/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- #include #include "AP_InertialSensor_MPU6000.h" extern const AP_HAL::HAL& hal; // MPU6000 accelerometer scaling #define MPU6000_ACCEL_SCALE_1G (GRAVITY_MSS / 4096.0f) // MPU 6000 registers #define MPUREG_XG_OFFS_TC 0x00 #define MPUREG_YG_OFFS_TC 0x01 #define MPUREG_ZG_OFFS_TC 0x02 #define MPUREG_X_FINE_GAIN 0x03 #define MPUREG_Y_FINE_GAIN 0x04 #define MPUREG_Z_FINE_GAIN 0x05 #define MPUREG_XA_OFFS_H 0x06 // X axis accelerometer offset (high byte) #define MPUREG_XA_OFFS_L 0x07 // X axis accelerometer offset (low byte) #define MPUREG_YA_OFFS_H 0x08 // Y axis accelerometer offset (high byte) #define MPUREG_YA_OFFS_L 0x09 // Y axis accelerometer offset (low byte) #define MPUREG_ZA_OFFS_H 0x0A // Z axis accelerometer offset (high byte) #define MPUREG_ZA_OFFS_L 0x0B // Z axis accelerometer offset (low byte) #define MPUREG_PRODUCT_ID 0x0C // Product ID Register #define MPUREG_XG_OFFS_USRH 0x13 // X axis gyro offset (high byte) #define MPUREG_XG_OFFS_USRL 0x14 // X axis gyro offset (low byte) #define MPUREG_YG_OFFS_USRH 0x15 // Y axis gyro offset (high byte) #define MPUREG_YG_OFFS_USRL 0x16 // Y axis gyro offset (low byte) #define MPUREG_ZG_OFFS_USRH 0x17 // Z axis gyro offset (high byte) #define MPUREG_ZG_OFFS_USRL 0x18 // Z axis gyro offset (low byte) #define MPUREG_SMPLRT_DIV 0x19 // sample rate. Fsample= 1Khz/(+1) = 200Hz # define MPUREG_SMPLRT_1000HZ 0x00 # define MPUREG_SMPLRT_500HZ 0x01 # define MPUREG_SMPLRT_250HZ 0x03 # define MPUREG_SMPLRT_200HZ 0x04 # define MPUREG_SMPLRT_100HZ 0x09 # define MPUREG_SMPLRT_50HZ 0x13 #define MPUREG_CONFIG 0x1A #define MPUREG_GYRO_CONFIG 0x1B // bit definitions for MPUREG_GYRO_CONFIG # define BITS_GYRO_FS_250DPS 0x00 # define BITS_GYRO_FS_500DPS 0x08 # define BITS_GYRO_FS_1000DPS 0x10 # define BITS_GYRO_FS_2000DPS 0x18 # define BITS_GYRO_FS_MASK 0x18 // only bits 3 and 4 are used for gyro full scale so use this to mask off other bits # define BITS_GYRO_ZGYRO_SELFTEST 0x20 # define BITS_GYRO_YGYRO_SELFTEST 0x40 # define BITS_GYRO_XGYRO_SELFTEST 0x80 #define MPUREG_ACCEL_CONFIG 0x1C #define MPUREG_MOT_THR 0x1F // detection threshold for Motion interrupt generation. Motion is detected when the absolute value of any of the accelerometer measurements exceeds this #define MPUREG_MOT_DUR 0x20 // duration counter threshold for Motion interrupt generation. The duration counter ticks at 1 kHz, therefore MOT_DUR has a unit of 1 LSB = 1 ms #define MPUREG_ZRMOT_THR 0x21 // detection threshold for Zero Motion interrupt generation. #define MPUREG_ZRMOT_DUR 0x22 // duration counter threshold for Zero Motion interrupt generation. The duration counter ticks at 16 Hz, therefore ZRMOT_DUR has a unit of 1 LSB = 64 ms. #define MPUREG_FIFO_EN 0x23 #define MPUREG_INT_PIN_CFG 0x37 # define BIT_INT_RD_CLEAR 0x10 // clear the interrupt when any read occurs # define BIT_LATCH_INT_EN 0x20 // latch data ready pin #define MPUREG_INT_ENABLE 0x38 // bit definitions for MPUREG_INT_ENABLE # define BIT_RAW_RDY_EN 0x01 # define BIT_DMP_INT_EN 0x02 // enabling this bit (DMP_INT_EN) also