Successful acro and level mode now! Relying on MPU9250 as base sensor. I'm working continuously on tuning and features :) NEWEST VERSION ON: https://github.com/MaEtUgR/FlyBed (CODE 100% compatible/copyable)
IMU/MPU9250/MPU9250.cpp
- Committer:
- maetugr
- Date:
- 2015-11-19
- Revision:
- 8:609a2ad4c30e
- Parent:
- 5:8ea99e98de73
File content as of revision 8:609a2ad4c30e:
#include "MPU9250.h" MPU9250::MPU9250(PinName MOSI, PinName MISO, PinName SCLK, PinName CS) : spi(MOSI, MISO, SCLK), cs(CS) { deselect(); // chip must be deselected first spi.format(8,0); // setup the spi for standard 8 bit data and SPI-Mode 0 spi.frequency(5e6); // with a 5MHz clock rate /* last 3 Bits of|Accelerometer(Fs=1kHz) |Gyroscope MPU9250_CONFIG|Bandwidth(Hz)|Delay(ms)|Bandwidth(Hz)|Delay(ms)|Fs(kHz) ------------------------------------------------------------------------- 0 |260 |0 |256 |0.98 |8 1 |184 |2.0 |188 |1.9 |1 2 |94 |3.0 |98 |2.8 |1 3 |44 |4.9 |42 |4.8 |1 4 |21 |8.5 |20 |8.3 |1 5 |10 |13.8 |10 |13.4 |1 6 |5 |19.0 |5 |18.6 |1 */ writeRegister8(MPU9250_CONFIG, 0x00); writeRegister8(MPU9250_GYRO_CONFIG, 0x18); // scales gyros range to +-2000dps writeRegister8(MPU9250_ACCEL_CONFIG, 0x08); // scales accelerometers range to +-4g } uint8_t MPU9250::getWhoami() { return readRegister8(MPU9250_WHO_AM_I); } float MPU9250::getTemperature() { int16_t data = readRegister16(MPU9250_TEMP_OUT_H); return ((data - 21) / 333.87) + 21; // formula from register map p.33 } void MPU9250::readGyro() { int16_t rawGyro[3]; readRegister48(MPU9250_GYRO_XOUT_H, rawGyro); int16_t offsetGyro[3] = {-31, -16, -12}; // TODO: make better calibration for (int i = 0; i < 3; i++) Gyro[i] = (rawGyro[i] - offsetGyro[i]) * 0.07 * 0.87; // subtract offset from calibration and multiply unit factor to get degree per second (datasheet p.10) float tmp = Gyro[0]; Gyro[0] = -Gyro[1]; Gyro[1] = -tmp; Gyro[2] = -Gyro[2]; } void MPU9250::readAcc() { int16_t rawAcc[3]; readRegister48(MPU9250_ACCEL_XOUT_H, rawAcc); int16_t offsetAcc[3] = {-120, -48, -438}; // TODO: make better calibration for (int i = 0; i < 3; i++) Acc[i] = (rawAcc[i] - offsetAcc[i])/8192.0; // TODO: didn't care about units because IMU-algorithm just uses vector direction float tmp = Acc[0]; Acc[0] = -Acc[1]; Acc[1] = -tmp; Acc[2] = -Acc[2]; } // PRIVATE Methods ------------------------------------------------------------------------------------ // SPI Interface -------------------------------------------------------------------------------------- uint8_t MPU9250::readRegister8(uint8_t reg) { uint8_t result; readRegister(reg, &result, 1); return result; } uint16_t MPU9250::readRegister16(uint8_t reg) { uint8_t result[2]; readRegister(reg, result, 2); return result[0]<<8 | result[1]; // join 8-Bit pieces to 16-bit short integer } void MPU9250::readRegister48(uint8_t reg, int16_t *buffer) { uint8_t result[6]; readRegister(reg, result, 6); buffer[0] = (int16_t) (result[0] << 8 | result[1]); // join 8-Bit pieces to 16-bit short integers buffer[1] = (int16_t) (result[2] << 8 | result[3]); buffer[2] = (int16_t) (result[4] << 8 | result[5]); } void MPU9250::writeRegister8(uint8_t reg, uint8_t buffer) { writeRegister(reg, &buffer, 1); } void MPU9250::readRegister(uint8_t reg, uint8_t *buffer, int length) { select(); spi.write(reg | 0x80); // send the register address we want to read and the read flag for(int i=0; i<length; i++) // get data buffer[i] = spi.write(0x00); deselect(); } void MPU9250::writeRegister(uint8_t reg, uint8_t *buffer, int length) { select(); spi.write(reg & ~0x80); // send the register address we want to write and the write flag for(int i=0; i<length; i++) // put data spi.write(buffer[i]); deselect(); } void MPU9250::select() { cs = 0; } // set Cable Select pin low to start SPI transaction void MPU9250::deselect() { cs = 1; } // set Cable Select pin high to stop SPI transaction