Hello, I am a graduate student working on a project,
and trying to make & test the IMU sensor (EV ICM-20689).
#include <Wire.h>
#define ADDRESS 0x68 // AD0 = 0 : 0x68, AD0 = 1 : 0x69
#define GYRO_CONFIG 0x1B
#define ACCEL_CONFIG 0x1C
#define ACCEL_XOUT_H 0x3B
#define ACCEL_YOUT_H 0x3D
#define ACCEL_ZOUT_H 0x3F
#define GYRO_XOUT_H 0x43
#define GYRO_YOUT_H 0x45
#define GYRO_ZOUT_H 0x47
#define PWR_MGMT_1 0x6B
#define PWR_MGMT_2 0x6C
byte rawAX[2], rawAY[2], rawAZ[2];
byte rawGX[2], rawGY[2], rawGZ[2];
float rawACCX, rawACCY, rawACCZ;
float rawGYROX, rawGYROY, rawGYROZ;
void setup() {
Serial.begin(9600);
Wire.begin();
Serial.println("Connecting to ICM-20689...");
// Power Management 1 setup
Wire.beginTransmission(ADDRESS);
Wire.write(PWR_MGMT_1);
Wire.write(0x01);
Wire.endTransmission();
// Power Management 2 setup
Wire.beginTransmission(ADDRESS);
Wire.write(PWR_MGMT_2);
Wire.write(0x00);
Wire.endTransmission();
// Accelerometer Configuration
Wire.beginTransmission(ADDRESS);
Wire.write(ACCEL_CONFIG);
Wire.write(0x00);
Wire.endTransmission();
// Gyroscope Configuration
Wire.beginTransmission(ADDRESS);
Wire.write(GYRO_CONFIG);
Wire.write(0x00);
Wire.endTransmission();
Serial.println(" Acc_X Acc_Y Acc_Z Gyro_X Gyro_Y Gyro_Z");
}
void loop() {
getACC();
Serial.print(rawACCX/16384, DEC); Serial.print('\t');
Serial.print(rawACCY/16384, DEC); Serial.print('\t');
Serial.print(rawACCZ/16384, DEC); Serial.print("\t\t");
getGYRO();
Serial.print(rawGYROX/131, DEC); Serial.print('\t');
Serial.print(rawGYROY/131, DEC); Serial.print('\t');
Serial.print(rawGYROZ/131, DEC);
Serial.println();
delay(100);
}
void getACC(){
Wire.beginTransmission(ADDRESS);
Wire.write(ACCEL_XOUT_H);
Wire.requestFrom(ADDRESS,2,1);
for(int i = 0; i<2 ; i++)
{
rawAX[i] = Wire.read();
}
// High + Low Byte
rawACCX = rawAX[1] | rawAX[0] <<8;
Wire.endTransmission();
Wire.beginTransmission(ADDRESS);
Wire.write(ACCEL_YOUT_H);
Wire.requestFrom(ADDRESS,2,1);
for(int i = 0; i<2 ; i++)
{
rawAY[i] = Wire.read();
}
rawACCY = rawAY[1] | rawAY[0]<<8;
Wire.endTransmission();
Wire.beginTransmission(ADDRESS);
Wire.write(ACCEL_ZOUT_H);
Wire.requestFrom(ADDRESS,2,1);
for(int i = 0; i<2 ; i++)
{
rawAZ[i] = Wire.read();
}
rawACCZ = rawAZ[1] | rawAZ[0]<<8;
Wire.endTransmission();
}
void getGYRO(){
Wire.beginTransmission(ADDRESS);
Wire.write(GYRO_XOUT_H);
Wire.requestFrom(ADDRESS,2,1);
for(int i = 0; i<2 ; i++)
{
rawGX[i] = Wire.read();
}
rawGYROX = rawGX[1] | rawGX[0]<<8;
Wire.endTransmission();
Wire.beginTransmission(ADDRESS);
Wire.write(GYRO_YOUT_H);
Wire.requestFrom(0x68,2,1);
for(int i = 0; i<2 ; i++)
{
rawGY[i] = Wire.read();
}
rawGYROY = rawGY[1] | rawGY[0]<<8;
Wire.endTransmission();
Wire.beginTransmission(ADDRESS);
Wire.write(GYRO_ZOUT_H);
Wire.requestFrom(0x68,2,1);
for(int i = 0; i<2 ; i++)
{
rawGZ[i] = Wire.read();
}
rawGYROZ = rawGZ[1] | rawGZ[0]<<8;
Wire.endTransmission();
}
I cannot find problem in my code,
but somehow it seems that 'Acc_X' and 'Gyro_X' result is shifted.
Attachment file 'Previous code.png' is the result of the upper code.
If I change the loop part by shifting the Gyro_X and Acc_X like below,
getACC();
Serial.print(rawGYROX/16384, DEC); Serial.print('\t');
Serial.print(rawACCY/16384, DEC); Serial.print('\t');
Serial.print(rawACCZ/16384, DEC); Serial.print("\t\t");
getGYRO();
Serial.print(rawACCX/131, DEC); Serial.print('\t');
Serial.print(rawGYROY/131, DEC); Serial.print('\t');
Serial.print(rawGYROZ/131, DEC);
the result changes like 'Changed code.png'
As I know, if I put the sensor vertically or horizontally, the acceleration result must be +/- 1 for each axis.
And if the sensor is stationary, the gyroscope result must be near zero.
So, it appears that two values(Acc_X & Gyro_X) are being shifted somehow.
I would like to get comments on this issue.
Is there a problem with my code?
Or is there a problem with the sensor?
ICM-20689-v2.2-002.pdf (761 KB)
