kriswiner
commented
7 years ago Self test is just a diagnostic, uses only LSbyte see attached.
On Fri, Nov 17, 2017 at 5:53 AM, aripod notifications@github.com wrote:
Hello Kris,
First of all thank you very much for such big effort and in advanced for taking the time to answer this.
I have ported your code to a Zynq FPGA:
void I2C_Write(XIicPs *Iic, unsigned char Address, unsigned char Register, unsigned char Value) { unsigned char u8TxData[2]; u8TxData[0] = Register; u8TxData[1] = Value; XIicPs_MasterSendPolled(Iic, u8TxData, 2, Address); }
void I2C_read(XIicPs Iic, unsigned char Address, unsigned char Register, unsigned char Bytes, unsigned char Data) { unsigned char u8TxData[1]; u8TxData[0] = Register; XIicPs_MasterSendPolled(Iic, u8TxData, 1, Address); while(XIicPs_BusIsBusy(Iic)); usleep(50000); XIicPs_MasterRecvPolled(Iic, Data, Bytes, Address); }
void MPU9250_SelfTest(XIicPs Iic, float result) { // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass int i; uint8_t rawData[6] = {0, 0, 0, 0, 0, 0}; uint8_t selfTest[6]; int32_t gAvg[3] = {0}, aAvg[3] = {0}, aSTAvg[3] = {0}, gSTAvg[3] = {0}; float factoryTrim[6]; uint8_t FS = 0;
I2C_Write(Iic, MPU9250_ADDR, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz. I2C_Write(Iic, MPU9250_ADDR, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz. I2C_Write(Iic, MPU9250_ADDR, GYRO_CONFIG, FS<<3); // Set full scale range for the gyro to 250 dps. I2C_Write(Iic, MPU9250_ADDR, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz. I2C_Write(Iic, MPU9250_ADDR, ACCEL_CONFIG, 0x00); // Set full scale range for the accelerometer to 2 g.
// Get average current values of Acclerometer and Gyroscope. for(i=0; i<200; i++) { I2C_read(Iic, MPU9250_ADDR, ACCEL_XOUT_H, 6, rawData); // Read the six Acc raw data registers into data array. aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
I2C_read(Iic, MPU9250_ADDR, GYRO_XOUT_H, 6, rawData); // Read the six Gyro raw data registers into data array. gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;} // Get average of 200 values and store as average current readings. for(i=0; i<3; i++) { aAvg[i] /= 200; gAvg[i] /= 200; }
// Configure the Accelerometer and Gyroscope for self-test. I2C_Write(Iic, MPU9250_ADDR, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g. I2C_Write(Iic, MPU9250_ADDR, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s. usleep(25000); // Delay a while to let the device stabilize. // Get average current values of Accelerometer and Gyroscope. for(i=0; i<200; i++) { I2C_read(Iic, MPU9250_ADDR, ACCEL_XOUT_H, 6, rawData); // Read the six Acc raw data registers into data array. aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
I2C_read(Iic, MPU9250_ADDR, GYRO_XOUT_H, 6, rawData); // Read the six Gyro raw data registers into data array. gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ; gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;} // Get average of 200 values and store as average current readings. for(i=0; i<3; i++) { aSTAvg[i] /= 200; gSTAvg[i] /= 200; }
// Configure the Accelerometer and Gyroscope for normal operation. I2C_Write(Iic, MPU9250_ADDR, ACCEL_CONFIG, 0x00); I2C_Write(Iic, MPU9250_ADDR, GYRO_CONFIG, 0x00); usleep(25000); // Delay a while to let the device stabilize.
// Retrieve accelerometer and gyroscope factory Self-Test Code from USR_Reg. I2C_read(Iic, MPU9250_ADDR, SELF_TEST_X_ACCEL, 1, &selfTest[0]); // X-axis accel self-test results. I2C_read(Iic, MPU9250_ADDR, SELF_TEST_Y_ACCEL, 1, &selfTest[1]); // Y-axis accel self-test results. I2C_read(Iic, MPU9250_ADDR, SELF_TEST_Z_ACCEL, 1, &selfTest[2]); // Z-axis accel self-test results. I2C_read(Iic, MPU9250_ADDR, SELF_TEST_X_GYRO, 1, &selfTest[3]); // X-axis gyro self-test results. I2C_read(Iic, MPU9250_ADDR, SELF_TEST_Y_GYRO, 1, &selfTest[4]); // Y-axis gyro self-test results. I2C_read(Iic, MPU9250_ADDR, SELF_TEST_Z_GYRO, 1, &selfTest[5]); // Z-axis gyro self-test results.
// Retrieve factory self-test value from self-test code reads. factoryTrim[0] = (float)(2620/1<<FS)(pow( 1.01 , ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation factoryTrim[1] = (float)(2620/1<<FS)(pow( 1.01 , ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation factoryTrim[2] = (float)(2620/1<<FS)(pow( 1.01 , ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation factoryTrim[3] = (float)(2620/1<<FS)(pow( 1.01 , ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation factoryTrim[4] = (float)(2620/1<<FS)(pow( 1.01 , ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation factoryTrim[5] = (float)(2620/1<<FS)(pow( 1.01 , ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation
// Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response // To get percent, must multiply by 100 for (i = 0; i < 3; i++) { result[i] = 100.0((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i] - 100.; // Report percent differences result[i+3] = 100.0((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3] - 100.; // Report percent differences } }
I tested the communication (like you) and I get the values that I should receive. The result of the self test is the following:
[MPU9250] Read value in reg 0x75 is 0x71. It should be 0x71. selfTest: [Ax, Ay, Az] = [-79.-388%, -98.-27%, -58.-327%] - [Gx, Gy, Gz] = [-77.-833%, -60.-471%, -82.-575%]
Should I trust the device? Or this would be fixed after the calibration? I have double checked the code and it is like yours...I believe I am getting the proper values from the chip. What do you think?
Thank you very much for your help.
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aripod
shomedas
Hello Kris,
First of all thank you very much for such big effort and in advanced for taking the time to answer this.
I have ported your code to a Zynq FPGA:
I tested the communication (like you) and I get the values that I should receive. The result of the self test is the following (terminal output):
I run this a few times and the average value does not differ from these numbers.
Should I trust the device? Or this would be fixed after the calibration? I have double checked the code and it is like yours...I believe I am getting the proper values from the chip. What do you think?
One other thing is that when I check if there is new data with the INT_STATUS register, I need to add a 50us delay before I read the values from the accelerometer and gyroscope. Otherwise, I get their maximum value on all 6 registers....
Thank you very much for your help.