Team Alpha / Mbed 2 deprecated Accelerometer_gyro

testing gyro get orientation,acceleration states get difference in two states of the device

Dependencies:   mbed

Fork of testing_gyro by Dimitar Borisov

main.cpp@0:91b1274ec397, 2014-03-18 (annotated)

Committer:
liamg
Date:
Tue Mar 18 05:22:01 2014 +0000
Revision:
0:91b1274ec397
Child:
1:3b2260aff305
Completed without multibyte read function

Who changed what in which revision?

UserRevisionLine numberNew contents of line
liamg 0:91b1274ec397 1 // MBED reference code for the ST Micro STEVAL-MKI124V1 header board
liamg 0:91b1274ec397 2 // This board has: LPS331 pressure/temperature sensor, L3GD20 gyroscope and LSM303DLHC magnetometer/accelerometer
liamg 0:91b1274ec397 3 // Code accesses each of the 3 MEMS sensors and calculates pressure, temp, heading, tilt, roll and angular velocity
liamg 0:91b1274ec397 4 // Code is not optimized for efficienecy but instead for clarity of how you use the sensors
liamg 0:91b1274ec397 5 // ST application note AN3192 was key in developing the tilt-corrected compass
liamg 0:91b1274ec397 6 // Developed on an LPC1768
liamg 0:91b1274ec397 7 // By Liam Goudge. March 2014
liamg 0:91b1274ec397 8
liamg 0:91b1274ec397 9 #include "mbed.h"
liamg 0:91b1274ec397 10 #include "MKI124V1.h"
liamg 0:91b1274ec397 11 #include "math.h"
liamg 0:91b1274ec397 12
liamg 0:91b1274ec397 13 DigitalOut myled(LED1);
liamg 0:91b1274ec397 14 Serial pc(USBTX, USBRX); // tx, rx for USB debug printf to terminal console
liamg 0:91b1274ec397 15 I2C i2c(p28, p27); // LPC1768 I2C pin allocation
liamg 0:91b1274ec397 16
liamg 0:91b1274ec397 17 // Globals
liamg 0:91b1274ec397 18 int16_t const Offset_mX=-40.0;
liamg 0:91b1274ec397 19 int16_t const Offset_mY=-115.0;
liamg 0:91b1274ec397 20 float const RadtoDeg=(180.0/3.141592654);
liamg 0:91b1274ec397 21
liamg 0:91b1274ec397 22
liamg 0:91b1274ec397 23 char readByte(char address, char reg)
liamg 0:91b1274ec397 24 // Reads one byte from an I2C address
liamg 0:91b1274ec397 25 // Didn't bother to make a multi-byte version to read in X,Y,Z low/high series of registers because...
liamg 0:91b1274ec397 26 // the data registers of all sensors they are in the same XL,XH,YL,YH,ZL,ZH order apart from the magnetometer which is XH,XL,ZH,ZL,YH,YL...