enables RAW_RDY_EN it seems # define BIT_UNKNOWN_INT_EN 0x04 # define BIT_I2C_MST_INT_EN 0x08 # define BIT_FIFO_OFLOW_EN 0x10 # define BIT_ZMOT_EN 0x20 # define BIT_MOT_EN 0x40 # define BIT_FF_EN 0x80 #define MPUREG_INT_STATUS 0x3A // bit definitions for MPUREG_INT_STATUS (same bit pattern as above because this register shows what interrupt actually fired) # define BIT_RAW_RDY_INT 0x01 # define BIT_DMP_INT 0x02 # define BIT_UNKNOWN_INT 0x04 # define BIT_I2C_MST_INT 0x08 # define BIT_FIFO_OFLOW_INT 0x10 # define BIT_ZMOT_INT 0x20 # define BIT_MOT_INT 0x40 # define BIT_FF_INT 0x80 #define MPUREG_ACCEL_XOUT_H 0x3B #define MPUREG_ACCEL_XOUT_L 0x3C #define MPUREG_ACCEL_YOUT_H 0x3D #define MPUREG_ACCEL_YOUT_L 0x3E #define MPUREG_ACCEL_ZOUT_H 0x3F #define MPUREG_ACCEL_ZOUT_L 0x40 #define MPUREG_TEMP_OUT_H 0x41 #define MPUREG_TEMP_OUT_L 0x42 #define MPUREG_GYRO_XOUT_H 0x43 #define MPUREG_GYRO_XOUT_L 0x44 #define MPUREG_GYRO_YOUT_H 0x45 #define MPUREG_GYRO_YOUT_L 0x46 #define MPUREG_GYRO_ZOUT_H 0x47 #define MPUREG_GYRO_ZOUT_L 0x48 #define MPUREG_USER_CTRL 0x6A // bit definitions for MPUREG_USER_CTRL # define BIT_USER_CTRL_SIG_COND_RESET 0x01 // resets signal paths and results registers for all sensors (gyros, accel, temp) # define BIT_USER_CTRL_I2C_MST_RESET 0x02 // reset I2C Master (only applicable if I2C_MST_EN bit is set) # define BIT_USER_CTRL_FIFO_RESET 0x04 // Reset (i.e. clear) FIFO buffer # define BIT_USER_CTRL_DMP_RESET 0x08 // Reset DMP # define BIT_USER_CTRL_I2C_IF_DIS 0x10 // Disable primary I2C interface and enable hal.spi->interface # define BIT_USER_CTRL_I2C_MST_EN 0x20 // Enable MPU to act as the I2C Master to external slave sensors # define BIT_USER_CTRL_FIFO_EN 0x40 // Enable FIFO operations # define BIT_USER_CTRL_DMP_EN 0x80 // Enable DMP operations #define MPUREG_PWR_MGMT_1 0x6B # define BIT_PWR_MGMT_1_CLK_INTERNAL 0x00 // clock set to internal 8Mhz oscillator # define BIT_PWR_MGMT_1_CLK_XGYRO 0x01 // PLL with X axis gyroscope reference # define BIT_PWR_MGMT_1_CLK_YGYRO 0x02 // PLL with Y axis gyroscope reference # define BIT_PWR_MGMT_1_CLK_ZGYRO 0x03 // PLL with Z axis gyroscope reference # define BIT_PWR_MGMT_1_CLK_EXT32KHZ 0x04 // PLL with external 32.768kHz reference # define BIT_PWR_MGMT_1_CLK_EXT19MHZ 0x05 // PLL with external 19.2MHz reference # define BIT_PWR_MGMT_1_CLK_STOP 0x07 // Stops the clock and keeps the timing generator in reset # define BIT_PWR_MGMT_1_TEMP_DIS 0x08 // disable temperature sensor # define BIT_PWR_MGMT_1_CYCLE 0x20 // put sensor into cycle mode. cycles between sleep mode and waking up to take a single sample of data from active sensors at a rate determined by LP_WAKE_CTRL # define BIT_PWR_MGMT_1_SLEEP 0x40 // put sensor into low power sleep mode # define BIT_PWR_MGMT_1_DEVICE_RESET 0x80 // reset entire device #define MPUREG_PWR_MGMT_2 0x6C // allows the user to configure the frequency of wake-ups in Accelerometer Only Low Power Mode #define MPUREG_BANK_SEL 0x6D // DMP bank selection register (used to indirectly access DMP registers) #define MPUREG_MEM_START_ADDR 0x6E // DMP memory start