Files
stm32uav/mpu6050.c
2022-09-27 20:01:14 +02:00

197 lines
5.4 KiB
C

/*
* Copyright 2022 Oleg Borodin <borodin@unix7.org>
*/
#include <libopencm3/stm32/i2c.h>
#include <stdint.h>
#include <math.h>
#include <i2cdev.h>
#include <mpu6050.h>
#define MPU_REG_SMPLRT_DIV 0x19
#define MPU_REG_CONFIG 0x1A
#define MPU_REG_GYRO_CONFIG 0x1B
#define MPU_REG_ACCEL_CONFIG 0x1C
#define MPU_REG_ACCEL_XOUT_H 0x3B
#define MPU_REG_ACCEL_XOUT_L 0x3C
#define MPU_REG_ACCEL_YOUT_H 0x3D
#define MPU_REG_ACCEL_YOUT_L 0x3E
#define MPU_REG_ACCEL_ZOUT_H 0x3F
#define MPU_REG_ACCEL_ZOUT_L 0x40
#define MPU_REG_TEMP_OUT_H 0x41
#define MPU_REG_TEMP_OUT_L 0x42
#define MPU_REG_GYRO_XOUT_H 0x43
#define MPU_REG_GYRO_XOUT_L 0x44
#define MPU_REG_GYRO_YOUT_H 0x45
#define MPU_REG_GYRO_YOUT_L 0x46
#define MPU_REG_GYRO_ZOUT_H 0x47
#define MPU_REG_GYRO_ZOUT_L 0x48
#define MPU_REG_PWR_MGMT_1 0x6B
#define MPU_REG_PWR_MGMT_2 0x6C
/* GYRO_CONFIG 0x1B */
#define MPU_GYRO_FS_BASE 3
#define MPU_GYRO_FS_LEN 2
#define MPU_GYRO_FS_250 0
#define MPU_GYRO_FS_500 1
#define MPU_GYRO_FS_1000 2
#define MPU_GYRO_FS_2000 3
/* ACCEL_CONFIG 0x1C */
#define MPU_ACCEL_FS_BASE 3
#define MPU_ACCEL_FS_LEN 2
#define MPU_ACCEL_FS_2 0
#define MPU_ACCEL_FS_4 1
#define MPU_ACCEL_FS_8 2
#define MPU_ACCEL_FS_16 3
#define MPU_GYRO_LSB_250 131.0f
#define MPU_GYRO_LSB_500 65.5f
#define MPU_GYRO_LSB_1000 32.8f
#define MPU_GYRO_LSB_2000 16.4f
#define MPU_ACCEL_LSB_2 16384.0f
#define MPU_ACCEL_LSB_4 8192.0f
#define MPU_ACCEL_LSB_8 4096.0f
#define MPU_ACCEL_LSB_16 2048.0f
/* PWR_MGMT_1 0x6B */
#define MPU_PWR1_DEVICE_RESET_BIT 7
#define MPU_PWR1_SLEEP_BIT 6
#define MPU_PWR1_CYCLE_BIT 5
#define MPU_PWR1_TEMP_DIS_BIT 3
#define MPU_PWR1_CLKSEL_BASE 0
#define MPU_PWR1_CLKSEL_LEN 3
#define MPU_PWR1_CLKSEL_INTERNAL 0
#define MPU_PWR1_CLKSEL_PLL_XGYRO 1
#define MPU_PWR1_CLKSEL_PLL_YGYRO 2
#define MPU_PWR1_CLKSEL_PLL_ZGYRO 3
#define MPU_PWR1_CLKSEL_PLL_EXT32K 4
#define MPU_PWR1_CLKSEL_PLL_EXT19M 5
#define MPU_PWR1_CLKSEL_KEEP_RESET 7
/* PWR_MGMT_2 0x6C */
#define MPU_PWR2_LP_WAKE_CTRL_BASE 6
#define MPU_PWR2_LP_WAKE_CTRL_LEN 2
#define MPU_PWR2_WAKE_FREQ_1P25 0
#define MPU_PWR2_WAKE_FREQ_2P5 1
#define MPU_PWR2_WAKE_FREQ_5 2
#define MPU_PWR2_WAKE_FREQ_10 3
#define MPU_PWR2_STBY_XA_BIT 5
#define MPU_PWR2_STBY_YA_BIT 4
#define MPU_PWR2_STBY_ZA_BIT 3
#define MPU_PWR2_STBY_XG_BIT 2
#define MPU_PWR2_STBY_YG_BIT 1
#define MPU_PWR2_STBY_ZG_BIT 0
