tom dunigan
/
mpu9250
MPU9250 test with polling or ISR
main.cpp@0:31cc139b7d1e, 2016-09-10 (annotated)
- Committer:
- manitou
- Date:
- Sat Sep 10 14:15:19 2016 +0000
- Revision:
- 0:31cc139b7d1e
- Child:
- 1:0158e4d78423
MPU9250 test polling or ISR
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
manitou | 0:31cc139b7d1e | 1 | /* MPU9250 Basic Example Code |
manitou | 0:31cc139b7d1e | 2 | by: Kris Winer |
manitou | 0:31cc139b7d1e | 3 | date: April 1, 2014 |
manitou | 0:31cc139b7d1e | 4 | license: Beerware - Use this code however you'd like. If you |
manitou | 0:31cc139b7d1e | 5 | find it useful you can buy me a beer some time. |
manitou | 0:31cc139b7d1e | 6 | |
manitou | 0:31cc139b7d1e | 7 | Demonstrate basic MPU-9250 functionality including parameterizing the register addresses, initializing the sensor, |
manitou | 0:31cc139b7d1e | 8 | getting properly scaled accelerometer, gyroscope, and magnetometer data out. Added display functions to |
manitou | 0:31cc139b7d1e | 9 | allow display to on breadboard monitor. Addition of 9 DoF sensor fusion using open source Madgwick and |
manitou | 0:31cc139b7d1e | 10 | Mahony filter algorithms. Sketch runs on the 3.3 V 8 MHz Pro Mini and the Teensy 3.1. |
manitou | 0:31cc139b7d1e | 11 | |
manitou | 0:31cc139b7d1e | 12 | SDA and SCL should have external pull-up resistors (to 3.3V). |
manitou | 0:31cc139b7d1e | 13 | 10k resistors are on the EMSENSR-9250 breakout board. |
manitou | 0:31cc139b7d1e | 14 | |
manitou | 0:31cc139b7d1e | 15 | Hardware setup: |
manitou | 0:31cc139b7d1e | 16 | MPU9250 Breakout --------- Arduino |
manitou | 0:31cc139b7d1e | 17 | VDD ---------------------- 3.3V |
manitou | 0:31cc139b7d1e | 18 | VDDI --------------------- 3.3V |
manitou | 0:31cc139b7d1e | 19 | SDA ----------------------- A4 |
manitou | 0:31cc139b7d1e | 20 | SCL ----------------------- A5 |
manitou | 0:31cc139b7d1e | 21 | GND ---------------------- GND |
manitou | 0:31cc139b7d1e | 22 | |
manitou | 0:31cc139b7d1e | 23 | Note: The MPU9250 is an I2C sensor and uses the Arduino Wire library. |
manitou | 0:31cc139b7d1e | 24 | 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. |
manitou | 0:31cc139b7d1e | 25 | We have disabled the internal pull-ups used by the Wire library in the Wire.h/twi.c utility file. |
manitou | 0:31cc139b7d1e | 26 | We are also using the 400 kHz fast I2C mode by setting the TWI_FREQ to 400000L /twi.h utility file. |
manitou | 0:31cc139b7d1e | 27 | */ |
manitou | 0:31cc139b7d1e | 28 | |
manitou | 0:31cc139b7d1e | 29 | //#include "ST_F401_84MHZ.h" |
manitou | 0:31cc139b7d1e | 30 | //F401_init84 myinit(0); |
manitou | 0:31cc139b7d1e | 31 | #include "mbed.h" |
manitou | 0:31cc139b7d1e | 32 | #include "MPU9250.h" |
manitou | 0:31cc139b7d1e | 33 | |
manitou | 0:31cc139b7d1e | 34 | |
manitou | 0:31cc139b7d1e | 35 | float sum = 0; |
manitou | 0:31cc139b7d1e | 36 | uint32_t sumCount = 0; |
manitou | 0:31cc139b7d1e | 37 | |
manitou | 0:31cc139b7d1e | 38 | MPU9250 mpu9250; |
manitou | 0:31cc139b7d1e | 39 | |
manitou | 0:31cc139b7d1e | 40 | Timer t; |
manitou | 0:31cc139b7d1e | 41 | |
manitou | 0:31cc139b7d1e | 42 | Serial pc(USBTX, USBRX); // tx, rx |
manitou | 0:31cc139b7d1e | 43 | |
