az * vx - ax * vz) + (mz * wx - mx * wz); + ez = (ax * vy - ay * vx) + (mx * wy - my * wx); + if (Ki > 0.0f) { + eInt[0] += ex; // accumulate integral error + eInt[1] += ey; + eInt[2] += ez; + } else { + eInt[0] = 0.0f; // prevent integral wind up + eInt[1] = 0.0f; + eInt[2] = 0.0f; } - - - - // Similar to Madgwick scheme but uses proportional and integral filtering on the error between estimated reference vectors and - // measured ones. - void MahonyQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz) - { - float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability - float norm; - float hx, hy, bx, bz; - float vx, vy, vz, wx, wy, wz; - float ex, ey, ez; - float pa, pb, pc; + + // Apply feedback terms + gx = gx + Kp * ex + Ki * eInt[0]; + gy = gy + Kp * ey + Ki * eInt[1]; + gz = gz + Kp * ez + Ki * eInt[2]; + + // Integrate rate of change of quaternion + pa = q2; + pb = q3; + pc = q4; + q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * deltat); + q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * deltat); + q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * deltat); + q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * deltat); + + // Normalise quaternion + norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); + norm = 1.0f / norm; + q[0] = q1 * norm; + q[1] = q2 * norm; + q[2] = q3 * norm; + q[3] = q4 * norm; + + } +}; + +class IMU +{ + +public: + + void init(bool debug) { + + this->debug = debug; + i2c.frequency(400000); // use fast (400 kHz) I2C + Serial pc(USBTX,USBRX); + pc.baud(38400); + pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock); + + t.start(); + + // Read the WHO_AM_I register, this is a good test of communication + uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250); // Read WHO_AM_I register for MPU-9250 + pc.printf("I AM 0x%x\n\r", whoami); + pc.printf("I SHOULD BE 0x71\n\r"); + + if (whoami == 0x71) { // WHO_AM_I should always be 0x68 + pc.printf("MPU9250 WHO_AM_I is 0x%x\n\r", whoami); + pc.printf("MPU9250 is online...\n\r"); + sprintf(buffer, "0x%x", whoami); + + wait(1); - // Auxiliary variables to avoid repeated arithmetic - float q1q1 = q1 * q1; - float q1q2 = q1 * q2; - float q1q3 = q1 * q3; - float q1q4 = q1 * q4; - float q2q2 = q2 * q2; - float q2q3 = q2 * q3; - float q2q4 = q2 * q4; - float q3q3 = q3 * q3; - float q3q4 = q3 * q4; - float q4q4 = q4 * q4; + mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration + mpu9250.MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values + if (debug) + { + pc.printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]); + pc.printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]); + pc.printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]); + pc.printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]); + pc.printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]); + pc.printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]); + } + mpu9250.calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers + + if (debug) + { + pc.printf("x gyro bias = %f\n\r", gyroBias[0]); + pc.printf("y gyro bias = %f\n\r", gyroBias[1]); + pc.printf("z gyro bias = %f\n\r", gyroBias[2]); + pc.printf("x accel bias = %f\n\r", accelBias[0]); + pc.printf("y accel bias = %f\n\r", accelBias[1]); + pc.printf("z accel bias = %f\n\r", accelBias[2]); + } + + wait(2); + mpu9250.initMPU9250(); + pc.printf("MPU9250 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature + mpu9250.initAK8963(magCalibration); + pc.printf("AK8963 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer + if (debug) pc.printf("Accelerometer full-scale range = %f g\n\r", 2.0f*(float)(1<<Ascale)); + if (debug) pc.printf("Gyroscope full-scale range = %f deg/s\n\r", 250.0f*(float)(1<<Gscale)); + + if(Mscale == 0 && debug) pc.printf("Magnetometer resolution = 14 bits\n\r"); + if(Mscale == 1 && debug) pc.printf("Magnetometer resolution = 16 bits\n\r"); + if(Mmode == 2 && debug) pc.printf("Magnetometer ODR = 8 Hz\n\r"); + if(Mmode == 6 && debug) pc.printf("Magnetometer ODR = 100 Hz\n\r"); + wait(1); + } else { + pc.printf("Could not connect to MPU9250: \n\r"); + pc.printf("%#x \n", whoami); - // Normalise accelerometer measurement - norm = sqrt(ax * ax + ay * ay + az * az); - if (norm == 0.0f) return; // handle NaN - norm = 1.0f / norm; // use reciprocal for division - ax *= norm; - ay *= norm; - az *= norm; + + while(1) ; // Loop forever if communication doesn't happen + } - // Normalise magnetometer measurement - norm = sqrt(mx * mx + my * my + mz * mz); - if (norm == 0.0f) return; // handle NaN - norm = 1.0f / norm; // use reciprocal for division - mx *= norm; - my *= norm; - mz *= norm; - - // Reference direction of Earth's magnetic field - hx = 2.0f * mx * (0.5f - q3q3 - q4q4) + 2.0f * my * (q2q3 - q1q4) + 2.0f * mz * (q2q4 + q1q3); - hy = 2.0f * mx * (q2q3 + q1q4) + 2.0f * my * (0.5f - q2q2 - q4q4) + 2.0f * mz * (q3q4 - q1q2); - bx = sqrt((hx * hx) + (hy * hy)); - bz = 2.0f * mx * (q2q4 - q1q3) + 2.0f * my * (q3q4 + q1q2) + 2.0f * mz * (0.5f - q2q2 - q3q3); + mpu9250.getAres(); // Get accelerometer sensitivity + mpu9250.getGres(); // Get gyro sensitivity + mpu9250.getMres(); // Get magnetometer sensitivity + if (debug) pc.printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/aRes); + if (debug) pc.printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/gRes); + if (debug) pc.printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mRes); + magbias[0] = +470.; // User environmental x-axis correction in milliGauss, should be automatically calculated + magbias[1] = +120.; // User environmental x-axis correction in milliGauss + magbias[2] = +125.; // User environmental x-axis correction in milliGauss - // Estimated direction of gravity and magnetic field - vx = 2.0f * (q2q4 - q1q3); - vy = 2.0f * (q1q2 + q3q4); - vz = q1q1 - q2q2 - q3q3 + q4q4; - wx = 2.0f * bx * (0.5f - q3q3 - q4q4) + 2.0f * bz * (q2q4 - q1q3); - wy = 2.0f * bx * (q2q3 - q1q4) + 2.0f * bz * (q1q2 + q3q4); - wz = 2.0f * bx * (q1q3 + q2q4) + 2.0f * bz * (0.5f - q2q2 - q3q3); + + yawZero=0; + rollZero=0; + pitchZero=0; + + + } + + void update() { + // If intPin goes high, all data registers have new data + if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) { // On interrupt, check if data ready interrupt + + mpu9250.readAccelData(accelCount); // Read the x/y/z adc values + // Now we'll calculate the accleration value into actual g's + ax = (float)accelCount[0]*aRes - accelBias[0]; // get actual g value, this depends on scale being set + ay = (float)accelCount[1]*aRes - accelBias[1]; + az = (float)accelCount[2]*aRes - accelBias[2]; + + mpu9250.readGyroData(gyroCount); // Read the x/y/z adc values + // Calculate the gyro value into actual degrees per second + gx = (float)gyroCount[0]*gRes - gyroBias[0]; // get actual gyro value, this depends on scale being set + gy = (float)gyroCount[1]*gRes - gyroBias[1]; + gz = (float)gyroCount[2]*gRes - gyroBias[2]; - // Error is cross product between estimated direction and measured direction of gravity - ex = (ay * vz - az * vy) + (my * wz - mz * wy); - ey = (az * vx - ax * vz) + (mz * wx - mx * wz); - ez = (ax * vy - ay * vx) + (mx * wy - my * wx); - if (Ki > 0.0f) - { - eInt[0] += ex; // accumulate integral error - eInt[1] += ey; - eInt[2] += ez; - } - else - { - eInt[0] = 0.0f; // prevent integral wind up - eInt[1] = 0.0f; - eInt[2] = 0.0f; - } + mpu9250.readMagData(magCount); // Read the x/y/z adc values + // Calculate the magnetometer values in milliGauss + // Include factory calibration per data sheet and user environmental corrections + mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0]; // get actual magnetometer value, this depends on scale being set + my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1]; + mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2]; + } + + Now = t.read_us(); + deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update + lastUpdate = Now; + + sum += deltat; + sumCount++; + +// if(lastUpdate - firstUpdate > 10000000.0f) { +// beta = 0.04; // decrease filter gain after stabilized +// zeta = 0.015; // increasey bias drift gain after stabilized +// } + + // Pass gyro rate as rad/s + //mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz); + mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz); + } - // Apply feedback terms - gx = gx + Kp * ex + Ki * eInt[0]; - gy = gy + Kp * ey + Ki * eInt[1]; - gz = gz + Kp * ez + Ki * eInt[2]; + void setZero() { + rollZero = getRollRelative(); + pitchZero = getPitchRelative(); + yawZero = getYawRelative(); + } + + void updateRollAbsolute() { + roll = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]); + roll *= 180.0f / PI; + + } + + void updatePitchAbsolute() { + pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2])); + pitch *= 180.0f / PI; + } + + void updateYawAbsolute() { + yaw = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]); + yaw *= 180.0f / PI; + } + + float getRollRelative() { + float res = roll - rollZero; + if (debug) printf("[d] Roll relative value: %f\n\r", res); + return res; + } - // Integrate rate of change of quaternion - pa = q2; - pb = q3; - pc = q4; - q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * deltat); - q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * deltat); - q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * deltat); - q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * deltat); + float getPitchRelative() { + float res = pitch - pitchZero; + if (debug) printf("[d] Pitch relative value: %f\n\r", res); + return res; + } + + float getYawRelative() { + float res = yaw - yawZero; + if (debug) printf("[d] Yaw relative value: %f\n\r", res); + return res; + } + + + - // Normalise quaternion - norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); - norm = 1.0f / norm; - q[0] = q1 * norm; - q[1] = q2 * norm; - q[2] = q3 * norm; - q[3] = q4 * norm; - - } - }; +private: + + + + float rollZero, pitchZero, yawZero; + bool debug; + Timer t; + float sum; + uint32_t sumCount; + char buffer[14]; + + MPU9250 mpu9250; +}; + #endif \ No newline at end of file
--- a/N5110.lib Tue Aug 05 01:37:23 2014 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,1 +0,0 @@ -http://mbed.org/users/onehorse/code/Adfs/#28c629d0b0d0
--- a/main.cpp Tue Aug 05 01:37:23 2014 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,254 +0,0 @@ -/* MPU9250 Basic Example Code - by: Kris Winer - date: April 1, 2014 - license: Beerware - Use this code however you'd like. If you - find it useful you can buy me a beer some time. - - Demonstrate basic MPU-9250 functionality including parameterizing the register addresses, initializing the sensor, - getting properly scaled accelerometer, gyroscope, and magnetometer data out. Added display functions to - allow display to on breadboard monitor. Addition of 9 DoF sensor fusion using open source Madgwick and - Mahony filter algorithms. Sketch runs on the 3.3 V 8 MHz Pro Mini and the Teensy 3.1. - - SDA and SCL should have external pull-up resistors (to 3.3V). - 10k resistors are on the EMSENSR-9250 breakout board. - - Hardware setup: - MPU9250 Breakout --------- Arduino - VDD ---------------------- 3.3V - VDDI --------------------- 3.3V - SDA ----------------------- A4 - SCL ----------------------- A5 - GND ---------------------- GND - - Note: The MPU9250 is an I2C sensor and uses the Arduino Wire library. - Because the sensor is not 5V tolerant, we are using a 3.3 V 8 MHz Pro Mini or a 3.3 V Teensy 3.1. - We have disabled the internal pull-ups used by the Wire library in the Wire.h/twi.c utility file. - We are also using the 400 kHz fast I2C mode by setting the TWI_FREQ to 400000L /twi.h utility file. - */ - -//#include "ST_F401_84MHZ.h" -//F401_init84 myinit(0); -#include "mbed.h" -#include "MPU9250.h" -#include "N5110.h" - -// Using NOKIA 5110 monochrome 84 x 48 pixel display -// pin 9 - Serial clock out (SCLK) -// pin 8 - Serial data out (DIN) -// pin 7 - Data/Command select (D/C) -// pin 5 - LCD chip select (CS) -// pin 6 - LCD reset (RST) -//Adafruit_PCD8544 display = Adafruit_PCD8544(9, 8, 7, 5, 6); - -float sum = 0; -uint32_t sumCount = 0; -char buffer[14]; - - MPU9250 mpu9250; - - Timer t; - - Serial pc(USBTX, USBRX); // tx, rx - - // VCC, SCE, RST, D/C, MOSI,S CLK, LED - N5110 lcd(PA_8, PB_10, PA_9, PA_6, PA_7, PA_5, PC_7); - - - -int main() -{ - pc.baud(9600); - - //Set up I2C - i2c.frequency(400000); // use fast (400 kHz) I2C - - pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock); - - t.start(); - - lcd.init(); -// lcd.setBrightness(0.05); - - - // Read the WHO_AM_I register, this is a good test of communication - uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250); // Read WHO_AM_I register for MPU-9250 - pc.printf("I AM 0x%x\n\r", whoami); pc.printf("I SHOULD BE 0x71\n\r"); - - if (whoami == 0x71) // WHO_AM_I should always be 0x68 - { - pc.printf("MPU9250 WHO_AM_I is 0x%x\n\r", whoami); - pc.printf("MPU9250 is online...