address (used to indirectly write to dmp memory) #define MPUREG_MEM_R_W 0x6F // DMP related register #define MPUREG_DMP_CFG_1 0x70 // DMP related register #define MPUREG_DMP_CFG_2 0x71 // DMP related register #define MPUREG_FIFO_COUNTH 0x72 #define MPUREG_FIFO_COUNTL 0x73 #define MPUREG_FIFO_R_W 0x74 #define MPUREG_WHOAMI 0x75 // Configuration bits MPU 3000 and MPU 6000 (not revised)? #define BITS_DLPF_CFG_256HZ_NOLPF2 0x00 #define BITS_DLPF_CFG_188HZ 0x01 #define BITS_DLPF_CFG_98HZ 0x02 #define BITS_DLPF_CFG_42HZ 0x03 #define BITS_DLPF_CFG_20HZ 0x04 #define BITS_DLPF_CFG_10HZ 0x05 #define BITS_DLPF_CFG_5HZ 0x06 #define BITS_DLPF_CFG_2100HZ_NOLPF 0x07 #define BITS_DLPF_CFG_MASK 0x07 // Product ID Description for MPU6000 // high 4 bits low 4 bits // Product Name Product Revision #define MPU6000ES_REV_C4 0x14 // 0001 0100 #define MPU6000ES_REV_C5 0x15 // 0001 0101 #define MPU6000ES_REV_D6 0x16 // 0001 0110 #define MPU6000ES_REV_D7 0x17 // 0001 0111 #define MPU6000ES_REV_D8 0x18 // 0001 1000 #define MPU6000_REV_C4 0x54 // 0101 0100 #define MPU6000_REV_C5 0x55 // 0101 0101 #define MPU6000_REV_D6 0x56 // 0101 0110 #define MPU6000_REV_D7 0x57 // 0101 0111 #define MPU6000_REV_D8 0x58 // 0101 1000 #define MPU6000_REV_D9 0x59 // 0101 1001 /* * RM-MPU-6000A-00.pdf, page 33, section 4.25 lists LSB sensitivity of * gyro as 16.4 LSB/DPS at scale factor of +/- 2000dps (FS_SEL==3) */ const float AP_InertialSensor_MPU6000::_gyro_scale = (0.0174532f / 16.4f); /* * RM-MPU-6000A-00.pdf, page 31, section 4.23 lists LSB sensitivity of * accel as 4096 LSB/mg at scale factor of +/- 8g (AFS_SEL==2) * * See note below about accel scaling of engineering sample MPU6k * variants however */ AP_InertialSensor_MPU6000::AP_InertialSensor_MPU6000() : AP_InertialSensor(), _drdy_pin(NULL), _initialised(false), _mpu6000_product_id(AP_PRODUCT_ID_NONE) { } uint16_t AP_InertialSensor_MPU6000::_init_sensor( Sample_rate sample_rate ) { if (_initialised) return _mpu6000_product_id; _initialised = true; _spi = hal.spi->device(AP_HAL::SPIDevice_MPU6000); _spi_sem = _spi->get_semaphore(); /* Pin 70 defined especially to hook up PE6 to the hal.gpio abstraction. (It is not a valid pin under Arduino.) */ _drdy_pin = hal.gpio->channel(70); hal.scheduler->suspend_timer_procs(); uint8_t tries = 0; do { bool success = _hardware_init(sample_rate); if (success) { hal.scheduler->delay(5+2); if (!_spi_sem->take(100)) { hal.scheduler->panic(PSTR("MPU6000: Unable to get semaphore")); } if (_data_ready()) { _spi_sem->give(); break; } else { hal.console->println_P( PSTR("MPU6000 startup failed: no data ready")); } _spi_sem->give(); } if (tries++ > 5) { hal.scheduler->panic(PSTR("PANIC: failed to boot MPU6000 5 times")); } } while (1); hal.scheduler->resume_timer_procs(); /* read the first lot of data. * _read_data_transaction requires the spi semaphore to be taken by * its caller. */ _last_sample_time_micros = hal.scheduler->micros(); hal.scheduler->delay(10); if (_spi_sem->take(100)) { _read_data_transaction(); _spi_sem->give(); } // start the timer process to read samples