Justin Bieber / Mbed 2 deprecated mpu9250bam

bamlor

Dependencies:   mbed

main.cpp@0:d52e8eda04c3, 2017-12-09 (annotated)

Committer:
jaybehandsome
Date:
Sat Dec 09 09:47:31 2017 +0000
Revision:
0:d52e8eda04c3
yeah;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jaybehandsome 0:d52e8eda04c3 1 /* MPU9250 Basic Example Code
jaybehandsome 0:d52e8eda04c3 2 by: Kris Winer
jaybehandsome 0:d52e8eda04c3 3 date: April 1, 2014
jaybehandsome 0:d52e8eda04c3 4 license: Beerware - Use this code however you'd like. If you
jaybehandsome 0:d52e8eda04c3 5 find it useful you can buy me a beer some time.
jaybehandsome 0:d52e8eda04c3 6
jaybehandsome 0:d52e8eda04c3 7 Demonstrate basic MPU-9250 functionality including parameterizing the register addresses, initializing the sensor,
jaybehandsome 0:d52e8eda04c3 8 getting properly scaled accelerometer, gyroscope, and magnetometer data out. Added display functions to
jaybehandsome 0:d52e8eda04c3 9 allow display to on breadboard monitor. Addition of 9 DoF sensor fusion using open source Madgwick and
jaybehandsome 0:d52e8eda04c3 10 Mahony filter algorithms. Sketch runs on the 3.3 V 8 MHz Pro Mini and the Teensy 3.1.
jaybehandsome 0:d52e8eda04c3 11
jaybehandsome 0:d52e8eda04c3 12 SDA and SCL should have external pull-up resistors (to 3.3V).
jaybehandsome 0:d52e8eda04c3 13 10k resistors are on the EMSENSR-9250 breakout board.
jaybehandsome 0:d52e8eda04c3 14
jaybehandsome 0:d52e8eda04c3 15 Hardware setup:
jaybehandsome 0:d52e8eda04c3 16 MPU9250 Breakout --------- Arduino
jaybehandsome 0:d52e8eda04c3 17 VDD ---------------------- 3.3V
jaybehandsome 0:d52e8eda04c3 18 VDDI --------------------- 3.3V
jaybehandsome 0:d52e8eda04c3 19 SDA ----------------------- A4
jaybehandsome 0:d52e8eda04c3 20 SCL ----------------------- A5
jaybehandsome 0:d52e8eda04c3 21 GND ---------------------- GND
jaybehandsome 0:d52e8eda04c3 22
jaybehandsome 0:d52e8eda04c3 23 Note: The MPU9250 is an I2C sensor and uses the Arduino Wire library.
jaybehandsome 0:d52e8eda04c3 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.
jaybehandsome 0:d52e8eda04c3 25 We have disabled the internal pull-ups used by the Wire library in the Wire.h/twi.c utility file.
jaybehandsome 0:d52e8eda04c3 26 We are also using the 400 kHz fast I2C mode by setting the TWI_FREQ to 400000L /twi.h utility file.
