Zoltan Hudak
Library for MPU6050 motion sensor with Madgwick filter.
Dependents: ScilabArduino MPU6050_Hello
Revision 0:9c2bb0f94c31, committed 2021-01-18
- Comitter:
- hudakz
- Date:
- Mon Jan 18 19:44:43 2021 +0000
- Commit message:
- Library for MPU6050 with Madgwick filter.
Changed in this revision
| MPU6050.cpp | Show annotated file Show diff for this revision Revisions of this file |
| MPU6050.h | Show annotated file Show diff for this revision Revisions of this file |
diff -r 000000000000 -r 9c2bb0f94c31 MPU6050.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MPU6050.cpp Mon Jan 18 19:44:43 2021 +0000
@@ -0,0 +1,826 @@
+#include "MPU6050.h"
+
+/**
+ * @brief Creates an MPU6050 object
+ * @note Default address is 0x68
+ * Default acceleration range 2G
+ * Default gyroscope range is 250 dps (degrees per second)
+ * I2C_SDA and I2C_SCL pins are used for I2C connection by default
+ * Interrupt pin is not connected (NC) by default
+ * @param
+ * @retval
+ */
+MPU6050::MPU6050
+(
+ uint8_t addr /*= 0x68*/,
+ AccelScale accelScale /*= AFS_2G*/,
+ GyroScale gyroScale /*= GFS_250DPS*/,
+ PinName sdaPin /*= I2C_SDA*/,
+ PinName sclPin /*= I2C_SCL*/,
+ PinName interruptInPin /*= NC*/
+) :
+ _addr(addr << 1),
+ _accelScale(accelScale),
+ _gyroScale(gyroScale),
+ _i2c(sdaPin, sclPin),
+ _interruptIn(interruptInPin),
+ _accelRes(0),
+ _gyroRes(0),
+ _beta(sqrt(3.0f / 4.0f) * _gyroError),
+ _zeta(sqrt(3.0f / 4.0f) * _gyroDrift)
+{
+ _i2c.frequency(400000); // 400 kHz
+}
+
+/**
+ * @brief
+ * @note
+ * @param
+ * @retval
+ */
+void MPU6050::rise(Callback<void (void)> func)
+{
+ _interruptIn.rise(func);
+}
+
+/**
+ * @brief
+ * @note
+ * @param
+ * @retval
+ */
+template<typename T>
+void MPU6050::rise(T* tptr, void (T:: *mptr) (void))
+{
+ if ((mptr != NULL) && (tptr != NULL))
+ _interruptIn.rise(tptr, &T::mptr);
+}
+
+/**
+ * @brief
+ * @note
+ * @param
+ * @retval
+ */
+void MPU6050::fall(Callback<void (void)> func)
+{
+ _interruptIn.fall(func);
+}
+
+/**
+ * @brief
+ * @note
+ * @param
+ * @retval
+ */
+template<typename T>
+void MPU6050::fall(T* tptr, void (T:: *mptr) (void))
+{
+ if ((mptr != NULL) && (tptr != NULL))
+ _interruptIn.fall(tptr, &T::mptr);
+}
+
+/**
+ * @brief Writes a byte to register
+ * @note
+ * @param
+ * @retval
+ */
+void MPU6050::writeReg(uint8_t reg, uint8_t byte)
+{
+ char data[2];
+
+ data[0] = reg;
+ data[1] = byte;
+ _i2c.write(_addr, data, sizeof(data), false);
+}
+
+/**
+ * @brief Reads byte from a register
+ * @note
+ * @param
+ * @retval
+ */
+uint8_t MPU6050::readReg(uint8_t reg)
+{
+ char ret; // `ret` will store the register data
+
+ _i2c.write(_addr, (const char*) ®, 1, 1); // no stop
+ _i2c.read(_addr, &ret, 1, 0);
+ return ret;
+}
+
+/**
+ * @brief Read multiple bytes from a register
+ * @note
+ * @param
+ * @retval
+ */
+void MPU6050::readRegBytes(uint8_t reg, uint8_t len, uint8_t* dest)
+{
+ _i2c.write(_addr, (const char*) ®, 1, 1); // no stop
+ _i2c.read(_addr, (char*)dest, len, 0);
+}
+
+/**
+ * @brief Initializes the MPU6050
+ * @note
+ * @param
+ * @retval
+ */
+bool MPU6050::init()
+{
+ uint8_t c;
+
+ writeReg(PWR_MGMT_1, 0x00); // Select internal OSC as clock source, clear sleep mode bit (6), enable all sensors
+
+ // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt
+#if MBED_MAJOR_VERSION > 5
+ ThisThread::sleep_for(100ms);
+#else
+ wait_ms(100);
+#endif
+ //
+
+ // get stable time source
+ writeReg(PWR_MGMT_1, 0x01); // Select PLL with x-axis gyroscope reference as clock source, bits 2:0 = 001
+
+ // Configure Gyro and Accelerometer
+ // DLPF_CFG = bits 2:0 = 0x03 (0b010)
+ // Sets the sample rate to 1 kHz for Low Pass Filter (DLPF) for both the accelerometers and gyros
+ // disables FSYNC and sets accelerometer and gyro bandwidth to 44 and 42 Hz, respectively;
+ // Maximum delay is 4.9 ms (= 204.08 Hz) which is just over a 200 Hz maximum rate
+ writeReg(CONFIG, 0x03);
+
+ // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
+ // Where gyroscope output rate = 1kHz when the DLPF is disabled (DLPF_CFG = 0 or 7)
+ // Use a 200 Hz rate; the same rate set in CONFIG above: 200 = 1000/(1 + 4)
+ writeReg(SMPLRT_DIV, 0x04);
+
+ // Set gyroscope full scale range
+ c = readReg(GYRO_CONFIG); // Read the GYRO_CONFIG register
+ c &= 0b11100000; // Clear self-test bits [7:5]
+
+ // Range selectors FS_SEL is 0 - 3, so left-shift 2-bit value into positions 4:3
+ c |= (_gyroScale << 3); // Set FS_SEL bits [4:3]
+ writeReg(GYRO_CONFIG, c); // Set the full scale range for the gyro
+
+ // Update gyro scale according to the selected gyro full scale range.