hal.scheduler->register_timer_process(AP_HAL_MEMBERPROC(&AP_InertialSensor_MPU6000::_poll_data)); #if MPU6000_DEBUG _dump_registers(); #endif return _mpu6000_product_id; } /*================ AP_INERTIALSENSOR PUBLIC INTERFACE ==================== */ bool AP_InertialSensor_MPU6000::wait_for_sample(uint16_t timeout_ms) { if (_sample_available()) { return true; } uint32_t start = hal.scheduler->millis(); while ((hal.scheduler->millis() - start) < timeout_ms) { hal.scheduler->delay_microseconds(100); if (_sample_available()) { return true; } } return false; } bool AP_InertialSensor_MPU6000::update( void ) { // wait for at least 1 sample if (!wait_for_sample(1000)) { return false; } _previous_accel[0] = _accel[0]; // disable timer procs for mininum time hal.scheduler->suspend_timer_procs(); _gyro[0] = Vector3f(_gyro_sum.x, _gyro_sum.y, _gyro_sum.z); _accel[0] = Vector3f(_accel_sum.x, _accel_sum.y, _accel_sum.z); _num_samples = _sum_count; _accel_sum.zero(); _gyro_sum.zero(); _sum_count = 0; hal.scheduler->resume_timer_procs(); _gyro[0].rotate(_board_orientation); _gyro[0] *= _gyro_scale / _num_samples; _gyro[0] -= _gyro_offset[0]; _accel[0].rotate(_board_orientation); _accel[0] *= MPU6000_ACCEL_SCALE_1G / _num_samples; Vector3f accel_scale = _accel_scale[0].get(); _accel[0].x *= accel_scale.x; _accel[0].y *= accel_scale.y; _accel[0].z *= accel_scale.z; _accel[0] -= _accel_offset[0]; if (_last_filter_hz != _mpu6000_filter) { if (_spi_sem->take(10)) { _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_LOW); _set_filter_register(_mpu6000_filter, 0); _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_HIGH); _error_count = 0; _spi_sem->give(); } } return true; } /*================ HARDWARE FUNCTIONS ==================== */ /** * Return true if the MPU6000 has new data available for reading. * * We use the data ready pin if it is available. Otherwise, read the * status register. */ bool AP_InertialSensor_MPU6000::_data_ready() { if (_drdy_pin) { return _drdy_pin->read() != 0; } uint8_t status = _register_read(MPUREG_INT_STATUS); return (status & BIT_RAW_RDY_INT) != 0; } /** * Timer process to poll for new data from the MPU6000. */ void AP_InertialSensor_MPU6000::_poll_data(void) { if (hal.scheduler->in_timerprocess()) { if (!_spi_sem->take_nonblocking()) { /* the semaphore being busy is an expected condition when the mainline code is calling wait_for_sample() which will grab the semaphore. We return now and rely on the mainline code grabbing the latest sample. */ return; } if (_data_ready()) { _last_sample_time_micros = hal.scheduler->micros(); _read_data_transaction(); } _spi_sem->give(); } else { /* Synchronous read - take semaphore */ if (_spi_sem->take(10)) { if (_data_ready()) { _last_sample_time_micros = hal.scheduler->micros(); _read_data_transaction(); } _spi_sem->give(); } else { hal.scheduler->panic( PSTR("PANIC: AP_InertialSensor_MPU6000::_poll_data " "failed to take SPI semaphore synchronously")); } } } void AP_InertialSensor_MPU6000::_read_data_transaction() { /* one resister address followed by seven 2-byte registers */ struct PACKED { uint8_t