jaybehandsome 0:d52e8eda04c3 27 */
jaybehandsome 0:d52e8eda04c3 28
jaybehandsome 0:d52e8eda04c3 29 //#include "ST_F401_84MHZ.h"
jaybehandsome 0:d52e8eda04c3 30 //F401_init84 myinit(0);
jaybehandsome 0:d52e8eda04c3 31 #include "mbed.h"
jaybehandsome 0:d52e8eda04c3 32 #include "MPU9250.h"
jaybehandsome 0:d52e8eda04c3 33
jaybehandsome 0:d52e8eda04c3 34 // Using NOKIA 5110 monochrome 84 x 48 pixel display
jaybehandsome 0:d52e8eda04c3 35 // pin 9 - Serial clock out (SCLK)
jaybehandsome 0:d52e8eda04c3 36 // pin 8 - Serial data out (DIN)
jaybehandsome 0:d52e8eda04c3 37 // pin 7 - Data/Command select (D/C)
jaybehandsome 0:d52e8eda04c3 38 // pin 5 - LCD chip select (CS)
jaybehandsome 0:d52e8eda04c3 39 // pin 6 - LCD reset (RST)
jaybehandsome 0:d52e8eda04c3 40 //Adafruit_PCD8544 display = Adafruit_PCD8544(9, 8, 7, 5, 6);
jaybehandsome 0:d52e8eda04c3 41
jaybehandsome 0:d52e8eda04c3 42 float sum = 0;
jaybehandsome 0:d52e8eda04c3 43 uint32_t sumCount = 0;
jaybehandsome 0:d52e8eda04c3 44 char buffer[14];
jaybehandsome 0:d52e8eda04c3 45
jaybehandsome 0:d52e8eda04c3 46 MPU9250 mpu9250;
jaybehandsome 0:d52e8eda04c3 47
jaybehandsome 0:d52e8eda04c3 48 Timer t;
jaybehandsome 0:d52e8eda04c3 49
jaybehandsome 0:d52e8eda04c3 50 Serial pc(USBTX, USBRX); // tx, rx
jaybehandsome 0:d52e8eda04c3 51
jaybehandsome 0:d52e8eda04c3 52 // VCC, SCE, RST, D/C, MOSI,S CLK, LED
jaybehandsome 0:d52e8eda04c3 53
jaybehandsome 0:d52e8eda04c3 54
jaybehandsome 0:d52e8eda04c3 55
jaybehandsome 0:d52e8eda04c3 56
jaybehandsome 0:d52e8eda04c3 57 int main()
jaybehandsome 0:d52e8eda04c3 58 {
jaybehandsome 0:d52e8eda04c3 59 pc.baud(9600);
jaybehandsome 0:d52e8eda04c3 60
jaybehandsome 0:d52e8eda04c3 61 //Set up I2C
jaybehandsome 0:d52e8eda04c3 62 i2c.frequency(400000); // use fast (400 kHz) I2C
jaybehandsome 0:d52e8eda04c3 63
jaybehandsome 0:d52e8eda04c3 64 pc.printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock);
jaybehandsome 0:d52e8eda04c3 65
jaybehandsome 0:d52e8eda04c3 66 t.start();
jaybehandsome 0:d52e8eda04c3 67
jaybehandsome 0:d52e8eda04c3 68
jaybehandsome 0:d52e8eda04c3 69
jaybehandsome 0:d52e8eda04c3 70
jaybehandsome 0:d52e8eda04c3 71 // Read the WHO_AM_I register, this is a good test of communication
jaybehandsome 0:d52e8eda04c3 72 uint8_t whoami = mpu9250.readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250); // Read WHO_AM_I register for MPU-9250
jaybehandsome 0:d52e8eda04c3 73 pc.printf("I AM 0x%x\n\r", whoami); pc.printf("I SHOULD BE 0x71\n\r");
jaybehandsome 0:d52e8eda04c3 74
jaybehandsome 0:d52e8eda04c3 75 if (whoami == 0x71) // WHO_AM_I should always be 0x68
jaybehandsome 0:d52e8eda04c3 76 {
jaybehandsome 0:d52e8eda04c3 77 pc.printf("MPU9250 WHO_AM_I is 0x%x\n\r", whoami);
jaybehandsome 0:d52e8eda04c3 78 pc.printf("MPU9250 is online...\n\r");
jaybehandsome 0:d52e8eda04c3 79
jaybehandsome 0:d52e8eda04c3 80 sprintf(buffer, "0x%x", whoami);
jaybehandsome 0:d52e8eda04c3 81
jaybehandsome 0:d52e8eda04c3 82 wait(1);
jaybehandsome 0:d52e8eda04c3 83
jaybehandsome 0:d52e8eda04c3 84 mpu9250.resetMPU9250(); // Reset registers to default in preparation for device calibration