+ // Possible gyro scales (and their register bit settings) are:
+ // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11).
+ // Set DPS/(ADC tick) based on that 2-bit value:
+ switch (_gyroScale) {
+ case GFS_250DPS:
+ _gyroRes = 250.0 / 32768.0;
+ break;
+
+ case GFS_500DPS:
+ _gyroRes = 500.0 / 32768.0;
+ break;
+
+ case GFS_1000DPS:
+ _gyroRes = 1000.0 / 32768.0;
+ break;
+
+ case GFS_2000DPS:
+ _gyroRes = 2000.0 / 32768.0;
+ break;
+ }
+
+ // Set accelerometer configuration
+ c = readReg(ACCEL_CONFIG); // Read the ACCEL_CONFIG register
+ c &= 0b11100000; // Clear self-test bits [7:5]
+
+ // Range selectors AFS_SEL is 0 - 3, so left-shift 2-bit value into positions 4:3
+ c |= (_accelScale << 3);
+ writeReg(ACCEL_CONFIG, c); // Set full scale range for the accelerometer
+
+ // Update acceleration scle to the selected acceleration scale range.
+ // 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:
+ switch (_accelScale) {
+ case AFS_2G:
+ _accelRes = 2.0 / 32768.0;
+ break;
+
+ case AFS_4G:
+ _accelRes = 4.0 / 32768.0;
+ break;
+
+ case AFS_8G:
+ _accelRes = 8.0 / 32768.0;
+ break;
+
+ case AFS_16G:
+ _accelRes = 16.0 / 32768.0;
+ break;
+ }
+
+ // Configure Interrupts and Bypass Enable
+ // When bit [7] (INT_LEVEL) is equal to 0, the logic level for the INT pin is active high.
+ // When bit [6] (INT_OPEN) is equal to 0, the INT pin is configured as push-pull.
+ // When bit [5] (LATCH_INT_EN) is equal to 1, the INT pin is held high until the interrupt is cleared.
+ // When bit [4] (INT_RD_CLEAR) is equal to 0, interrupt status bits are cleared only by reading INT_STATUS
+ // When bit [3] (FSYNC_INT_LEVEL) is equal to 0, the logic level for the FSYNC pin
+ // (when used as an interrupt to the host processor) is active high.
+ // When bit [2] (FSYNC_INT_EN) is equal to 0, this bit disables the FSYNC pin from causing
+ // an interrupt to the host processor.
+ // When bit [1] (I2C_BYPASS_EN) is equal to 1 and bit [5] (I2C_MST_EN) in the USER_CTRL register) is equal to 0,
+ // the host application processor will be able to directly access the auxiliary I2C bus of the MPU-60X0.
+ writeReg(INT_PIN_CFG, 0b00100010);
+
+ // Clear bit [5] in the USER_CTRL register
+ c = readReg(USER_CTRL);
+ c &= ~(1 << I2C_MST_EN);
+ writeReg(USER_CTRL, c);
+
+ // Enable data ready interrupt (bit [0])
+ writeReg(INT_ENABLE, 0x01);
+
+ return true;
+}
+
+/**
+ * @brief Indicates whether data is available after an interrupt
+ * @note The DATA_RDY_INT bit clears to 0 after the INT_STATUS register has been read.
+ * @param
+ * @retval
+ */
+bool MPU6050::dataReady()
+{
+ return(readReg(INT_STATUS) & (1 << DATA_RDY_INT));
+}
+
+/**
+ * @brief Reads acceleration ADC (analog to digital converter)
+ * @note
+ * @param
+ * @retval Acceleration ADC array of three elements
+ */
+int16_t* MPU6050::accelADC()
+{
+ uint8_t rawData[6]; // x/y/z accel register data stored here
+
+ readRegBytes(ACCEL_XOUT_H, 6, rawData); // Read the six raw data registers into data array
+ _accelAdc[0] = int16_t(rawData[0]) << 8 | rawData[1]; // Turn the MSB and LSB into a signed 16-bit value
+ _accelAdc[1] = int16_t(rawData[2]) << 8 | rawData[3];
+ _accelAdc[2] = int16_t(rawData[4]) << 8 | rawData[5];
+
+ return _accelAdc;
+}
+
+/**
+ * @brief Reads gyro ADC (analog to digital converter)
+ * @note
+ * @param
+ * @retval Gyro ADC array of three elements
+ */
+int16_t* MPU6050::gyroADC()
+{
+ uint8_t rawData[6]; // x/y/z gyro register data stored here
+
+ readRegBytes(GYRO_XOUT_H, 6, rawData); // Read the six raw data registers sequentially into data array
+ _gyroAdc[0] = int16_t(rawData[0]) << 8 | rawData[1]; // Turn the MSB and LSB into a signed 16-bit value
+ _gyroAdc[1] = int16_t(rawData[2]) << 8 | rawData[3];
+ _gyroAdc[2] = int16_t(rawData[4]) << 8 | rawData[5];
+
+ return _gyroAdc;
+}
+
+/**
+ * @brief Reads temperature ADC (analog to digital converter)
+ * @note
+ * @param
+ * @retval Temperature ADC value
+ */
+int16_t MPU6050::tempADC()
+{
+ uint8_t rawData[2]; // x/y/z gyro register data stored here
+
+ readRegBytes(TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array
+ return int16_t(rawData[0]) << 8 | rawData[1]; // Turn the MSB and LSB into a 16-bit value
+}
+
+/**
+ * @brief
+ * @note
+ * @param
+ * @retval
+ */
+float MPU6050::temp()
+{
+ return(tempADC() / 340. + 36.53); // Temperature in degrees Celsius
+}
+
+/**
+ * @brief Configures the motion detection control for low power accelerometer mode
+ * @note The sensor has a high-pass filter necessary to invoke to allow the sensor motion detection algorithms work properly
+ * Motion detection occurs on free-fall (acceleration below a threshold for some time for all axes), motion (acceleration
+ * above a threshold for some time on at least one axis), and zero-motion toggle (acceleration on each axis less than a
+ * threshold for some time sets this flag, motion above the threshold turns it off). The high-pass filter takes gravity out
+ * consideration for these threshold evaluations; otherwise, the flags would be set all the time!