manitou | 0:31cc139b7d1e | 44 | volatile bool newData = false; |
manitou | 0:31cc139b7d1e | 45 | |
manitou | 0:31cc139b7d1e | 46 | InterruptIn isrPin(D12); //k64 D12 dragon PD_0 |
manitou | 0:31cc139b7d1e | 47 | |
manitou | 0:31cc139b7d1e | 48 | void mpuisr() { |
manitou | 0:31cc139b7d1e | 49 | newData=true; |
manitou | 0:31cc139b7d1e | 50 | } |
manitou | 0:31cc139b7d1e | 51 | |
manitou | 0:31cc139b7d1e | 52 | int main() |
manitou | 0:31cc139b7d1e | 53 | { |
manitou | 0:31cc139b7d1e | 54 | pc.baud(9600); |
manitou | 0:31cc139b7d1e | 55 | |
manitou | 0:31cc139b7d1e | 56 | //Set up I2C |
manitou | 0:31cc139b7d1e | 57 | i2c.frequency(400000); // use fast (400 kHz) I2C |
manitou | 0:31cc139b7d1e | 58 | |
manitou | 0:31cc139b7d1e | 59 | pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock); |
manitou | 0:31cc139b7d1e | 60 | |
manitou | 0:31cc139b7d1e | 61 | t.start(); |
manitou | 0:31cc139b7d1e | 62 | isrPin.rise(&mpuisr); |
manitou | 0:31cc139b7d1e | 63 | |
manitou | 0:31cc139b7d1e | 64 | // Read the WHO_AM_I register, this is a good test of communication |
manitou | 0:31cc139b7d1e | 65 | uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250); // Read WHO_AM_I register for MPU-9250 |
manitou | 0:31cc139b7d1e | 66 | pc.printf("I AM 0x%x\n\r", whoami); pc.printf("I SHOULD BE 0x71\n\r"); |
manitou | 0:31cc139b7d1e | 67 | |
manitou | 0:31cc139b7d1e | 68 | if (whoami == 0x71) // WHO_AM_I should always be 0x68 |
manitou | 0:31cc139b7d1e | 69 | { |
manitou | 0:31cc139b7d1e | 70 | pc.printf("MPU9250 is online...\n\r"); |
manitou | 0:31cc139b7d1e | 71 | wait(1); |
manitou | 0:31cc139b7d1e | 72 | |
manitou | 0:31cc139b7d1e | 73 | |
manitou | 0:31cc139b7d1e | 74 | mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration |
manitou | 0:31cc139b7d1e | 75 | mpu9250.calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers |
manitou | 0:31cc139b7d1e | 76 | pc.printf("x gyro bias = %f\n\r", gyroBias[0]); |
manitou | 0:31cc139b7d1e | 77 | pc.printf("y gyro bias = %f\n\r", gyroBias[1]); |
manitou | 0:31cc139b7d1e | 78 | pc.printf("z gyro bias = %f\n\r", gyroBias[2]); |
manitou | 0:31cc139b7d1e | 79 | pc.printf("x accel bias = %f\n\r", accelBias[0]); |
manitou | 0:31cc139b7d1e | 80 | pc.printf("y accel bias = %f\n\r", accelBias[1]); |
manitou | 0:31cc139b7d1e | 81 | pc.printf("z accel bias = %f\n\r", accelBias[2]); |
manitou | 0:31cc139b7d1e | 82 | wait(2); |
manitou | 0:31cc139b7d1e | 83 | mpu9250.initMPU9250(); |
manitou | 0:31cc139b7d1e | 84 | pc.printf("MPU9250 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature |
manitou | 0:31cc139b7d1e | 85 | mpu9250.initAK8963(magCalibration); |
manitou | 0:31cc139b7d1e | 86 | pc.printf("AK8963 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer |
manitou | 0:31cc139b7d1e | 87 | pc.printf("Accelerometer full-scale range = %f g\n\r", 2.0f*(float)(1<<Ascale)); |
manitou | 0:31cc139b7d1e | 88 | pc.printf("Gyroscope full-scale range = %f deg/s\n\r", 250.0f*(float)(1<<Gscale)); |
manitou | 0:31cc139b7d1e | 89 | if(Mscale == 0) pc.printf("Magnetometer resolution = 14 bits\n\r"); |
manitou | 0:31cc139b7d1e | 90 | if(Mscale == 1) pc.printf("Magnetometer resolution = 16 bits\n\r"); |