jaybehandsome 0:d52e8eda04c3 85 mpu9250.MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values
jaybehandsome 0:d52e8eda04c3 86 pc.printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]);
jaybehandsome 0:d52e8eda04c3 87 pc.printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]);
jaybehandsome 0:d52e8eda04c3 88 pc.printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]);
jaybehandsome 0:d52e8eda04c3 89 pc.printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]);
jaybehandsome 0:d52e8eda04c3 90 pc.printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]);
jaybehandsome 0:d52e8eda04c3 91 pc.printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]);
jaybehandsome 0:d52e8eda04c3 92 mpu9250.calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers
jaybehandsome 0:d52e8eda04c3 93 pc.printf("x gyro bias = %f\n\r", gyroBias[0]);
jaybehandsome 0:d52e8eda04c3 94 pc.printf("y gyro bias = %f\n\r", gyroBias[1]);
jaybehandsome 0:d52e8eda04c3 95 pc.printf("z gyro bias = %f\n\r", gyroBias[2]);
jaybehandsome 0:d52e8eda04c3 96 pc.printf("x accel bias = %f\n\r", accelBias[0]);
jaybehandsome 0:d52e8eda04c3 97 pc.printf("y accel bias = %f\n\r", accelBias[1]);
jaybehandsome 0:d52e8eda04c3 98 pc.printf("z accel bias = %f\n\r", accelBias[2]);
jaybehandsome 0:d52e8eda04c3 99 wait(2);
jaybehandsome 0:d52e8eda04c3 100 mpu9250.initMPU9250();
jaybehandsome 0:d52e8eda04c3 101 pc.printf("MPU9250 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
jaybehandsome 0:d52e8eda04c3 102 mpu9250.initAK8963(magCalibration);
jaybehandsome 0:d52e8eda04c3 103 pc.printf("AK8963 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer
jaybehandsome 0:d52e8eda04c3 104 pc.printf("Accelerometer full-scale range = %f g\n\r", 2.0f*(float)(1<<Ascale));
jaybehandsome 0:d52e8eda04c3 105 pc.printf("Gyroscope full-scale range = %f deg/s\n\r", 250.0f*(float)(1<<Gscale));
jaybehandsome 0:d52e8eda04c3 106 if(Mscale == 0) pc.printf("Magnetometer resolution = 14 bits\n\r");
jaybehandsome 0:d52e8eda04c3 107 if(Mscale == 1) pc.printf("Magnetometer resolution = 16 bits\n\r");
jaybehandsome 0:d52e8eda04c3 108 if(Mmode == 2) pc.printf("Magnetometer ODR = 8 Hz\n\r");
jaybehandsome 0:d52e8eda04c3 109 if(Mmode == 6) pc.printf("Magnetometer ODR = 100 Hz\n\r");
jaybehandsome 0:d52e8eda04c3 110 wait(1);
jaybehandsome 0:d52e8eda04c3 111 }
jaybehandsome 0:d52e8eda04c3 112 else
jaybehandsome 0:d52e8eda04c3 113 {
jaybehandsome 0:d52e8eda04c3 114 pc.printf("Could not connect to MPU9250: \n\r");
jaybehandsome 0:d52e8eda04c3 115 pc.printf("%#x \n", whoami);
jaybehandsome 0:d52e8eda04c3 116
jaybehandsome 0:d52e8eda04c3 117
jaybehandsome 0:d52e8eda04c3 118 sprintf(buffer, "WHO_AM_I 0x%x", whoami);
jaybehandsome 0:d52e8eda04c3 119
jaybehandsome 0:d52e8eda04c3 120
jaybehandsome 0:d52e8eda04c3 121 while(1) ; // Loop forever if communication doesn't happen
jaybehandsome 0:d52e8eda04c3 122 }
jaybehandsome 0:d52e8eda04c3 123
jaybehandsome 0:d52e8eda04c3 124 mpu9250.getAres(); // Get accelerometer sensitivity
jaybehandsome 0:d52e8eda04c3 125 mpu9250.getGres(); // Get gyro sensitivity
jaybehandsome 0:d52e8eda04c3 126 mpu9250.getMres(); // Get magnetometer sensitivity