+ * @param
+ * @retval
+ */
+void MPU6050::lowPowerAccelOnly()
+{
+ uint8_t c = readReg(PWR_MGMT_1);
+ writeReg(PWR_MGMT_1, c &~0x30); // Clear sleep and cycle bits [5:6]
+ writeReg(PWR_MGMT_1, c | 0x30); // Set sleep and cycle bits [5:6] to zero to make sure accelerometer is running
+ c = readReg(PWR_MGMT_2);
+ writeReg(PWR_MGMT_2, c &~0x38); // Clear standby XA, YA, and ZA bits [3:5]
+ writeReg(PWR_MGMT_2, c | 0x00); // Set XA, YA, and ZA bits [3:5] to zero to make sure accelerometer is running
+ c = readReg(ACCEL_CONFIG);
+ writeReg(ACCEL_CONFIG, c &~0x07); // Clear high-pass filter bits [2:0]
+
+ // Set high-pass filter to 0) reset (disable), 1) 5 Hz, 2) 2.5 Hz, 3) 1.25 Hz, 4) 0.63 Hz, or 7) Hold
+ writeReg(ACCEL_CONFIG, c | 0x00); // Set ACCEL_HPF to 0; reset mode disbaling high-pass filter
+ c = readReg(CONFIG);
+ writeReg(CONFIG, c &~0x07); // Clear low-pass filter bits [2:0]
+ writeReg(CONFIG, c | 0x00); // Set DLPD_CFG to 0; 260 Hz bandwidth, 1 kHz rate
+ c = readReg(INT_ENABLE);
+ writeReg(INT_ENABLE, c &~0xFF); // Clear all interrupts
+ writeReg(INT_ENABLE, 0x40); // Enable motion threshold (bits 5) interrupt only
+
+ // Motion detection interrupt requires the absolute value of any axis to lie above the detection threshold
+ // for at least the counter duration
+ writeReg(MOT_THR, 0x80); // Set motion detection to 0.256 g; LSB = 2 mg
+ writeReg(MOT_DUR, 0x01); // Set motion detect duration to 1 ms; LSB is 1 ms @ 1 kHz rate
+
+ // Add delay for accumulation of samples
+#if MBED_MAJOR_VERSION > 5
+ ThisThread::sleep_for(100ms);
+#else
+ wait_ms(100);
+#endif
+ c = readReg(ACCEL_CONFIG);
+ writeReg(ACCEL_CONFIG, c &~0x07); // Clear high-pass filter bits [2:0]
+ writeReg(ACCEL_CONFIG, c | 0x07); // Set ACCEL_HPF to 7; hold the initial accleration value as a referance
+ c = readReg(PWR_MGMT_2);
+ writeReg(PWR_MGMT_2, c &~0xC7); // Clear standby XA, YA, and ZA bits [3:5] and LP_WAKE_CTRL bits [6:7]
+ writeReg(PWR_MGMT_2, c | 0x47); // Set wakeup frequency to 5 Hz, and disable XG, YG, and ZG gyros (bits [0:2])
+ c = readReg(PWR_MGMT_1);
+ writeReg(PWR_MGMT_1, c &~0x20); // Clear sleep and cycle bit 5
+ writeReg(PWR_MGMT_1, c | 0x20); // Set cycle bit 5 to begin low power accelerometer motion interrupts
+}
+
+/**
+ * @brief Resets the MPU6050
+ * @note
+ * @param
+ * @retval
+ */
+void MPU6050::reset()
+{
+ // Reset the device
+
+ writeReg(PWR_MGMT_1, 0b10000000); // Write a one to bit 7 (reset bit);
+#if MBED_MAJOR_VERSION > 5
+ ThisThread::sleep_for(100ms);
+#else
+ wait_ms(100);
+#endif
+}
+
+/**
+ * @brief Calibrates the MPU6050
+ * @note 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.