manitou | 0:31cc139b7d1e | 91 | if(Mmode == 2) pc.printf("Magnetometer ODR = 8 Hz\n\r"); |
manitou | 0:31cc139b7d1e | 92 | if(Mmode == 6) pc.printf("Magnetometer ODR = 100 Hz\n\r"); |
manitou | 0:31cc139b7d1e | 93 | wait(2); |
manitou | 0:31cc139b7d1e | 94 | } |
manitou | 0:31cc139b7d1e | 95 | else |
manitou | 0:31cc139b7d1e | 96 | { |
manitou | 0:31cc139b7d1e | 97 | pc.printf("Could not connect to MPU9250: \n\r"); |
manitou | 0:31cc139b7d1e | 98 | pc.printf("%#x \n", whoami); |
manitou | 0:31cc139b7d1e | 99 | |
manitou | 0:31cc139b7d1e | 100 | |
manitou | 0:31cc139b7d1e | 101 | while(1) ; // Loop forever if communication doesn't happen |
manitou | 0:31cc139b7d1e | 102 | } |
manitou | 0:31cc139b7d1e | 103 | |
manitou | 0:31cc139b7d1e | 104 | mpu9250.getAres(); // Get accelerometer sensitivity |
manitou | 0:31cc139b7d1e | 105 | mpu9250.getGres(); // Get gyro sensitivity |
manitou | 0:31cc139b7d1e | 106 | mpu9250.getMres(); // Get magnetometer sensitivity |
manitou | 0:31cc139b7d1e | 107 | pc.printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/aRes); |
manitou | 0:31cc139b7d1e | 108 | pc.printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/gRes); |
manitou | 0:31cc139b7d1e | 109 | pc.printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mRes); |
manitou | 0:31cc139b7d1e | 110 | magbias[0] = +470.; // User environmental x-axis correction in milliGauss, should be automatically calculated |
manitou | 0:31cc139b7d1e | 111 | magbias[1] = +120.; // User environmental x-axis correction in milliGauss |
manitou | 0:31cc139b7d1e | 112 | magbias[2] = +125.; // User environmental x-axis correction in milliGauss |
manitou | 0:31cc139b7d1e | 113 | |
manitou | 0:31cc139b7d1e | 114 | while(1) { |
manitou | 0:31cc139b7d1e | 115 | static int readycnt=0; |
manitou | 0:31cc139b7d1e | 116 | // If intPin goes high, all data registers have new data |
manitou | 0:31cc139b7d1e | 117 | |
manitou | 0:31cc139b7d1e | 118 | #if USE_ISR |
manitou | 0:31cc139b7d1e | 119 | if(newData) { |
manitou | 0:31cc139b7d1e | 120 | newData=false; |
manitou | 0:31cc139b7d1e | 121 | mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS); //? need this with ISR |
manitou | 0:31cc139b7d1e | 122 | #else |
manitou | 0:31cc139b7d1e | 123 | if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) { // On interrupt, check if data ready interrupt |
manitou | 0:31cc139b7d1e | 124 | #endif |
manitou | 0:31cc139b7d1e | 125 | readycnt++; |
manitou | 0:31cc139b7d1e | 126 | mpu9250.readAccelData(accelCount); // Read the x/y/z adc values |
manitou | 0:31cc139b7d1e | 127 | // Now we'll calculate the accleration value into actual g's |
manitou | 0:31cc139b7d1e | 128 | ax = (float)accelCount[0]*aRes - accelBias[0]; // get actual g value, this depends on scale being set |
manitou | 0:31cc139b7d1e | 129 | ay = (float)accelCount[1]*aRes - accelBias[1]; |
manitou | 0:31cc139b7d1e | 130 | az = (float)accelCount[2]*aRes - accelBias[2]; |
manitou | 0:31cc139b7d1e | 131 | |
manitou | 0:31cc139b7d1e | 132 | mpu9250.readGyroData(gyroCount); // Read the x/y/z adc values |
manitou | 0:31cc139b7d1e | 133 | // Calculate the gyro value into actual degrees per second |
