main.cpp

00001 /* ICM20948 Basic Example Code
00002  by: Kris Winer
00003  modified by Eric Nativel MBEB_OS6 port 
00004  date: 29, MArch 2021
00005  license: Beerware - Use this code however you'd like. If you
00006  find it useful you can buy me a beer some time.
00007  Modified by Brent Wilkins July 19, 2016
00008  Demonstrate basic ICM20948 functionality including parameterizing the register
00009  addresses, initializing the sensor, getting properly scaled accelerometer,
00010  gyroscope, and magnetometer data out. Added display functions to allow display
00011  to on breadboard monitor. Addition of 9 DoF sensor fusion using open source
00012  Madgwick and Mahony filter algorithms. Pimoroni icm20948 and stm32L432kc nucleo board
00013  */
00014 
00015 #include "mbed.h"
00016 #include "ahrs.h"
00017 #include "icm20948.h"
00018 #include <cstdio>
00019 #include <stdint.h>
00020 
00021 using namespace std::chrono;
00022 Timer t1;
00023 typedef unsigned char byte;
00024 float selft[6];
00025 static BufferedSerial pc(USBTX, USBRX);
00026 
00027 
00028 char msg[255];
00029 
00030 void setup()
00031 {
00032      //Set up I2C
00033     
00034     pc.set_baud(9600);
00035     pc.set_format(
00036         /* bits */ 8,
00037         /* parity */ BufferedSerial::None,
00038         /* stop bit */ 1
00039     );
00040   // Reset ICM20948
00041   begin();
00042  
00043   writeByte(ICM20948_ADDRESS, PWR_MGMT_1, READ_FLAGS);
00044   thread_sleep_for(100);
00045   writeByte(ICM20948_ADDRESS, PWR_MGMT_1, 0x01);
00046   thread_sleep_for(100);
00047   
00048   // Read the WHO_AM_I register, this is a good test of communication
00049   byte c = readByte(ICM20948_ADDRESS, WHO_AM_I_ICM20948);
00050   sprintf(msg,"ICM20948 I AM 0x %x I should be 0x %x",c,0xEA);
00051   pc.write(msg, strlen(msg));
00052   if (c == 0xEA) // WHO_AM_I should always be 0x71
00053   {
00054     sprintf(msg,"ICM20948 is online...\n");
00055     pc.write(msg, strlen(msg));
00056    // writeByte(ICM20948_ADDRESS, REG_BANK_SEL, 0x10);
00057     // Start by performing self test and reporting values
00058     ICM20948SelfTest(selft);
00059     sprintf(msg,"x-axis self test: acceleration trim within : %f of factory value\n",selft[0]);
00060     pc.write(msg, strlen(msg));
00061     sprintf(msg,"y-axis self test: acceleration trim within : %f of factory value\n",selft[1]);
00062     pc.write(msg, strlen(msg));
00063     sprintf(msg,"z-axis self test: acceleration trim within : %f  of factory value\n",selft[2]);
00064     pc.write(msg, strlen(msg));
00065     sprintf(msg,"x-axis self test: gyration trim within : %f of factory value\n",selft[3]);
00066     pc.write(msg, strlen(msg));
00067     sprintf(msg,"y-axis self test: gyration trim within : %f of factory value\n",selft[4]);
00068     pc.write(msg, strlen(msg));
00069     sprintf(msg,"z-axis self test: gyration trim within : %f of factory value\n",selft[5]);
00070     pc.write(msg, strlen(msg));
00071         // Calibrate gyro and accelerometers, load biases in bias registers
00072     calibrateICM20948(gyroBias, accelBias);
00073 
00074     initICM20948();
00075     // Initialize device for active mode read of acclerometer, gyroscope, and
00076     // temperature
00077     sprintf(msg,"ICM20948 initialized for active data mode....\n");
00078     pc.write(msg, strlen(msg));
00079         // Read the WHO_AM_I register of the magnetometer, this is a good test of
00080     // communication
00081     tempCount =readTempData();  // Read the adc values
00082         // Temperature in degrees Centigrade
00083     temperature = ((float) tempCount) / 333.87 + 21.0;
00084         // Print temperature in degrees Centigrade
00085     sprintf(msg,"Temperature is %f degrees C\n",temperature);