+ * @param
+ * @retval
+ */
+void MPU6050::calibrate()
+{
+ uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data
+ uint16_t packetCount, fifoCount;
+ int32_t gyroBias[3] = { 0, 0, 0 };
+ int32_t accelBias[3] = { 0, 0, 0 };
+
+ // Reset the device, reset all registers, clear gyro and accelerometer bias registers
+
+ reset();
+
+ // Get stable time source: set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
+ writeReg(PWR_MGMT_1, 0x01);
+ writeReg(PWR_MGMT_2, 0x00);
+#if MBED_MAJOR_VERSION > 5
+ ThisThread::sleep_for(200ms);
+#else
+ wait_ms(200);
+#endif
+ //
+
+ // Configure the device for bias calculation
+ writeReg(INT_ENABLE, 0x00); // Disable all interrupts
+ writeReg(FIFO_EN, 0x00); // Disable FIFO
+ writeReg(PWR_MGMT_1, 0x00); // Turn on internal clock source
+ writeReg(I2C_MST_CTRL, 0x00); // Disable I2C master
+ writeReg(USER_CTRL, 0x00); // Disable FIFO and I2C master modes
+ writeReg(USER_CTRL, 0x0C); // Reset FIFO and DMP
+#if MBED_MAJOR_VERSION > 5
+ ThisThread::sleep_for(200ms);
+#else
+ wait_ms(200);
+#endif
+ // Configure MPU6050 gyro and accelerometer for bias calculation
+
+ writeReg(CONFIG, 0x01); // Set low-pass filter to 188 Hz
+ writeReg(SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
+ writeReg(GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
+ writeReg(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
+ writeReg(USER_CTRL, 0x40); // Enable FIFO
+ writeReg(FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 1024 bytes in MPU-6050)
+
+ // accumulate 80 samples in 80 milliseconds = 960 bytes
+#if MBED_MAJOR_VERSION > 5
+ ThisThread::sleep_for(80ms);
+#else
+ wait_ms(80);
+#endif
+ //
+
+ // At end of sample accumulation, turn off FIFO sensor read
+ writeReg(FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO
+ readRegBytes(FIFO_COUNTH, 2, &data[0]); // read FIFO sample count
+ fifoCount = ((uint16_t) data[0] << 8) | data[1];
+ packetCount = fifoCount / 12; // How many sets of full gyro and accelerometer data for averaging
+ for (int i = 0; i < packetCount; i++) {
+ int16_t accel_temp[3] = { 0, 0, 0 },
+ gyro_temp[3] = { 0, 0, 0 };
+ readRegBytes(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]);
+
+ accelBias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
+ accelBias[1] += (int32_t) accel_temp[1];
+ accelBias[2] += (int32_t) accel_temp[2];
+ gyroBias[0] += (int32_t) gyro_temp[0];
+ gyroBias[1] += (int32_t) gyro_temp[1];
+ gyroBias[2] += (int32_t) gyro_temp[2];
+ }
+
+ accelBias[0] /= (int32_t) packetCount; // Normalize sums to get average count biases
+ accelBias[1] /= (int32_t) packetCount;
+ accelBias[2] /= (int32_t) packetCount;
+ gyroBias[0] /= (int32_t) packetCount;
+ gyroBias[1] /= (int32_t) packetCount;
+ gyroBias[2] /= (int32_t) packetCount;
+
+ if (accelBias[2] > 0L) {
+ accelBias[2] -= (int32_t) accelSensitivity;
+ } // Remove gravity from the z-axis accelerometer bias calculation
+ else {
+ accelBias[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] = (-gyroBias[0] / 4 >> 8) & 0xFF; // Divide by 4 to get 32.9 LSB per deg/s to conform to expected bias input format
+ data[1] = (-gyroBias[0] / 4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
+ data[2] = (-gyroBias[1] / 4 >> 8) & 0xFF;
+ data[3] = (-gyroBias[1] / 4) & 0xFF;
+ data[4] = (-gyroBias[2] / 4 >> 8) & 0xFF;
+ data[5] = (-gyroBias[2] / 4) & 0xFF;
+
+ // Push gyro biases to hardware registers
+ writeReg(XG_OFFS_USRH, data[0]);
+ writeReg(XG_OFFS_USRL, data[1]);
+ writeReg(YG_OFFS_USRH, data[2]);
+ writeReg(YG_OFFS_USRL, data[3]);
+ writeReg(ZG_OFFS_USRH, data[4]);
+ writeReg(ZG_OFFS_USRL, data[5]);
+
+ _gyroBias[0] = (float)gyroBias[0] / (float)gyroSensitivity; // construct gyro bias in deg/s for later manual subtraction
+ _gyroBias[1] = (float)gyroBias[1] / (float)gyroSensitivity;
+ _gyroBias[2] = (float)gyroBias[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
+ // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
+ // 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
+
+ readRegBytes(XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
+ accel_bias_reg[0] = (int16_t) ((int16_t) data[0] << 8) | data[1];
+ readRegBytes(YA_OFFSET_H, 2, &data[0]);
+ accel_bias_reg[1] = (int16_t) ((int16_t) data[0] << 8) | data[1];
+ readRegBytes(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 (int i = 0; i < 3; i++) {
+ if (accel_bias_reg[i] & mask)
+ mask_bit[i] = 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] -= (accelBias[0] / 8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
+ accel_bias_reg[1] -= (accelBias[1] / 8);
+ accel_bias_reg[2] -= (accelBias[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
+
+ // Push accelerometer biases to hardware registers
+ // writeByte(_address, XA_OFFSET_H, data[0]);
+ // writeByte(_address, XA_OFFSET_L_TC, data[1]);
+ // writeByte(_address, YA_OFFSET_H, data[2]);
+ // writeByte(_address, YA_OFFSET_L_TC, data[3]);
+ // writeByte(_address, ZA_OFFSET_H, data[4]);
+ // writeByte(_address, ZA_OFFSET_L_TC, data[5]);
+ // Output scaled accelerometer biases for manual subtraction in the main program
+ _accelBias[0] = (float)accelBias[0] / (float)accelSensitivity;
+ _accelBias[1] = (float)accelBias[1] / (float)accelSensitivity;
+ _accelBias[2] = (float)accelBias[2] / (float)accelSensitivity;
+}
+
+/**
+ * @brief Performs accelerometer and gyroscope self test
+ * @note Checks calibration wrt factory settings.