liamg 0:91b1274ec397 27 {
liamg 0:91b1274ec397 28 char result;
liamg 0:91b1274ec397 29
liamg 0:91b1274ec397 30 i2c.start();
liamg 0:91b1274ec397 31 i2c.write(address); // Slave address with direction=write
liamg 0:91b1274ec397 32 i2c.write(reg); // Subaddress (register)
liamg 0:91b1274ec397 33
liamg 0:91b1274ec397 34 i2c.start(); // Break transmission to change bus direction
liamg 0:91b1274ec397 35 i2c.write(address + 1); // Slave address with direction=read [bit0=1]
liamg 0:91b1274ec397 36
liamg 0:91b1274ec397 37 result = i2c.read(0);
liamg 0:91b1274ec397 38 i2c.stop();
liamg 0:91b1274ec397 39 return (result);
liamg 0:91b1274ec397 40 }
liamg 0:91b1274ec397 41
liamg 0:91b1274ec397 42 void writeByte(char address, char reg,char value)
liamg 0:91b1274ec397 43 // Sends 1 byte to an I2C address
liamg 0:91b1274ec397 44 {
liamg 0:91b1274ec397 45 i2c.start();
liamg 0:91b1274ec397 46 i2c.write(address); // Slave address
liamg 0:91b1274ec397 47 i2c.write(reg); // Subaddress (register)
liamg 0:91b1274ec397 48 i2c.write(value);
liamg 0:91b1274ec397 49 i2c.stop();
liamg 0:91b1274ec397 50
liamg 0:91b1274ec397 51 }
liamg 0:91b1274ec397 52
liamg 0:91b1274ec397 53 void initSensors (void)
liamg 0:91b1274ec397 54 // Switch on and set up the 3 on-board sensors
liamg 0:91b1274ec397 55 {
liamg 0:91b1274ec397 56 pc.printf("--------------------------------------\n");
liamg 0:91b1274ec397 57 pc.printf("\nSTM MEMS eval board sensor init \n");
liamg 0:91b1274ec397 58
liamg 0:91b1274ec397 59 // LSM303DLHC Magnetic sensor
liamg 0:91b1274ec397 60 pc.printf("LSM303DLHC ping (should reply 0x48): %x \n",readByte(LSM303_m,mIRA_REG_M));
liamg 0:91b1274ec397 61 writeByte(LSM303_m,mCRA_REG_M,0x94); //switch on temperature sensor and set Output Data Rate to 30Hz
liamg 0:91b1274ec397 62 writeByte(LSM303_m,mCRB_REG_M,0x20); // Set the gain for +/- 1.3 Gauss full scale range
liamg 0:91b1274ec397 63 writeByte(LSM303_m,mMR_REG_M,0x0); // Continuous convertion mode
liamg 0:91b1274ec397 64
liamg 0:91b1274ec397 65 // LSM303DLHC Accelerometer
liamg 0:91b1274ec397 66 writeByte(LSM303_a,aCTRL_REG1_A ,0x37); // Set 25Hz ODR, everything else on
liamg 0:91b1274ec397 67 writeByte(LSM303_a,aCTRL_REG4_A ,0x08); // Set full scale to +/- 2g sensitivity and high rez mode
liamg 0:91b1274ec397 68
liamg 0:91b1274ec397 69 // LPS331 Pressure sensor
liamg 0:91b1274ec397 70 pc.printf("LPS331 ping (should reply 0xBB): %x \n",readByte(LPS331addr,pWHO_AM_I));
liamg 0:91b1274ec397 71 writeByte(LPS331addr,pCTRL_REG1,0x90); // Switch on pressure sensor and select 1Hz ODR. If you select one-shot then sensor powers itself down after every reading...
liamg 0:91b1274ec397 72 writeByte(LPS331addr,pRES_CONF,0x70); // Temp and pressure noise reduction. Sets # of internal measurements that are averaged to 1 reading. Default is 0x7A (temp rez=128, press=512)