manitou | 0:31cc139b7d1e | 134 | gx = (float)gyroCount[0]*gRes - gyroBias[0]; // get actual gyro value, this depends on scale being set |
manitou | 0:31cc139b7d1e | 135 | gy = (float)gyroCount[1]*gRes - gyroBias[1]; |
manitou | 0:31cc139b7d1e | 136 | gz = (float)gyroCount[2]*gRes - gyroBias[2]; |
manitou | 0:31cc139b7d1e | 137 | |
manitou | 0:31cc139b7d1e | 138 | mpu9250.readMagData(magCount); // Read the x/y/z adc values |
manitou | 0:31cc139b7d1e | 139 | // Calculate the magnetometer values in milliGauss |
manitou | 0:31cc139b7d1e | 140 | // Include factory calibration per data sheet and user environmental corrections |
manitou | 0:31cc139b7d1e | 141 | mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0]; // get actual magnetometer value, this depends on scale being set |
manitou | 0:31cc139b7d1e | 142 | my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1]; |
manitou | 0:31cc139b7d1e | 143 | mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2]; |
manitou | 0:31cc139b7d1e | 144 | } |
manitou | 0:31cc139b7d1e | 145 | |
manitou | 0:31cc139b7d1e | 146 | Now = t.read_us(); |
manitou | 0:31cc139b7d1e | 147 | deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update |
manitou | 0:31cc139b7d1e | 148 | lastUpdate = Now; |
manitou | 0:31cc139b7d1e | 149 | |
manitou | 0:31cc139b7d1e | 150 | sum += deltat; |
manitou | 0:31cc139b7d1e | 151 | sumCount++; |
manitou | 0:31cc139b7d1e | 152 | |
manitou | 0:31cc139b7d1e | 153 | // if(lastUpdate - firstUpdate > 10000000.0f) { |
manitou | 0:31cc139b7d1e | 154 | // beta = 0.04; // decrease filter gain after stabilized |
manitou | 0:31cc139b7d1e | 155 | // zeta = 0.015; // increasey bias drift gain after stabilized |
manitou | 0:31cc139b7d1e | 156 | // } |
manitou | 0:31cc139b7d1e | 157 | |
manitou | 0:31cc139b7d1e | 158 | // Pass gyro rate as rad/s |
manitou | 0:31cc139b7d1e | 159 | uint32_t us = t.read_us(); |
manitou | 0:31cc139b7d1e | 160 | mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz); |
manitou | 0:31cc139b7d1e | 161 | us = t.read_us()-us; |
manitou | 0:31cc139b7d1e | 162 | // mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz); |
manitou | 0:31cc139b7d1e | 163 | |
manitou | 0:31cc139b7d1e | 164 | // Serial print and/or display at 0.5 s rate independent of data rates |
manitou | 0:31cc139b7d1e | 165 | delt_t = t.read_ms() - count; |
manitou | 0:31cc139b7d1e | 166 | if (delt_t > 500) { // update LCD once per half-second independent of read rate |
manitou | 0:31cc139b7d1e | 167 | pc.printf("readycnt %d us %d\n",readycnt,us); |
manitou | 0:31cc139b7d1e | 168 | readycnt=0; |
manitou | 0:31cc139b7d1e | 169 | pc.printf("ax = %f", 1000*ax); |
manitou | 0:31cc139b7d1e | 170 | pc.printf(" ay = %f", 1000*ay); |
manitou | 0:31cc139b7d1e | 171 | pc.printf(" az = %f mg\n\r", 1000*az); |
manitou | 0:31cc139b7d1e | 172 | |
manitou | 0:31cc139b7d1e | 173 | pc.printf("gx = %f", gx); |
manitou | 0:31cc139b7d1e | 174 | pc.printf(" gy = %f", gy); |
manitou | 0:31cc139b7d1e | 175 | pc.printf(" gz = %f deg/s\n\r", gz); |
manitou | 0:31cc139b7d1e | 176 | |
manitou | 0:31cc139b7d1e | 177 | pc.printf("gx = %f", mx); |
manitou | 0:31cc139b7d1e | 178 | pc.printf(" gy = %f", my); |