cmd; uint8_t int_status; uint8_t v[14]; } rx, tx = { cmd : MPUREG_INT_STATUS | 0x80, }; _spi->transaction((const uint8_t *)&tx, (uint8_t *)&rx, sizeof(rx)); /* detect a bad SPI bus transaction by looking for all 14 bytes zero, or the wrong INT_STATUS register value. This is used to detect a too high SPI bus speed. */ uint8_t i; for (i=0; i<14; i++) { if (rx.v[i] != 0) break; } if ((rx.int_status&~0x6) != (_drdy_pin==NULL?0:BIT_RAW_RDY_INT) || i == 14) { // likely a bad bus transaction if (++_error_count > 4) { _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_LOW); } } #define int16_val(v, idx) ((int16_t)(((uint16_t)v[2*idx] << 8) | v[2*idx+1])) _accel_sum.x += int16_val(rx.v, 1); _accel_sum.y += int16_val(rx.v, 0); _accel_sum.z -= int16_val(rx.v, 2); _gyro_sum.x += int16_val(rx.v, 5); _gyro_sum.y += int16_val(rx.v, 4); _gyro_sum.z -= int16_val(rx.v, 6); _sum_count++; if (_sum_count == 0) { // rollover - v unlikely _accel_sum.zero(); _gyro_sum.zero(); } } uint8_t AP_InertialSensor_MPU6000::_register_read( uint8_t reg ) { uint8_t addr = reg | 0x80; // Set most significant bit uint8_t tx[2]; uint8_t rx[2]; tx[0] = addr; tx[1] = 0; _spi->transaction(tx, rx, 2); return rx[1]; } void AP_InertialSensor_MPU6000::_register_write(uint8_t reg, uint8_t val) { uint8_t tx[2]; uint8_t rx[2]; tx[0] = reg; tx[1] = val; _spi->transaction(tx, rx, 2); } /* set the DLPF filter frequency. Assumes caller has taken semaphore */ void AP_InertialSensor_MPU6000::_set_filter_register(uint8_t filter_hz, uint8_t default_filter) { uint8_t filter = default_filter; // choose filtering frequency switch (filter_hz) { case 5: filter = BITS_DLPF_CFG_5HZ; break; case 10: filter = BITS_DLPF_CFG_10HZ; break; case 20: filter = BITS_DLPF_CFG_20HZ; break; case 42: filter = BITS_DLPF_CFG_42HZ; break; case 98: filter = BITS_DLPF_CFG_98HZ; break; } if (filter != 0) { _last_filter_hz = filter_hz; _register_write(MPUREG_CONFIG, filter); } } bool AP_InertialSensor_MPU6000::_hardware_init(Sample_rate sample_rate) { if (!_spi_sem->take(100)) { hal.scheduler->panic(PSTR("MPU6000: Unable to get semaphore")); } // initially run the bus at low speed (500kHz on APM2) _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_LOW); // Chip reset uint8_t tries; for (tries = 0; tries<5; tries++) { _register_write(MPUREG_PWR_MGMT_1, BIT_PWR_MGMT_1_DEVICE_RESET); hal.scheduler->delay(100); // Wake up device and select GyroZ clock. Note that the // MPU6000 starts up in sleep mode, and it can take some time // for it to come out of sleep _register_write(MPUREG_PWR_MGMT_1, BIT_PWR_MGMT_1_CLK_ZGYRO); hal.scheduler->delay(5); // check it has woken up if (_register_read(MPUREG_PWR_MGMT_1) == BIT_PWR_MGMT_1_CLK_ZGYRO) { break; } #if MPU6000_DEBUG _dump_registers(); #endif } if (tries == 5) { hal.console->println_P(PSTR("Failed to boot MPU6000 5 times")); _spi_sem->give(); return false; } _register_write(MPUREG_PWR_MGMT_2, 0x00); // only used for wake-up in accelerometer only low power mode hal.scheduler->delay(1); // Disable I2C bus (recommended on datasheet) _register_write(MPUREG_USER_CTRL, BIT_USER_CTRL_I2C_IF_DIS); hal.scheduler->delay(1); uint8_t