liamg 0:91b1274ec397 73
liamg 0:91b1274ec397 74 // L3GD20 gyro
liamg 0:91b1274ec397 75 printf("Ping L3GD20 (should reply 0xD4): %x \n",readByte(L3GD20_ADDR,gWHO_AM_I));
liamg 0:91b1274ec397 76 writeByte(L3GD20_ADDR,gCTRL_REG1,0x0F); // Set ODR to 95Hz, BW to 12.5Hz, enable axes and turn on device
liamg 0:91b1274ec397 77 writeByte(L3GD20_ADDR,gCTRL_REG4,0x10); // Full scale selected at 500dps (degrees per second)
liamg 0:91b1274ec397 78 printf("L3GD20 gyro Temp: %x degrees C \n",readByte(L3GD20_ADDR,gOUT_TEMP));
liamg 0:91b1274ec397 79
liamg 0:91b1274ec397 80 pc.printf("--------------------------------------\n \n");
liamg 0:91b1274ec397 81 wait(1); // Wait for settings to stabilize
liamg 0:91b1274ec397 82 }
liamg 0:91b1274ec397 83
liamg 0:91b1274ec397 84 void LPS331(SensorState_t state)
liamg 0:91b1274ec397 85 // Read the pressure sensor
liamg 0:91b1274ec397 86 {
liamg 0:91b1274ec397 87 uint8_t tempL,tempH,pressXL,pressL,pressH;
liamg 0:91b1274ec397 88 int16_t temp;
liamg 0:91b1274ec397 89 int32_t press24;
liamg 0:91b1274ec397 90 float pressure;
liamg 0:91b1274ec397 91
liamg 0:91b1274ec397 92 // Measure temperature
liamg 0:91b1274ec397 93 tempL=readByte(LPS331addr,pTEMP_OUT_L);
liamg 0:91b1274ec397 94 tempH=readByte(LPS331addr,pTEMP_OUT_H);
liamg 0:91b1274ec397 95 temp=(tempH << 8) | tempL; // 16-bit 2's complement data
liamg 0:91b1274ec397 96
liamg 0:91b1274ec397 97 state.tempC=((float) temp / 480.0) + 42.5; // per equation on page 29 of the spec
liamg 0:91b1274ec397 98
liamg 0:91b1274ec397 99 pc.printf("Pressure sensor temperature %.1f degreesC \n",state.tempC);
liamg 0:91b1274ec397 100
liamg 0:91b1274ec397 101 // Pressure test
liamg 0:91b1274ec397 102 pressXL=readByte(LPS331addr,pPRESS_OUT_XL);
liamg 0:91b1274ec397 103 pressL=readByte(LPS331addr,pPRESS_OUT_L);
liamg 0:91b1274ec397 104 pressH=readByte(LPS331addr,pPRESS_OUT_H);
liamg 0:91b1274ec397 105
liamg 0:91b1274ec397 106 press24=(pressH << 16) | (pressL << 8) | pressXL ; // 24-bit 2's complement data
liamg 0:91b1274ec397 107 pressure = (float)press24/4096.0; // Sensitivity is 4096 LSB per milibar
liamg 0:91b1274ec397 108
liamg 0:91b1274ec397 109 pc.printf("Pressure %.1f mbars or %.1f inches Hg\n", pressure, (pressure*0.0295)+0.029);
liamg 0:91b1274ec397 110
liamg 0:91b1274ec397 111 }
liamg 0:91b1274ec397 112
liamg 0:91b1274ec397 113 void LSM303 (SensorState_t * state)
liamg 0:91b1274ec397 114 // Magnetometer and accelerometer
liamg 0:91b1274ec397 115 {
liamg 0:91b1274ec397 116 char xL, xH, yL, yH, zL, zH;
liamg 0:91b1274ec397 117 int16_t mX, mY, mZ,aX,aY,aZ;
liamg 0:91b1274ec397 118 float pitch,roll,faX,faY;
liamg 0:91b1274ec397 119
liamg 0:91b1274ec397 120 xL=readByte(LSM303_m,mOUT_X_L_M);