\n\r"); - lcd.clear(); - lcd.printString("MPU9250 is", 0, 0); - sprintf(buffer, "0x%x", whoami); - lcd.printString(buffer, 0, 1); - lcd.printString("shoud be 0x71", 0, 2); - wait(1); - - mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration - mpu9250.MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values - pc.printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]); - pc.printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]); - pc.printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]); - pc.printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]); - pc.printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]); - pc.printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]); - mpu9250.calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers - pc.printf("x gyro bias = %f\n\r", gyroBias[0]); - pc.printf("y gyro bias = %f\n\r", gyroBias[1]); - pc.printf("z gyro bias = %f\n\r", gyroBias[2]); - pc.printf("x accel bias = %f\n\r", accelBias[0]); - pc.printf("y accel bias = %f\n\r", accelBias[1]); - pc.printf("z accel bias = %f\n\r", accelBias[2]); - wait(2); - mpu9250.initMPU9250(); - pc.printf("MPU9250 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature - mpu9250.initAK8963(magCalibration); - pc.printf("AK8963 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer - pc.printf("Accelerometer full-scale range = %f g\n\r", 2.0f*(float)(1<<Ascale)); - pc.printf("Gyroscope full-scale range = %f deg/s\n\r", 250.0f*(float)(1<<Gscale)); - if(Mscale == 0) pc.printf("Magnetometer resolution = 14 bits\n\r"); - if(Mscale == 1) pc.printf("Magnetometer resolution = 16 bits\n\r"); - if(Mmode == 2) pc.printf("Magnetometer ODR = 8 Hz\n\r"); - if(Mmode == 6) pc.printf("Magnetometer ODR = 100 Hz\n\r"); - wait(1); - } - else - { - pc.printf("Could not connect to MPU9250: \n\r"); - pc.printf("%#x \n", whoami); - - lcd.clear(); - lcd.printString("MPU9250", 0, 0); - lcd.printString("no connection", 0, 1); - sprintf(buffer, "WHO_AM_I 0x%x", whoami); - lcd.printString(buffer, 0, 2); - - while(1) ; // Loop forever if communication doesn't happen - } - - mpu9250.getAres(); // Get accelerometer sensitivity - mpu9250.getGres(); // Get gyro sensitivity - mpu9250.getMres(); // Get magnetometer sensitivity - pc.printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/aRes); - pc.printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/gRes); - pc.printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mRes); - magbias[0] = +470.; // User environmental x-axis correction in milliGauss, should be automatically calculated - magbias[1] = +120.; // User environmental x-axis correction in milliGauss - magbias[2] = +125.; // User environmental x-axis correction in milliGauss - - while(1) { - - // If intPin goes high, all data registers have new data - if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) { // On interrupt, check if data ready interrupt - - mpu9250.readAccelData(accelCount); // Read the x/y/z adc values - // Now we'll calculate the accleration value into actual g's - ax = (float)accelCount[0]*aRes - accelBias[0]; // get actual g value, this depends on scale being set - ay = (float)accelCount[1]*aRes - accelBias[1]; - az = (float)accelCount[2]*aRes - accelBias[2]; - - mpu9250.readGyroData(gyroCount); // Read the x/y/z adc values - // Calculate the gyro value into actual degrees per second - gx = (float)gyroCount[0]*gRes - gyroBias[0]; // get actual gyro value, this depends on scale being set - gy = (float)gyroCount[1]*gRes - gyroBias[1]; - gz = (float)gyroCount[2]*gRes - gyroBias[2]; - - mpu9250.readMagData(magCount); // Read the x/y/z adc values - // Calculate the magnetometer values in milliGauss - // Include factory calibration per data sheet and user environmental corrections - mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0]; // get actual magnetometer value, this depends on scale being set - my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1]; - mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2]; - } - - Now = t.read_us(); - deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update - lastUpdate = Now; - - sum += deltat; - sumCount++; - -// if(lastUpdate - firstUpdate > 10000000.0f) { -// beta = 0.04; // decrease filter gain after stabilized -// zeta = 0.015; // increasey bias drift gain after stabilized - // } - - // Pass gyro rate as rad/s -// mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz); - mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz); - - // Serial print and/or display at 0.5 s rate independent of data rates - delt_t = t.read_ms() - count; - if (delt_t > 500) { // update LCD once per half-second independent of read rate - - pc.printf("ax = %f", 1000*ax); - pc.printf(" ay = %f", 1000*ay); - pc.printf(" az = %f mg\n\r", 1000*az); - - pc.printf("gx = %f", gx); - pc.printf(" gy = %f", gy); - pc.printf(" gz = %f deg/s\n\r", gz); - - pc.printf("gx = %f", mx); - pc.printf(" gy = %f", my); - pc.printf(" gz = %f mG\n\r", mz); - - tempCount = mpu9250.readTempData(); // Read the adc values - temperature = ((float) tempCount) / 333.87f + 21.0f; // Temperature in degrees Centigrade - pc.printf(" temperature = %f C\n\r", temperature); - - pc.printf("q0 = %f\n\r", q[0]); - pc.printf("q1 = %f\n\r", q[1]); - pc.printf("q2 = %f\n\r", q[2]); - pc.printf("q3 = %f\n\r", q[3]); - -/* lcd.clear(); - lcd.printString("MPU9250", 0, 0); - lcd.printString("x y z", 0, 1); - sprintf(buffer, "%d %d %d mg", (int)(1000.0f*ax), (int)(1000.0f*ay), (int)(1000.0f*az)); - lcd.printString(buffer, 0, 2); - sprintf(buffer, "%d %d %d deg/s", (int)gx, (int)gy, (int)gz); - lcd.printString(buffer, 0, 3); - sprintf(buffer, "%d %d %d mG", (int)mx, (int)my, (int)mz); - lcd.printString(buffer, 0, 4); - */ - // Define output variables from updated quaternion---these are Tait-Bryan angles, commonly used in aircraft orientation. - // In this coordinate system, the positive z-axis is down toward Earth. - // Yaw is the angle between Sensor x-axis and Earth magnetic North (or true North if corrected for local declination, looking down on the sensor positive yaw is counterclockwise. - // Pitch is angle between sensor x-axis and Earth ground plane, toward the Earth is positive, up toward the sky is negative. - // Roll is angle between sensor y-axis and Earth ground plane, y-axis up is positive roll. - // These arise from the definition of the homogeneous rotation matrix constructed from quaternions. - // Tait-Bryan angles as well as Euler angles are non-commutative; that is, the get the correct orientation the rotations must be - // applied in the correct order which for this configuration is yaw, pitch, and then roll. - // For more see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles which has additional links. - yaw = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]); - pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2])); - roll = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]); - pitch *= 180.0f / PI; - yaw *= 180.0f / PI; - yaw -= 13.8f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04 - roll *= 180.0f / PI; - - pc.printf("Yaw, Pitch, Roll: %f %f %f\n\r", yaw, pitch, roll); - pc.printf("average rate = %f\n\r", (float) sumCount/sum); -// sprintf(buffer, "YPR: %f %f %f", yaw, pitch, roll); -// lcd.printString(buffer, 0, 4); -// sprintf(buffer, "rate = %f", (float) sumCount/sum); -// lcd.printString(buffer, 0, 5); - - myled= !myled; - count = t.read_ms(); - - if(count > 1<<21) { - t.start(); // start the timer over again if ~30 minutes has passed - count = 0; - deltat= 0; - lastUpdate = t.read_us(); - } - sum = 0; - sumCount = 0; -} -} - - } \ No newline at end of file