#define MPU_GYRO_LSB MPU_GYRO_LSB_1000
#define MPU_GYRO_FS MPU_GYRO_FS_1000
#define MPU_ACCEL_LSB MPU_ACCEL_LSB_16
#define MPU_ACCEL_FS MPU_ACCEL_FS_16
void imu_setup(imu_t* imu, uint32_t i2c, uint8_t addr) {
imu->bus = i2c;
imu->addr = addr;
imu->gxe = 0;
imu->gye = 0;
imu->gze = 0;
//i2cdev_write_reg8(i2c, addr, MPU_REG_PWR_MGMT_1, 1 << MPU_PWR1_DEVICE_RESET_BIT);
//for (int i = 0; i < 10000; i++) __asm__("nop");
i2cdev_write_reg8(i2c, addr, MPU_REG_PWR_MGMT_1, 0x00);
i2cdev_write_reg8(i2c, addr, MPU_REG_GYRO_CONFIG, MPU_GYRO_FS << MPU_GYRO_FS_BASE);
i2cdev_write_reg8(i2c, addr, MPU_REG_ACCEL_CONFIG, MPU_ACCEL_FS << MPU_ACCEL_FS_BASE);
i2cdev_write_reg8(i2c, addr, MPU_REG_SMPLRT_DIV, 4);
}
static void imu_rawread(imu_t* imu, imuvec_t* val) {
uint8_t buffer[14];
i2cdev_read_seq8(imu->bus, imu->addr, MPU_REG_ACCEL_XOUT_H, (uint8_t*)buffer, 14);
int16_t ax = (((int16_t)buffer[0]) << 8) | buffer[1];
int16_t ay = (((int16_t)buffer[2]) << 8) | buffer[3];
int16_t az = (((int16_t)buffer[4]) << 8) | buffer[5];
int16_t gx = (((int16_t)buffer[8]) << 8) | buffer[9];
int16_t gy = (((int16_t)buffer[10]) << 8) | buffer[11];
int16_t gz = (((int16_t)buffer[12]) << 8) | buffer[13];
val->ax = (double)ax / (double)MPU_ACCEL_LSB;
val->ay = (double)ay / (double)MPU_ACCEL_LSB;
val->az = (double)az / (double)MPU_ACCEL_LSB;
val->gx = (double)gx / (double)MPU_GYRO_LSB;
val->gy = (double)gy / (double)MPU_GYRO_LSB;
val->gz = (double)gz / (double)MPU_GYRO_LSB;
val->gx *= M_PI / 180.0;
val->gy *= M_PI / 180.0;
val->gz *= M_PI / 180.0;
}
void imu_calibrate(imu_t* imu, int loops) {
imuvec_t val;
val.ax = 0;
val.ay = 0;
val.az = 0;
val.gx = 0;
val.gy = 0;
val.gz = 0;
for (int i = 0; i < loops; i++) {
imu_rawread(imu, &val);
imu->gxe += val.gx / (double)loops;
imu->gye += val.gy / (double)loops;
imu->gze += val.gz / (double)loops;
}
}
void imu_gettilt(imu_t* imu, int loops, eulerangle_t* a) {
imuvec_t val;
val.ax = 0;
val.ay = 0;
val.az = 0;
val.gx = 0;
val.gy = 0;
val.gz = 0;
double ax = 0;
double ay = 0;
double az = 0;
for (int i = 0; i < loops; i++) {
imu_rawread(imu, &val);
ax += val.ax / (double)loops;
ay += val.ay / (double)loops;
az += val.az / (double)loops;
}
a->x = atan(ax / sqrt(ay*ay + az*az));
a->y = atan(ay / sqrt(ax*ax + az*az));
a->z = atan(az / sqrt(ax*ax + ay*ay));
}
void imu_getvec(imu_t* imu, imuvec_t* val) {
imu_rawread(imu, val);
val->gx -= imu->gxe;
val->gy -= imu->gye;
val->gz -= imu->gze;
}