00086     pc.write(msg, strlen(msg));
00087     byte d = readByte(AK09916_ADDRESS<<1, WHO_AM_I_AK09916);
00088     sprintf(msg,"AK8963 I AM 0x %x  I should be 0x %d\n",d,0x09);
00089     pc.write(msg, strlen(msg));
00090 
00091     if (d != 0x09)
00092     {
00093       // Communication failed, stop here
00094     sprintf(msg,"Communication with magnetometer failed, abort!\n");
00095     pc.write(msg, strlen(msg));
00096     exit(0);
00097     }
00098 
00099     // Get magnetometer calibration from AK8963 ROM
00100     initAK09916();
00101     // Initialize device for active mode read of magnetometer
00102     sprintf(msg,"AK09916 initialized for active data mode....\n");
00103     pc.write(msg, strlen(msg));
00104    
00105   
00106 
00107     // Get sensor resolutions, only need to do this once
00108     getAres();
00109     getGres();
00110     getMres();
00111     // The next call delays for 4 seconds, and then records about 15 seconds of
00112     // data to calculate bias and scale.
00113     magCalICM20948(magBias, magScale);
00114     sprintf(msg,"AK09916 mag biases (mG)\n %f\n%f\n%f\n",magBias[0],magBias[1],magBias[2]);
00115     pc.write(msg, strlen(msg));
00116    sprintf(msg,"AK09916 mag scale (mG)\n %f\n%f\n%f\n",magScale[0],magScale[1],magScale[2]);
00117     pc.write(msg, strlen(msg));
00118     thread_sleep_for(2000); // Add delay to see results before pc spew of data
00119   } // if (c == 0x71)
00120   else
00121   {
00122     sprintf(msg,"Could not connect to ICM20948: 0x%x",c);
00123     pc.write(msg, strlen(msg));
00124     // Communication failed, stop here
00125     sprintf(msg," Communication failed, abort!\n");
00126     pc.write(msg, strlen(msg));
00127     exit(0);
00128   }
00129 }
00130 int main(void)
00131 {int i=0;
00132     setup();
00133 while(i<100)
00134 {
00135   // If intPin goes high, all data registers have new data
00136   // On interrupt, check if data ready interrupt
00137   if (readByte(ICM20948_ADDRESS, INT_STATUS_1) & 0x01)
00138 {
00139     readAccelData(accelCount);  // Read the x/y/z adc values
00140 
00141     // Now we'll calculate the accleration value into actual g's
00142     // This depends on scale being set
00143     ax = (float)accelCount[0] * aRes; // - accelBias[0];
00144     ay = (float)accelCount[1] * aRes; // - accelBias[1];
00145     az = (float)accelCount[2] * aRes; // - accelBias[2];
00146     sprintf(msg,"X-acceleration: %f mg\n",1000*ax);
00147     pc.write(msg, strlen(msg));
00148     sprintf(msg,"Y-acceleration: %f mg\n",1000*ay);
00149     pc.write(msg, strlen(msg));
00150     sprintf(msg,"Z-acceleration: %f mg\n",1000*az);
00151     pc.write(msg, strlen(msg));
00152     readGyroData(gyroCount);  // Read the x/y/z adc values
00153 
00154     // Calculate the gyro value into actual degrees per second
00155     // This depends on scale being set
00156     gx = (float)gyroCount[0] * gRes;
00157     gy = (float)gyroCount[1] * gRes;
00158     gz = (float)gyroCount[2] * gRes;
00159 sprintf(msg,"x -gyroscope: %f and bias %f deg/s\n",gx,gyroBias[0]);
00160         pc.write(msg, strlen(msg));
00161    readMagData(magCount);  // Read the x/y/z adc values
00162 
00163     // Calculate the magnetometer values in milliGauss
00164     // Include factory calibration per data sheet and user environmental
00165     // corrections
00166     // Get actual magnetometer value, this depends on scale being set
00167     mx = (float)magCount[0] * mRes - magBias[0];
00168     my = (float)magCount[1] * mRes - magBias[1];
00169     mz = (float)magCount[2] * mRes - magBias[2];
00170    // if (readByte(ICM20948_ADDRESS, INT_STATUS) & 0x01)
00171 
00172   // Must be called before updating quaternions!