jaybehandsome 0:d52e8eda04c3 127 pc.printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/aRes);
jaybehandsome 0:d52e8eda04c3 128 pc.printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/gRes);
jaybehandsome 0:d52e8eda04c3 129 pc.printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mRes);
jaybehandsome 0:d52e8eda04c3 130 magbias[0] = +470.; // User environmental x-axis correction in milliGauss, should be automatically calculated
jaybehandsome 0:d52e8eda04c3 131 magbias[1] = +120.; // User environmental x-axis correction in milliGauss
jaybehandsome 0:d52e8eda04c3 132 magbias[2] = +125.; // User environmental x-axis correction in milliGauss
jaybehandsome 0:d52e8eda04c3 133
jaybehandsome 0:d52e8eda04c3 134 while(1) {
jaybehandsome 0:d52e8eda04c3 135
jaybehandsome 0:d52e8eda04c3 136 // If intPin goes high, all data registers have new data
jaybehandsome 0:d52e8eda04c3 137 if(mpu9250.readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) { // On interrupt, check if data ready interrupt
jaybehandsome 0:d52e8eda04c3 138
jaybehandsome 0:d52e8eda04c3 139 mpu9250.readAccelData(accelCount); // Read the x/y/z adc values
jaybehandsome 0:d52e8eda04c3 140 // Now we'll calculate the accleration value into actual g's
jaybehandsome 0:d52e8eda04c3 141 ax = (float)accelCount[0]*aRes - accelBias[0]; // get actual g value, this depends on scale being set
jaybehandsome 0:d52e8eda04c3 142 ay = (float)accelCount[1]*aRes - accelBias[1];
jaybehandsome 0:d52e8eda04c3 143 az = (float)accelCount[2]*aRes - accelBias[2];
jaybehandsome 0:d52e8eda04c3 144
jaybehandsome 0:d52e8eda04c3 145 mpu9250.readGyroData(gyroCount); // Read the x/y/z adc values
jaybehandsome 0:d52e8eda04c3 146 // Calculate the gyro value into actual degrees per second
jaybehandsome 0:d52e8eda04c3 147 gx = (float)gyroCount[0]*gRes - gyroBias[0]; // get actual gyro value, this depends on scale being set
jaybehandsome 0:d52e8eda04c3 148 gy = (float)gyroCount[1]*gRes - gyroBias[1];
jaybehandsome 0:d52e8eda04c3 149 gz = (float)gyroCount[2]*gRes - gyroBias[2];
jaybehandsome 0:d52e8eda04c3 150
jaybehandsome 0:d52e8eda04c3 151 mpu9250.readMagData(magCount); // Read the x/y/z adc values
jaybehandsome 0:d52e8eda04c3 152 // Calculate the magnetometer values in milliGauss
jaybehandsome 0:d52e8eda04c3 153 // Include factory calibration per data sheet and user environmental corrections
jaybehandsome 0:d52e8eda04c3 154 mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0]; // get actual magnetometer value, this depends on scale being set
jaybehandsome 0:d52e8eda04c3 155 my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];
jaybehandsome 0:d52e8eda04c3 156 mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2];
jaybehandsome 0:d52e8eda04c3 157 }
jaybehandsome 0:d52e8eda04c3 158
jaybehandsome 0:d52e8eda04c3 159 Now = t.read_us();
jaybehandsome 0:d52e8eda04c3 160 deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
jaybehandsome 0:d52e8eda04c3 161 lastUpdate = Now;
jaybehandsome 0:d52e8eda04c3 162
jaybehandsome 0:d52e8eda04c3 163 sum += deltat;
jaybehandsome 0:d52e8eda04c3 164 sumCount++;
jaybehandsome 0:d52e8eda04c3 165