default_filter; // sample rate and filtering // to minimise the effects of aliasing we choose a filter // that is less than half of the sample rate switch (sample_rate) { case RATE_50HZ: // this is used for plane and rover, where noise resistance is // more important than update rate. Tests on an aerobatic plane // show that 10Hz is fine, and makes it very noise resistant default_filter = BITS_DLPF_CFG_10HZ; _sample_shift = 2; break; case RATE_100HZ: default_filter = BITS_DLPF_CFG_20HZ; _sample_shift = 1; break; case RATE_200HZ: default: default_filter = BITS_DLPF_CFG_20HZ; _sample_shift = 0; break; } _set_filter_register(_mpu6000_filter, default_filter); // set sample rate to 200Hz, and use _sample_divider to give // the requested rate to the application _register_write(MPUREG_SMPLRT_DIV, MPUREG_SMPLRT_200HZ); hal.scheduler->delay(1); _register_write(MPUREG_GYRO_CONFIG, BITS_GYRO_FS_2000DPS); // Gyro scale 2000ยบ/s hal.scheduler->delay(1); // read the product ID rev c has 1/2 the sensitivity of rev d _mpu6000_product_id = _register_read(MPUREG_PRODUCT_ID); //Serial.printf("Product_ID= 0x%x\n", (unsigned) _mpu6000_product_id); if ((_mpu6000_product_id == MPU6000ES_REV_C4) || (_mpu6000_product_id == MPU6000ES_REV_C5) || (_mpu6000_product_id == MPU6000_REV_C4) || (_mpu6000_product_id == MPU6000_REV_C5)) { // Accel scale 8g (4096 LSB/g) // Rev C has different scaling than rev D _register_write(MPUREG_ACCEL_CONFIG,1<<3); } else { // Accel scale 8g (4096 LSB/g) _register_write(MPUREG_ACCEL_CONFIG,2<<3); } hal.scheduler->delay(1); // configure interrupt to fire when new data arrives _register_write(MPUREG_INT_ENABLE, BIT_RAW_RDY_EN); hal.scheduler->delay(1); // clear interrupt on any read, and hold the data ready pin high // until we clear the interrupt _register_write(MPUREG_INT_PIN_CFG, BIT_INT_RD_CLEAR | BIT_LATCH_INT_EN); // now that we have initialised, we set the SPI bus speed to high // (8MHz on APM2) _spi->set_bus_speed(AP_HAL::SPIDeviceDriver::SPI_SPEED_HIGH); _spi_sem->give(); return true; } // return the MPU6k gyro drift rate in radian/s/s // note that this is much better than the oilpan gyros float AP_InertialSensor_MPU6000::get_gyro_drift_rate(void) { // 0.5 degrees/second/minute return ToRad(0.5/60); } // return true if a sample is available bool AP_InertialSensor_MPU6000::_sample_available() { _poll_data(); return (_sum_count >> _sample_shift) > 0; } #if MPU6000_DEBUG // dump all config registers - used for debug void AP_InertialSensor_MPU6000::_dump_registers(void) { hal.console->println_P(PSTR("MPU6000 registers")); for (uint8_t reg=MPUREG_PRODUCT_ID; reg<=108; reg++) { uint8_t v = _register_read(reg); hal.console->printf_P(PSTR("%02x:%02x "), (unsigned)reg, (unsigned)v); if ((reg - (MPUREG_PRODUCT_ID-1)) % 16 == 0) { hal.console->println(); } } hal.console->println(); } #endif // get_delta_time returns the time period in seconds overwhich the sensor data was collected float AP_InertialSensor_MPU6000::get_delta_time() { // the sensor runs at 200Hz return 0.005 * _num_samples; }