manitou | 0:31cc139b7d1e | 179 | pc.printf(" gz = %f mG\n\r", mz); |
manitou | 0:31cc139b7d1e | 180 | |
manitou | 0:31cc139b7d1e | 181 | tempCount = mpu9250.readTempData(); // Read the adc values |
manitou | 0:31cc139b7d1e | 182 | temperature = ((float) tempCount) / 333.87f + 21.0f; // Temperature in degrees Centigrade |
manitou | 0:31cc139b7d1e | 183 | pc.printf("temperature = %f C\n\r", temperature); |
manitou | 0:31cc139b7d1e | 184 | |
manitou | 0:31cc139b7d1e | 185 | pc.printf("q0 = %f\n\r", q[0]); |
manitou | 0:31cc139b7d1e | 186 | pc.printf("q1 = %f\n\r", q[1]); |
manitou | 0:31cc139b7d1e | 187 | pc.printf("q2 = %f\n\r", q[2]); |
manitou | 0:31cc139b7d1e | 188 | pc.printf("q3 = %f\n\r", q[3]); |
manitou | 0:31cc139b7d1e | 189 | |
manitou | 0:31cc139b7d1e | 190 | |
manitou | 0:31cc139b7d1e | 191 | |
manitou | 0:31cc139b7d1e | 192 | // Define output variables from updated quaternion---these are Tait-Bryan angles, commonly used in aircraft orientation. |
manitou | 0:31cc139b7d1e | 193 | // In this coordinate system, the positive z-axis is down toward Earth. |
manitou | 0:31cc139b7d1e | 194 | // 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. |
manitou | 0:31cc139b7d1e | 195 | // Pitch is angle between sensor x-axis and Earth ground plane, toward the Earth is positive, up toward the sky is negative. |
manitou | 0:31cc139b7d1e | 196 | // Roll is angle between sensor y-axis and Earth ground plane, y-axis up is positive roll. |
manitou | 0:31cc139b7d1e | 197 | // These arise from the definition of the homogeneous rotation matrix constructed from quaternions. |
manitou | 0:31cc139b7d1e | 198 | // Tait-Bryan angles as well as Euler angles are non-commutative; that is, the get the correct orientation the rotations must be |
manitou | 0:31cc139b7d1e | 199 | // applied in the correct order which for this configuration is yaw, pitch, and then roll. |
manitou | 0:31cc139b7d1e | 200 | // For more see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles which has additional links. |
manitou | 0:31cc139b7d1e | 201 | 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]); |
manitou | 0:31cc139b7d1e | 202 | pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2])); |
manitou | 0:31cc139b7d1e | 203 | 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]); |
manitou | 0:31cc139b7d1e | 204 | pitch *= 180.0f / PI; |
manitou | 0:31cc139b7d1e | 205 | yaw *= 180.0f / PI; |
manitou | 0:31cc139b7d1e | 206 | yaw -= 13.8f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04 |
manitou | 0:31cc139b7d1e | 207 | roll *= 180.0f / PI; |
manitou | 0:31cc139b7d1e | 208 | |
manitou | 0:31cc139b7d1e | 209 | pc.printf("Yaw, Pitch, Roll: %f %f %f\n\r", yaw, pitch, roll); |
manitou | 0:31cc139b7d1e | 210 | pc.printf("average rate = %f\n\r", (float) sumCount/sum); |
manitou | 0:31cc139b7d1e | 211 | |
manitou | 0:31cc139b7d1e | 212 | myled= !myled; |
manitou | 0:31cc139b7d1e | 213 | count = t.read_ms(); |
manitou | 0:31cc139b7d1e | 214 | sum = 0; |
manitou | 0:31cc139b7d1e | 215 | sumCount = 0; |
manitou | 0:31cc139b7d1e | 216 | } |
manitou | 0:31cc139b7d1e | 217 | } |
manitou | 0:31cc139b7d1e | 218 | |
manitou | 0:31cc139b7d1e | 219 | } |