liamg 0:91b1274ec397 121 xH=readByte(LSM303_m,mOUT_X_H_M);
liamg 0:91b1274ec397 122 yL=readByte(LSM303_m,mOUT_Y_L_M);
liamg 0:91b1274ec397 123 yH=readByte(LSM303_m,mOUT_Y_H_M);
liamg 0:91b1274ec397 124 zL=readByte(LSM303_m,mOUT_Z_L_M);
liamg 0:91b1274ec397 125 zH=readByte(LSM303_m,mOUT_Z_H_M);
liamg 0:91b1274ec397 126
liamg 0:91b1274ec397 127 mX=(xH<<8) | (xL); // 16-bit 2's complement data
liamg 0:91b1274ec397 128 mY=(yH<<8) | (yL);
liamg 0:91b1274ec397 129 mZ=(zH<<8) | (zL);
liamg 0:91b1274ec397 130
liamg 0:91b1274ec397 131 //pc.printf("mX=%hd %X mY=%hd %X mZ=%hd %X \n",mX,mX,mY,mY,mZ,mZ);
liamg 0:91b1274ec397 132
liamg 0:91b1274ec397 133 mX=mX-Offset_mX; // These are callibration co-efficients to deal with non-zero soft iron magnetic offset
liamg 0:91b1274ec397 134 mY=mY-Offset_mY;
liamg 0:91b1274ec397 135
liamg 0:91b1274ec397 136 xL=readByte(LSM303_a,aOUT_X_L_A);
liamg 0:91b1274ec397 137 xH=readByte(LSM303_a,aOUT_X_H_A);
liamg 0:91b1274ec397 138 yL=readByte(LSM303_a,aOUT_Y_L_A);
liamg 0:91b1274ec397 139 yH=readByte(LSM303_a,aOUT_Y_H_A);
liamg 0:91b1274ec397 140 zL=readByte(LSM303_a,aOUT_Z_L_A);
liamg 0:91b1274ec397 141 zH=readByte(LSM303_a,aOUT_Z_H_A);
liamg 0:91b1274ec397 142
liamg 0:91b1274ec397 143 aX=(signed short) ( (xH<<8) | (xL) ) >> 4; // 12-bit data from ADC. Cast ensures that the 2's complement sign is not lost in the right shift.
liamg 0:91b1274ec397 144 aY=(signed short) ( (yH<<8) | (yL) ) >> 4;
liamg 0:91b1274ec397 145 aZ=(signed short) ( (zH<<8) | (zL) ) >> 4;
liamg 0:91b1274ec397 146
liamg 0:91b1274ec397 147 //pc.printf("aX=%hd %X aY=%hd %X aZ=%hd %X \n",aX,aX,aY,aY,aZ,aZ);
liamg 0:91b1274ec397 148
liamg 0:91b1274ec397 149 faX=((float) aX) /2000.0; // Accelerometer scale I chose is 1mg per LSB with range +/-2g. So to normalize for full scale need to divide by 2000.
liamg 0:91b1274ec397 150 faY=((float) aY) /2000.0; // If you don't do this the pitch and roll calcs will not work (inverse cosine of a value greater than 1)
liamg 0:91b1274ec397 151 //faZ=((float) aZ) /2000.0; // Not used in a calc so comment out to avoid the compiler warning
liamg 0:91b1274ec397 152
liamg 0:91b1274ec397 153 // Trigonometry derived from STM app note AN3192 and from WikiRobots
liamg 0:91b1274ec397 154 pitch = asin((float) -faX*2); // Dividing faX and faY by 1000 rather than 2000 seems to give better tilt immunity. Do it here rather than above to preserve true mg units of faX etc
liamg 0:91b1274ec397 155 roll = asin(faY*2/cos(pitch));
liamg 0:91b1274ec397 156
liamg 0:91b1274ec397 157 float xh = mX * cos(pitch) + mZ * sin(pitch);
liamg 0:91b1274ec397 158 float yh = mX * sin(roll) * sin(pitch) + mY * cos(roll) - mZ * sin(roll) * cos(pitch);
liamg 0:91b1274ec397 159 float zh = -mX * cos(roll) * sin(pitch) + mY * sin(roll) + mZ * cos(roll) * cos(pitch);