00173   updateTime();
00174 
00175   // Sensors x (y)-axis of the accelerometer is aligned with the y (x)-axis of
00176   // the magnetometer; the magnetometer z-axis (+ down) is opposite to z-axis
00177   // (+ up) of accelerometer and gyro! We have to make some allowance for this
00178   // orientationmismatch in feeding the output to the quaternion filter. For the
00179   // ICM20948, we have chosen a magnetic rotation that keeps the sensor forward
00180   // along the x-axis just like in the LSM9DS0 sensor. This rotation can be
00181   // modified to allow any convenient orientation convention. This is ok by
00182   // aircraft orientation standards! Pass gyro rate as rad/s
00183   MahonyQuaternionUpdate(ax, ay, az, gx * DEG_TO_RAD,
00184                          gy * DEG_TO_RAD, gz * DEG_TO_RAD, my,
00185                          mx, mz, deltat);
00186 
00187 // Define output variables from updated quaternion---these are Tait-Bryan
00188 // angles, commonly used in aircraft orientation. In this coordinate system,
00189 // the positive z-axis is down toward Earth. Yaw is the angle between Sensor
00190 // x-axis and Earth magnetic North (or true North if corrected for local
00191 // declination, looking down on the sensor positive yaw is counterclockwise.
00192 // Pitch is angle between sensor x-axis and Earth ground plane, toward the
00193 // Earth is positive, up toward the sky is negative. Roll is angle between
00194 // sensor y-axis and Earth ground plane, y-axis up is positive roll. These
00195 // arise from the definition of the homogeneous rotation matrix constructed
00196 // from quaternions. Tait-Bryan angles as well as Euler angles are
00197 // non-commutative; that is, the get the correct orientation the rotations
00198 // must be applied in the correct order which for this configuration is yaw,
00199 // pitch, and then roll.
00200 // For more see
00201 // http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles
00202 // which has additional links.
00203       yaw   = atan2(2.0f * (*(getQ()+1) * *(getQ()+2) + *getQ()
00204                     * *(getQ()+3)), *getQ() * *getQ() + *(getQ()+1)
00205                     * *(getQ()+1) - *(getQ()+2) * *(getQ()+2) - *(getQ()+3)
00206                     * *(getQ()+3));
00207       pitch = -asin(2.0f * (*(getQ()+1) * *(getQ()+3) - *getQ()
00208                     * *(getQ()+2)));
00209       roll  = atan2(2.0f * (*getQ() * *(getQ()+1) + *(getQ()+2)
00210                     * *(getQ()+3)), *getQ() * *getQ() - *(getQ()+1)
00211                     * *(getQ()+1) - *(getQ()+2) * *(getQ()+2) + *(getQ()+3)
00212                     * *(getQ()+3));
00213       pitch *= RAD_TO_DEG;
00214       yaw   *= RAD_TO_DEG;
00215 
00216       // Declination of SparkFun Electronics (40°05'26.6"N 105°11'05.9"W) is
00217       //    8° 30' E  ± 0° 21' (or 8.5°) on 2016-07-19
00218       //    1° 46' E 2021-03-27
00219       // - http://www.ngdc.noaa.gov/geomag-web/#declination
00220       yaw  -= 1.7666;
00221       roll *= RAD_TO_DEG;
00222 
00223      
00224         sprintf(msg,"Yaw %f, Pitch %f, Roll %f\n ",yaw,pitch,roll);
00225         pc.write(msg, strlen(msg));
00226     sumCount = 0;
00227     sum = 0;
00228 }    
00229       i++;
00230      //thread_sleep_for(200);
00231     }
00232   return 0;
00233 }