jaybehandsome 0:d52e8eda04c3 166 // if(lastUpdate - firstUpdate > 10000000.0f) {
jaybehandsome 0:d52e8eda04c3 167 // beta = 0.04; // decrease filter gain after stabilized
jaybehandsome 0:d52e8eda04c3 168 // zeta = 0.015; // increasey bias drift gain after stabilized
jaybehandsome 0:d52e8eda04c3 169 // }
jaybehandsome 0:d52e8eda04c3 170
jaybehandsome 0:d52e8eda04c3 171 // Pass gyro rate as rad/s
jaybehandsome 0:d52e8eda04c3 172 // mpu9250.MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
jaybehandsome 0:d52e8eda04c3 173 mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
jaybehandsome 0:d52e8eda04c3 174
jaybehandsome 0:d52e8eda04c3 175 // Serial print and/or display at 0.5 s rate independent of data rates
jaybehandsome 0:d52e8eda04c3 176 delt_t = t.read_ms() - count;
jaybehandsome 0:d52e8eda04c3 177 if (delt_t > 500) { // update LCD once per half-second independent of read rate
jaybehandsome 0:d52e8eda04c3 178
jaybehandsome 0:d52e8eda04c3 179 // pc.printf("ax = %f", 1000*ax);
jaybehandsome 0:d52e8eda04c3 180 // pc.printf(" ay = %f", 1000*ay);
jaybehandsome 0:d52e8eda04c3 181 // pc.printf(" az = %f mg\n\r", 1000*az);
jaybehandsome 0:d52e8eda04c3 182
jaybehandsome 0:d52e8eda04c3 183 pc.printf("gx = %f", gx);
jaybehandsome 0:d52e8eda04c3 184 pc.printf(" gy = %f", gy);
jaybehandsome 0:d52e8eda04c3 185 pc.printf(" gz = %f deg/s\n\r", gz);
jaybehandsome 0:d52e8eda04c3 186
jaybehandsome 0:d52e8eda04c3 187 // pc.printf("gx = %f", mx);
jaybehandsome 0:d52e8eda04c3 188 // pc.printf(" gy = %f", my);
jaybehandsome 0:d52e8eda04c3 189 // pc.printf(" gz = %f mG\n\r", mz);
jaybehandsome 0:d52e8eda04c3 190
jaybehandsome 0:d52e8eda04c3 191 tempCount = mpu9250.readTempData(); // Read the adc values
jaybehandsome 0:d52e8eda04c3 192 temperature = ((float) tempCount) / 333.87f + 21.0f; // Temperature in degrees Centigrade
jaybehandsome 0:d52e8eda04c3 193 //pc.printf(" temperature = %f C\n\r", temperature);
jaybehandsome 0:d52e8eda04c3 194 //
jaybehandsome 0:d52e8eda04c3 195 // pc.printf("q0 = %f\n\r", q[0]);
jaybehandsome 0:d52e8eda04c3 196 // pc.printf("q1 = %f\n\r", q[1]);
jaybehandsome 0:d52e8eda04c3 197 // pc.printf("q2 = %f\n\r", q[2]);
jaybehandsome 0:d52e8eda04c3 198 // pc.printf("q3 = %f\n\r", q[3]);
jaybehandsome 0:d52e8eda04c3 199
jaybehandsome 0:d52e8eda04c3 200 /* lcd.clear();
jaybehandsome 0:d52e8eda04c3 201 lcd.printString("MPU9250", 0, 0);
jaybehandsome 0:d52e8eda04c3 202 lcd.printString("x y z", 0, 1);
jaybehandsome 0:d52e8eda04c3 203 sprintf(buffer, "%d %d %d mg", (int)(1000.0f*ax), (int)(1000.0f*ay), (int)(1000.0f*az));
jaybehandsome 0:d52e8eda04c3 204 lcd.printString(buffer, 0, 2);
jaybehandsome 0:d52e8eda04c3 205 sprintf(buffer, "%d %d %d deg/s", (int)gx, (int)gy, (int)gz);
jaybehandsome 0:d52e8eda04c3 206 lcd.printString(buffer, 0, 3);
jaybehandsome 0:d52e8eda04c3 207 sprintf(buffer, "%d %d %d mG", (int)mx, (int)my, (int)mz);
jaybehandsome 0:d52e8eda04c3 208 lcd.printString(buffer, 0, 4);
jaybehandsome 0:d52e8eda04c3 209 */
jaybehandsome 0:d52e8eda04c3 210 // Define output variables from updated quaternion---these are Tait-Bryan angles, commonly used in aircraft orientation.