+ * Should return percent deviation from factory trim values
+ * +/- 14 or less deviation is a pass
+ * @param
+ * @retval true if passed
+ * false otherwise
+ */
+bool MPU6050::selfTestOK()
+{
+ uint8_t rawData[4] = { 0, 0, 0, 0 };
+ uint8_t selfTest[6];
+ float factoryTrim[6];
+ //
+ // Configure the accelerometer for self-test
+ writeReg(ACCEL_CONFIG, 0xF0); // Enable self test on all three axes and set accelerometer range to +/- 8 g
+ writeReg(GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
+#if MBED_MAJOR_VERSION > 5
+ ThisThread::sleep_for(250ms);
+#else
+ wait_ms(250);
+#endif
+ rawData[0] = readReg(SELF_TEST_X); // X-axis self-test results
+ rawData[1] = readReg(SELF_TEST_Y); // Y-axis self-test results
+ rawData[2] = readReg(SELF_TEST_Z); // Z-axis self-test results
+ rawData[3] = readReg(SELF_TEST_A); // Mixed-axis self-test results
+
+ // Extract the acceleration test results first
+ selfTest[0] = (rawData[0] >> 3) | (rawData[3] & 0x30) >> 4; // XA_TEST result is a five-bit unsigned integer
+ selfTest[1] = (rawData[1] >> 3) | (rawData[3] & 0x0C) >> 4; // YA_TEST result is a five-bit unsigned integer
+ selfTest[2] = (rawData[2] >> 3) | (rawData[3] & 0x03) >> 4; // ZA_TEST result is a five-bit unsigned integer
+
+ // Extract the gyration test results first
+ selfTest[3] = rawData[0] & 0x1F; // XG_TEST result is a five-bit unsigned integer
+ selfTest[4] = rawData[1] & 0x1F; // YG_TEST result is a five-bit unsigned integer
+ selfTest[5] = rawData[2] & 0x1F; // ZG_TEST result is a five-bit unsigned integer
+
+ // Process results to allow final comparison with factory set values
+ factoryTrim[0] = (4096.0f * 0.34f) * (pow((0.92f / 0.34f), ((selfTest[0] - 1.0f) / 30.0f))); // FT[Xa] factory trim calculation
+ factoryTrim[1] = (4096.0f * 0.34f) * (pow((0.92f / 0.34f), ((selfTest[1] - 1.0f) / 30.0f))); // FT[Ya] factory trim calculation
+ factoryTrim[2] = (4096.0f * 0.34f) * (pow((0.92f / 0.34f), ((selfTest[2] - 1.0f) / 30.0f))); // FT[Za] factory trim calculation
+ factoryTrim[3] = (25.0f * 131.0f) * (pow(1.046f, (selfTest[3] - 1.0f))); // FT[Xg] factory trim calculation
+ factoryTrim[4] = (-25.0f * 131.0f) * (pow(1.046f, (selfTest[4] - 1.0f))); // FT[Yg] factory trim calculation
+ factoryTrim[5] = (25.0f * 131.0f) * (pow(1.046f, (selfTest[5] - 1.0f))); // FT[Zg] factory trim calculation
+
+ // Output self-test results and factory trim calculation if desired
+ // Serial.println(selfTest[0]); Serial.println(selfTest[1]); Serial.println(selfTest[2]);
+ // Serial.println(selfTest[3]); Serial.println(selfTest[4]); Serial.println(selfTest[5]);
+ // Serial.println(factoryTrim[0]); Serial.println(factoryTrim[1]); Serial.println(factoryTrim[2]);
+ // Serial.println(factoryTrim[3]); Serial.println(factoryTrim[4]); Serial.println(factoryTrim[5]);
+ // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
+ // To get to percent, must multiply by 100 and subtract result from 100
+ for (int i = 0; i < 6; i++) {
+ _selfTest[i] = 100.0f + 100.0f * (selfTest[i] - factoryTrim[i]) / factoryTrim[i]; // Report percent differences
+ }
+
+ return
+ (
+ _selfTest[0] < 1.0f &&
+ _selfTest[1] < 1.0f &&
+ _selfTest[2] < 1.0f &&
+ _selfTest[3] < 1.0f &&
+ _selfTest[4] < 1.0f &&
+ _selfTest[5] < 1.0f
+ );
+}
+
+/**
+ * @brief Computes acceleration
+ * @note
+ * @param
+ * @retval
+ */
+float* MPU6050::accel()
+{
+ accelADC();
+
+ // Compute actual acceleration values, this depends on used scale
+ accelX = (float)_accelAdc[0] * _accelRes - _accelBias[0];
+ accelY = (float)_accelAdc[1] * _accelRes - _accelBias[1];
+ accelZ = (float)_accelAdc[2] * _accelRes - _accelBias[2];
+
+ return accelData;
+}
+
+/**
+ * @brief Computes gyro
+ * @note
+ * @param
+ * @retval
+ */
+float* MPU6050::gyro()
+{
+ gyroADC();
+
+ // Compute actual gyro values, this depends on used scale
+ gyroX = (float)_gyroAdc[0] * _gyroRes - _gyroBias[0];
+ gyroY = (float)_gyroAdc[1] * _gyroRes - _gyroBias[1];
+ gyroZ = (float)_gyroAdc[2] * _gyroRes - _gyroBias[2];
+ return gyroData;
+}
+
+/**
+ * @brief Adjusts filter gain after device is stabilized
+ * @note
+ * @param
+ * @retval
+ */
+void MPU6050::setGain(float beta, float zeta)
+{
+ _beta = beta; // set filter gain
+ _zeta = zeta; // set bias drift gain
+}
+
+/**
+ * @brief Madgwick filter
+ * @note Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
+ * (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
+ * which fuses acceleration and rotation rate to produce a quaternion-based estimate of relative
+ * device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
+ * The performance of the orientation filter is almost 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!
