Hello All,
I have been trying to use MPU6050 with TM4C129, with i2c communication. I previously used mpu6050 with CC3200 with which i was getting an update rate of approx 1800Hz for just retrieving the data from the sensor. But with the same code (and adding Wire.Module(x)), on TM4C129, i am getting very low refresh rate (approx 70 Hz). Is there anyway that i can sort this issue?
I am not able to understand the reason behind this,
Codes used are:
// acc and gyro are arrays which store raw data from sensor
void loop()
{
timer = micros();
mpu.i2cRead(MPU9150_ACCEL_XOUT_H,buffer,6); // Read 6 bytes of accelerometer data from MPU6050
mpu.extractAccData(acc);
mpu.i2cRead(MPU9150_GYRO_XOUT_H,buffer,6); // read 6 bytes of gyroscope data from MPU9150
mpu.extractGyroData(gyro);
timer = micros()-timer;
}
this code was in the main loop, related functions used are:
for i2c-
uint8_t MPU9150::i2cRead(uint8_t reg,uint8_t * data, uint8_t length,boolean fromCmps)
{
uint8_t i;
// Read data from MPU9150
Wire.beginTransmission(MPU_ADDRESS); // Initialize communication with MPU9150 on i2c bus (issue start condition)
Wire.write(reg); // Write the address of the register to i2c bus the where the data should be read from
Wire.endTransmission(); // End data transfer throught i2c bus
Wire.requestFrom((int)MPU_ADDRESS,(int) length); // Request length bytes of data from MPU9150
for(i =0; i<length; i++) // Till the length bytes of data is read
{
while(!Wire.available()) // Wait till data is available from MPU9150
{
}
*(data+i) = Wire.read(); // Fill the buffer with read data
}
return i;
}
void MPU9150::extractAccData(uint8_t * data)
{
// Extract acceleration information
// Data is given as 16 bits, big-endian, 2's compliment format
// Default accelearion resolution is +/- 2g
for(int i=0; i<3; i++) // For X,Y and Z axes
{
if((data[2*i] >> 7) == 0x01) // Whether data is positive or negetive
{
// If MSB of high byte is 1, data is negetive
data[2*i] = ~data[2*i]; // Find 2's compliment
data[2*i+1] = ~ data[2*i +1];
// Extract acceleration data
raw_acc[i] =(float) (((data[2*i] << 8) | data[2*i+1])+1); // Combine two bytes of data into one float values
raw_acc[i] /= -acc_res; // Devide by resoultion of the acceleration
}
else
{
// If data is positive
raw_acc[i] = (float)((data[2*i]<<8 )| data[2*i+1] ); // Combine two bytes of data into one float values
raw_acc[i] /= acc_res; // Devide by resoultion of the acceleration
}
}
}