liamg 0:91b1274ec397 160
liamg 0:91b1274ec397 161 float heading = atan2(yh, xh) * RadtoDeg; // Note use of atan2 rather than atan since better for working with quadrants
liamg 0:91b1274ec397 162 if (yh < 0)
liamg 0:91b1274ec397 163 heading=360+heading;
liamg 0:91b1274ec397 164
liamg 0:91b1274ec397 165 state->heading=heading;
liamg 0:91b1274ec397 166 state->pitch=pitch;
liamg 0:91b1274ec397 167 state->roll=roll;
liamg 0:91b1274ec397 168
liamg 0:91b1274ec397 169 pc.printf("Orientation (deg): Pitch: %5.1f Roll: %5.1f Heading: %5.1f \n",pitch*RadtoDeg,roll*RadtoDeg,heading);
liamg 0:91b1274ec397 170 pc.printf("Acceleration (mg): Forward: %5hd Left: %5hd Up: %5hd \n",aX,aY,aZ);
liamg 0:91b1274ec397 171
liamg 0:91b1274ec397 172 }
liamg 0:91b1274ec397 173
liamg 0:91b1274ec397 174 void L3GD20(void) // Gyro
liamg 0:91b1274ec397 175 {
liamg 0:91b1274ec397 176 char xL, xH, yL, yH, zL, zH;
liamg 0:91b1274ec397 177 int16_t gX, gY, gZ;
liamg 0:91b1274ec397 178 float rorX,rorY,rorZ;
liamg 0:91b1274ec397 179
liamg 0:91b1274ec397 180 xL=readByte(L3GD20_ADDR,gOUT_X_L);
liamg 0:91b1274ec397 181 xH=readByte(L3GD20_ADDR,gOUT_X_H);
liamg 0:91b1274ec397 182 yL=readByte(L3GD20_ADDR,gOUT_Y_L);
liamg 0:91b1274ec397 183 yH=readByte(L3GD20_ADDR,gOUT_Y_H);
liamg 0:91b1274ec397 184 zL=readByte(L3GD20_ADDR,gOUT_Z_L);
liamg 0:91b1274ec397 185 zH=readByte(L3GD20_ADDR,gOUT_Z_H);
liamg 0:91b1274ec397 186
liamg 0:91b1274ec397 187 gX=(xH<<8) | (xL); // 16-bit 2's complement data
liamg 0:91b1274ec397 188 gY=(yH<<8) | (yL);
liamg 0:91b1274ec397 189 gZ=(zH<<8) | (zL);
liamg 0:91b1274ec397 190
liamg 0:91b1274ec397 191 rorX=(float) gX * (17.5/1000.0); // At 500dps sensitivity, L3GD20 returns 17.5/1000 dps per digit
liamg 0:91b1274ec397 192 rorY=(float) gY * (17.5/1000.0);
liamg 0:91b1274ec397 193 rorZ=(float) gZ * (17.5/1000.0);
liamg 0:91b1274ec397 194
liamg 0:91b1274ec397 195 pc.printf("Rate of rotation (dps): X:%5.1f Y:%5.1f Z:%5.1f \n",rorX,rorY,rorZ);
liamg 0:91b1274ec397 196 //pc.printf("gX: %x gY: %x gZ: %x \n",gX,gY,gZ);
liamg 0:91b1274ec397 197
liamg 0:91b1274ec397 198 }
liamg 0:91b1274ec397 199
liamg 0:91b1274ec397 200 int main()
liamg 0:91b1274ec397 201 {
liamg 0:91b1274ec397 202 SensorState_t state;
liamg 0:91b1274ec397 203
liamg 0:91b1274ec397 204 initSensors();
liamg 0:91b1274ec397 205
liamg 0:91b1274ec397 206 while(1)
liamg 0:91b1274ec397 207 {
liamg 0:91b1274ec397 208 LPS331(state);
liamg 0:91b1274ec397 209 LSM303(&state);
liamg 0:91b1274ec397 210 L3GD20();
liamg 0:91b1274ec397 211
liamg 0:91b1274ec397 212 pc.printf("\n");
liamg 0:91b1274ec397 213 wait(.5);
liamg 0:91b1274ec397 214 }
liamg 0:91b1274ec397 215 }
liamg 0:91b1274ec397 216
liamg 0:91b1274ec397 217
liamg 0:91b1274ec397 218