+ * @param deltaT Integration time in seconds.
+ * @retval
+ */
+void MPU6050::madgwickFilter(float deltaT)
+{
+ // aliases for better readability
+ float& q1 = _q[0];
+ float& q2 = _q[1];
+ float& q3 = _q[2];
+ float& q4 = _q[3];
+ float norm; // vector norm
+ float f1, f2, f3; // objective funcion elements
+ float j_11or24, j_12or23, j_13or22, j_14or21, j_32, j_33; // objective function Jacobian elements
+ float qDot1, qDot2, qDot3, qDot4;
+ float hatDot1, hatDot2, hatDot3, hatDot4;
+ float ax = accelX;
+ float ay = accelY;
+ float az = accelZ;
+ float gx = gyroX * M_PI / 180.0f; // convert to rad/s
+ float gy = gyroY * M_PI / 180.0f; // convert to rad/s
+ float gz = gyroZ * M_PI / 180.0f; // convert to rad/s
+ float gErrX, gErrY, gErrZ, gBiasX, gBiasY, gBiasZ; // gyro bias errors
+
+ // Auxiliary variables to avoid repeated arithmetic
+ float halfq1 = 0.5f * q1;
+ float halfq2 = 0.5f * q2;
+ float halfq3 = 0.5f * q3;
+ float halfq4 = 0.5f * q4;
+ 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;
+ // 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;
+
+ // Compute the objective function and Jacobian
+ f1 = _2q2 * q4 - _2q1 * q3 - ax;
+ f2 = _2q1 * q2 + _2q3 * q4 - ay;
+ f3 = 1.0f - _2q2 * q2 - _2q3 * q3 - az;
+ j_11or24 = _2q3;
+ j_12or23 = _2q4;
+ j_13or22 = _2q1;
+ j_14or21 = _2q2;
+ j_32 = 2.0f * j_14or21;
+ j_33 = 2.0f * j_11or24;
+
+ // Compute the gradient (matrix multiplication)
+ hatDot1 = j_14or21 * f2 - j_11or24 * f1;
+ hatDot2 = j_12or23 * f1 + j_13or22 * f2 - j_32 * f3;
+ hatDot3 = j_12or23 * f2 - j_33 * f3 - j_13or22 * f1;
+ hatDot4 = j_14or21 * f1 + j_11or24 * f2;
+
+ // Normalize the gradient
+ norm = sqrt(hatDot1 * hatDot1 + hatDot2 * hatDot2 + hatDot3 * hatDot3 + hatDot4 * hatDot4);
+ hatDot1 /= norm;
+ hatDot2 /= norm;
+ hatDot3 /= norm;
+ hatDot4 /= norm;
+
+ // Compute estimated gyroscope errors
+ gErrX = _2q1 * hatDot2 - _2q2 * hatDot1 - _2q3 * hatDot4 + _2q4 * hatDot3;
+ gErrY = _2q1 * hatDot3 + _2q2 * hatDot4 - _2q3 * hatDot1 - _2q4 * hatDot2;
+ gErrZ = _2q1 * hatDot4 - _2q2 * hatDot3 + _2q3 * hatDot2 - _2q4 * hatDot1;
+
+ // Compute gyroscope biases
+ gBiasX += gErrX * deltaT * _zeta;
+ gBiasY += gErrY * deltaT * _zeta;
+ gBiasZ += gErrZ * deltaT * _zeta;
+
+ // Remove gyroscope biases
+ gx -= gBiasX;
+ gy -= gBiasY;
+ gz -= gBiasZ;
+
+ // Compute the quaternion derivative
+ qDot1 = -halfq2 * gx - halfq3 * gy - halfq4 * gz;
+ qDot2 = halfq1 * gx + halfq3 * gz - halfq4 * gy;
+ qDot3 = halfq1 * gy - halfq2 * gz + halfq4 * gx;
+ qDot4 = halfq1 * gz + halfq2 * gy - halfq3 * gx;
+
+ // Compute the integrated estimated quaternion derivative
+ q1 += (qDot1 - (_beta * hatDot1)) * deltaT;
+ q2 += (qDot2 - (_beta * hatDot2)) * deltaT;
+ q3 += (qDot3 - (_beta * hatDot3)) * deltaT;
+ q4 += (qDot4 - (_beta * hatDot4)) * deltaT;
+
+ // Normalize the quaternion
+ 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;
+}
+
+/**
+ * @brief Calculates yaw in degree
+ * @note
+ * @param
+ * @retval
+ */
+float MPU6050::yaw()
+{
+ float yawRad = 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]
+ );
+
+ return yawRad * 180.f / M_PI;
+}
+
+/**
+ * @brief Calculates pitch in degree
+ * @note
+ * @param
+ * @retval
+ */
+float MPU6050::pitch()
+{
+ float pitchRad = -asin(2.0f * (_q[1] * _q[3] - _q[0] * _q[2]));
+
+ return pitchRad * 180.f / M_PI;
+}
+
+/**
+ * @brief Claculates roll in degree
+ * @note
+ * @param
+ * @retval
+ */
+float MPU6050::roll()
+{
+ float rollRad = 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]
+ );
+
+ return rollRad * 180.0f / M_PI;
+}
diff -r 000000000000 -r 9c2bb0f94c31 MPU6050.h
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MPU6050.h Mon Jan 18 19:44:43 2021 +0000
@@ -0,0 +1,240 @@