jaybehandsome 0:d52e8eda04c3 211 // In this coordinate system, the positive z-axis is down toward Earth.
jaybehandsome 0:d52e8eda04c3 212 // 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.
jaybehandsome 0:d52e8eda04c3 213 // Pitch is angle between sensor x-axis and Earth ground plane, toward the Earth is positive, up toward the sky is negative.
jaybehandsome 0:d52e8eda04c3 214 // Roll is angle between sensor y-axis and Earth ground plane, y-axis up is positive roll.
jaybehandsome 0:d52e8eda04c3 215 // These arise from the definition of the homogeneous rotation matrix constructed from quaternions.
jaybehandsome 0:d52e8eda04c3 216 // Tait-Bryan angles as well as Euler angles are non-commutative; that is, the get the correct orientation the rotations must be
jaybehandsome 0:d52e8eda04c3 217 // applied in the correct order which for this configuration is yaw, pitch, and then roll.
jaybehandsome 0:d52e8eda04c3 218 // For more see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles which has additional links.
jaybehandsome 0:d52e8eda04c3 219 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]);
jaybehandsome 0:d52e8eda04c3 220 pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2]));
jaybehandsome 0:d52e8eda04c3 221 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]);
jaybehandsome 0:d52e8eda04c3 222 pitch *= 180.0f / PI;
jaybehandsome 0:d52e8eda04c3 223 yaw *= 180.0f / PI;
jaybehandsome 0:d52e8eda04c3 224 yaw -= 13.8f; // Declination at Danville, California is 13 degrees 48 minutes and 47 seconds on 2014-04-04
jaybehandsome 0:d52e8eda04c3 225 roll *= 180.0f / PI;
jaybehandsome 0:d52e8eda04c3 226
jaybehandsome 0:d52e8eda04c3 227 // pc.printf("Yaw, Pitch, Roll: %f %f %f\n\r", yaw, pitch, roll);
jaybehandsome 0:d52e8eda04c3 228 // pc.printf("average rate = %f\n\r", (float) sumCount/sum);
jaybehandsome 0:d52e8eda04c3 229 // sprintf(buffer, "YPR: %f %f %f", yaw, pitch, roll);
jaybehandsome 0:d52e8eda04c3 230 // lcd.printString(buffer, 0, 4);
jaybehandsome 0:d52e8eda04c3 231 // sprintf(buffer, "rate = %f", (float) sumCount/sum);
jaybehandsome 0:d52e8eda04c3 232 // lcd.printString(buffer, 0, 5);
jaybehandsome 0:d52e8eda04c3 233
jaybehandsome 0:d52e8eda04c3 234 myled= !myled;
jaybehandsome 0:d52e8eda04c3 235 count = t.read_ms();
jaybehandsome 0:d52e8eda04c3 236
jaybehandsome 0:d52e8eda04c3 237 if(count > 1<<21) {
jaybehandsome 0:d52e8eda04c3 238 t.start(); // start the timer over again if ~30 minutes has passed
jaybehandsome 0:d52e8eda04c3 239 count = 0;
jaybehandsome 0:d52e8eda04c3 240 deltat= 0;
jaybehandsome 0:d52e8eda04c3 241 lastUpdate = t.read_us();
jaybehandsome 0:d52e8eda04c3 242 }
jaybehandsome 0:d52e8eda04c3 243 sum = 0;
jaybehandsome 0:d52e8eda04c3 244 sumCount = 0;
jaybehandsome 0:d52e8eda04c3 245 }
jaybehandsome 0:d52e8eda04c3 246 }
jaybehandsome 0:d52e8eda04c3 247
jaybehandsome 0:d52e8eda04c3 248 }