+#ifndef MPU6050_H
+#define MPU6050_H
+
+#include "mbed.h"
+#include "math.h"
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+// Define registers per MPU6050, Register Map and Descriptions, Rev 4.2, 08/19/2013 6 DOF Motion sensor fusion device
+
+// Invensense Inc., www.invensense.com
+// See also MPU-6050 Register Map and Descriptions, Revision 4.0, RM-MPU-6050A-00, 9/12/2012 for registers not listed in
+// above document; the MPU6050 and MPU 9150 are virtually identical but the latter has an on-board magnetic sensor
+//
+#define XGOFFS_TC 0x00 // Bit 7 PWR_MODE, bits 6:1 XG_OFFS_TC, bit 0 OTP_BNK_VLD
+#define YGOFFS_TC 0x01
+#define ZGOFFS_TC 0x02
+#define X_FINE_GAIN 0x03 // [7:0] fine gain
+#define Y_FINE_GAIN 0x04
+#define Z_FINE_GAIN 0x05
+#define XA_OFFSET_H 0x06 // User-defined trim values for accelerometer
+#define XA_OFFSET_L_TC 0x07
+#define YA_OFFSET_H 0x08
+#define YA_OFFSET_L_TC 0x09
+#define ZA_OFFSET_H 0x0A
+#define ZA_OFFSET_L_TC 0x0B
+#define SELF_TEST_X 0x0D
+#define SELF_TEST_Y 0x0E
+#define SELF_TEST_Z 0x0F
+#define SELF_TEST_A 0x10
+#define XG_OFFS_USRH 0x13 // User-defined trim values for gyroscope; supported in MPU-6050?
+#define XG_OFFS_USRL 0x14
+#define YG_OFFS_USRH 0x15
+#define YG_OFFS_USRL 0x16
+#define ZG_OFFS_USRH 0x17
+#define ZG_OFFS_USRL 0x18
+#define SMPLRT_DIV 0x19
+#define CONFIG 0x1A
+#define GYRO_CONFIG 0x1B
+#define ACCEL_CONFIG 0x1C
+#define FF_THR 0x1D // Free-fall
+#define FF_DUR 0x1E // Free-fall
+#define MOT_THR 0x1F // Motion detection threshold bits [7:0]
+#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_SLV0_ADDR 0x25
+#define I2C_SLV0_REG 0x26
+#define I2C_SLV0_CTRL 0x27
+#define I2C_SLV1_ADDR 0x28
+#define I2C_SLV1_REG 0x29
+#define I2C_SLV1_CTRL 0x2A
+#define I2C_SLV2_ADDR 0x2B
+#define I2C_SLV2_REG 0x2C
+#define I2C_SLV2_CTRL 0x2D
+#define I2C_SLV3_ADDR 0x2E
+#define I2C_SLV3_REG 0x2F
+#define I2C_SLV3_CTRL 0x30
+#define I2C_SLV4_ADDR 0x31
+#define I2C_SLV4_REG 0x32
+#define I2C_SLV4_DO 0x33
+#define I2C_SLV4_CTRL 0x34
+#define I2C_SLV4_DI 0x35
+#define I2C_MST_STATUS 0x36
+#define INT_PIN_CFG 0x37
+#define INT_ENABLE 0x38
+#define DMP_INT_STATUS 0x39 // Check DMP interrupt
+#define INT_STATUS 0x3A
+#define ACCEL_XOUT_H 0x3B
+#define ACCEL_XOUT_L 0x3C
+#define ACCEL_YOUT_H 0x3D
+#define ACCEL_YOUT_L 0x3E
+#define ACCEL_ZOUT_H 0x3F
+#define ACCEL_ZOUT_L 0x40
+#define TEMP_OUT_H 0x41
+#define TEMP_OUT_L 0x42
+#define GYRO_XOUT_H 0x43
+#define GYRO_XOUT_L 0x44
+#define GYRO_YOUT_H 0x45
+#define GYRO_YOUT_L 0x46
+#define GYRO_ZOUT_H 0x47
+#define GYRO_ZOUT_L 0x48
+#define EXT_SENS_DATA_00 0x49
+#define EXT_SENS_DATA_01 0x4A
+#define EXT_SENS_DATA_02 0x4B
+#define EXT_SENS_DATA_03 0x4C
+#define EXT_SENS_DATA_04 0x4D
+#define EXT_SENS_DATA_05 0x4E
+#define EXT_SENS_DATA_06 0x4F
+#define EXT_SENS_DATA_07 0x50
+#define EXT_SENS_DATA_08 0x51
+#define EXT_SENS_DATA_09 0x52
+#define EXT_SENS_DATA_10 0x53
+#define EXT_SENS_DATA_11 0x54
+#define EXT_SENS_DATA_12 0x55
+#define EXT_SENS_DATA_13 0x56
+#define EXT_SENS_DATA_14 0x57
+#define EXT_SENS_DATA_15 0x58
+#define EXT_SENS_DATA_16 0x59
+#define EXT_SENS_DATA_17 0x5A
+#define EXT_SENS_DATA_18 0x5B
+#define EXT_SENS_DATA_19 0x5C
+#define EXT_SENS_DATA_20 0x5D
+#define EXT_SENS_DATA_21 0x5E
+#define EXT_SENS_DATA_22 0x5F
+#define EXT_SENS_DATA_23 0x60
+#define MOT_DETECT_STATUS 0x61
+#define I2C_SLV0_DO 0x63
+#define I2C_SLV1_DO 0x64
+#define I2C_SLV2_DO 0x65
+#define I2C_SLV3_DO 0x66
+#define I2C_MST_DELAY_CTRL 0x67
+#define SIGNAL_PATH_RESET 0x68
+#define MOT_DETECT_CTRL 0x69
+#define USER_CTRL 0x6A // Bit 7 enable DMP, bit 3 reset DMP
+#define PWR_MGMT_1 0x6B // Device defaults to the SLEEP mode
+#define PWR_MGMT_2 0x6C
+#define DMP_BANK 0x6D // Activates a specific bank in the DMP
+#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 FIFO_COUNTH 0x72
+#define FIFO_COUNTL 0x73
+#define FIFO_R_W 0x74
+#define WHO_AM_I_MPU6050 0x75 // Should return 0x68
+
+// Register bits
+#define DATA_RDY_INT 0
+#define I2C_MST_EN 5
+
+enum AccelScale
+{
+ AFS_2G,
+ AFS_4G,
+ AFS_8G,
+ AFS_16G
+};
+
+enum GyroScale
+{
+ GFS_250DPS,
+ GFS_500DPS,
+ GFS_1000DPS,
+ GFS_2000DPS
+};
+
+class MPU6050
+{
+ uint8_t _addr;
+ AccelScale _accelScale;
+ GyroScale _gyroScale;
+ I2C _i2c;
+ InterruptIn _interruptIn;
+ float _accelRes;
+ float _gyroRes;
+ int16_t _accelAdc[3]; // Stores the 16-bit signed accelerometer sensor output
+ int16_t _gyroAdc[3]; // Stores the 16-bit signed gyro sensor output
+ float _gyroBias[3] = { 0 };
+ float _accelBias[3] = { 0 }; // Bias corrections for gyro and accelerometer
+ int16_t _tempInt; // Stores the real internal chip temperature in degrees Celsius
+ float _temp;
+ float _selfTest[6];
+
+ // parameters for 6 DoF sensor fusion calculations
+ const float _gyroError = M_PI * (40.0f / 180.0f); // gyroscope measurement error in rads/s (start at 60 deg/s), then reduce after ~10 s to 3
+ const float _gyroDrift = M_PI * (2.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
+ float _beta; // compute beta
+ float _zeta; // compute zeta, the other free parameter in the Madgwick scheme usually set to a small or zero value
+ float _pitch, _yaw, _roll;
+ float _q[4] = { 1.0f, 0.0f, 0.0f, 0.0f }; // vector to hold quaternion
+ void writeReg(uint8_t reg, uint8_t byte);
+ uint8_t readReg(uint8_t reg);
+ void readRegBytes(uint8_t reg, uint8_t len, uint8_t* dest);
+ int16_t* accelADC();
+ int16_t* gyroADC();
+ int16_t tempADC();
+public:
+ float accelData[3]; // Stores the real accelerometer sensor output
+ float& accelX = accelData[0]; // Acceleration liases
+ float& accelY = accelData[1];
+ float& accelZ = accelData[2];
+ float gyroData[3]; // Stores the real gyro sensor output
+ float& gyroX = gyroData[0]; // Gyro aliases
+ float& gyroY = gyroData[1];
+ float& gyroZ = gyroData[2];
+
+ MPU6050
+ (
+ uint8_t addr = 0x68,
+ AccelScale accelScale = AFS_2G,
+ GyroScale gyroScale = GFS_250DPS,
+ PinName sdaPin = I2C_SDA,
+ PinName sclPin = I2C_SCL,
+ PinName interruptInPin = NC
+ );
+ virtual ~MPU6050() { }
+ void rise(Callback<void (void)> func);
+ template<typename T>
+ void rise(T* tptr, void (T:: *mptr) (void));
+ void fall(Callback<void (void)> func);
+ template<typename T>
+ void fall(T* tptr, void (T:: *mptr) (void));
+ bool init();
+ bool dataReady();
+ float* accel();
+ float* gyro();
+ float temp();
+
+ // Configure the motion detection control for low power accelerometer mode
+ void lowPowerAccelOnly();
+ void reset();
+
+ // 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 calibrate();
+
+ // Accelerometer and gyroscope self test; check calibration wrt factory settings
+ bool selfTestOK(); // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
+ void setGain(float beta, float zeta);
+
+ // Implementation of Sebastian Madgwick's "...efficient orientation filter for inertial/magnetic sensor arrays"
+ // (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
+ // which fuses acceleration and rotation rate to produce a quaternion-based estimate of relative
+ // device orientation -- which can be converted to yaw, pitch, and roll.
+ // Useful for stabilizing quadcopters, etc.
+ // The performance of the orientation filter is almost 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 madgwickFilter(float deltaT);
+
+ // To compute yaw, pitch and roll after after aplying the madgwickFilter
+ float yaw();
+ float pitch();
+ float roll();
+};
+#endif // MPU6050_H