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author | Andrew Tridgell <andrew@tridgell.net> | 2014-12-24 12:56:10 -0800 |
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committer | Thomas Gubler <thomasgubler@gmail.com> | 2014-12-30 20:55:57 +0100 |
commit | 3e06a65516697c6bdf840d8104328ad09c0ccfbd (patch) | |
tree | 5e1fa1e71f26af5d904d334d3ba5b1e03e173785 /src/drivers/mpu6000/mpu6000.cpp | |
parent | 75bff509c460c66868c5867ac10ffc8b077d34f6 (diff) | |
download | px4-firmware-3e06a65516697c6bdf840d8104328ad09c0ccfbd.tar.gz px4-firmware-3e06a65516697c6bdf840d8104328ad09c0ccfbd.tar.bz2 px4-firmware-3e06a65516697c6bdf840d8104328ad09c0ccfbd.zip |
mpu6000: monitor some key registers for correct values
this will catch both bad SPI bus comms and a sensor that has been
reset causing incorrect configuration.
Diffstat (limited to 'src/drivers/mpu6000/mpu6000.cpp')
-rw-r--r-- | src/drivers/mpu6000/mpu6000.cpp | 142 |
1 files changed, 132 insertions, 10 deletions
diff --git a/src/drivers/mpu6000/mpu6000.cpp b/src/drivers/mpu6000/mpu6000.cpp index c9c27892f..3d720cd94 100644 --- a/src/drivers/mpu6000/mpu6000.cpp +++ b/src/drivers/mpu6000/mpu6000.cpp @@ -231,8 +231,11 @@ private: perf_counter_t _gyro_reads; perf_counter_t _sample_perf; perf_counter_t _bad_transfers; + perf_counter_t _bad_registers; perf_counter_t _good_transfers; + uint8_t _register_wait; + math::LowPassFilter2p _accel_filter_x; math::LowPassFilter2p _accel_filter_y; math::LowPassFilter2p _accel_filter_z; @@ -242,6 +245,14 @@ private: enum Rotation _rotation; + // this is used to support runtime checking of key + // configuration registers to detect SPI bus errors and sensor + // reset +#define MPU6000_NUM_CHECKED_REGISTERS 4 + static const uint8_t _checked_registers[MPU6000_NUM_CHECKED_REGISTERS]; + uint8_t _checked_values[MPU6000_NUM_CHECKED_REGISTERS]; + uint8_t _checked_next; + /** * Start automatic measurement. */ @@ -281,7 +292,7 @@ private: * @param The register to read. * @return The value that was read. */ - uint8_t read_reg(unsigned reg); + uint8_t read_reg(unsigned reg, uint32_t speed=MPU6000_LOW_BUS_SPEED); uint16_t read_reg16(unsigned reg); /** @@ -304,6 +315,14 @@ private: void modify_reg(unsigned reg, uint8_t clearbits, uint8_t setbits); /** + * Write a register in the MPU6000, updating _checked_values + * + * @param reg The register to write. + * @param value The new value to write. + */ + void write_checked_reg(unsigned reg, uint8_t value); + + /** * Set the MPU6000 measurement range. * * @param max_g The maximum G value the range must support. @@ -347,11 +366,26 @@ private: */ void _set_sample_rate(uint16_t desired_sample_rate_hz); + /* + check that key registers still have the right value + */ + void check_registers(void); + /* do not allow to copy this class due to pointer data members */ MPU6000(const MPU6000&); MPU6000 operator=(const MPU6000&); }; +/* + list of registers that will be checked in check_registers(). Note + that MPUREG_PRODUCT_ID must be first in the list. + */ +const uint8_t MPU6000::_checked_registers[MPU6000_NUM_CHECKED_REGISTERS] = { MPUREG_PRODUCT_ID, + MPUREG_GYRO_CONFIG, + MPUREG_ACCEL_CONFIG, + MPUREG_USER_CTRL }; + + /** * Helper class implementing the gyro driver node. */ @@ -407,14 +441,17 @@ MPU6000::MPU6000(int bus, const char *path_accel, const char *path_gyro, spi_dev _gyro_reads(perf_alloc(PC_COUNT, "mpu6000_gyro_read")), _sample_perf(perf_alloc(PC_ELAPSED, "mpu6000_read")), _bad_transfers(perf_alloc(PC_COUNT, "mpu6000_bad_transfers")), + _bad_registers(perf_alloc(PC_COUNT, "mpu6000_bad_registers")), _good_transfers(perf_alloc(PC_COUNT, "mpu6000_good_transfers")), + _register_wait(0), _accel_filter_x(MPU6000_ACCEL_DEFAULT_RATE, MPU6000_ACCEL_DEFAULT_DRIVER_FILTER_FREQ), _accel_filter_y(MPU6000_ACCEL_DEFAULT_RATE, MPU6000_ACCEL_DEFAULT_DRIVER_FILTER_FREQ), _accel_filter_z(MPU6000_ACCEL_DEFAULT_RATE, MPU6000_ACCEL_DEFAULT_DRIVER_FILTER_FREQ), _gyro_filter_x(MPU6000_GYRO_DEFAULT_RATE, MPU6000_GYRO_DEFAULT_DRIVER_FILTER_FREQ), _gyro_filter_y(MPU6000_GYRO_DEFAULT_RATE, MPU6000_GYRO_DEFAULT_DRIVER_FILTER_FREQ), _gyro_filter_z(MPU6000_GYRO_DEFAULT_RATE, MPU6000_GYRO_DEFAULT_DRIVER_FILTER_FREQ), - _rotation(rotation) + _rotation(rotation), + _checked_next(0) { // disable debug() calls _debug_enabled = false; @@ -460,6 +497,7 @@ MPU6000::~MPU6000() perf_free(_accel_reads); perf_free(_gyro_reads); perf_free(_bad_transfers); + perf_free(_bad_registers); perf_free(_good_transfers); } @@ -590,7 +628,7 @@ void MPU6000::reset() up_udelay(1000); // Disable I2C bus (recommended on datasheet) - write_reg(MPUREG_USER_CTRL, BIT_I2C_IF_DIS); + write_checked_reg(MPUREG_USER_CTRL, BIT_I2C_IF_DIS); irqrestore(state); usleep(1000); @@ -605,7 +643,7 @@ void MPU6000::reset() _set_dlpf_filter(MPU6000_DEFAULT_ONCHIP_FILTER_FREQ); usleep(1000); // Gyro scale 2000 deg/s () - write_reg(MPUREG_GYRO_CONFIG, BITS_FS_2000DPS); + write_checked_reg(MPUREG_GYRO_CONFIG, BITS_FS_2000DPS); usleep(1000); // correct gyro scale factors @@ -624,7 +662,7 @@ void MPU6000::reset() case MPU6000_REV_C5: // Accel scale 8g (4096 LSB/g) // Rev C has different scaling than rev D - write_reg(MPUREG_ACCEL_CONFIG, 1 << 3); + write_checked_reg(MPUREG_ACCEL_CONFIG, 1 << 3); break; case MPU6000ES_REV_D6: @@ -639,7 +677,7 @@ void MPU6000::reset() // presumably won't have the accel scaling bug default: // Accel scale 8g (4096 LSB/g) - write_reg(MPUREG_ACCEL_CONFIG, 2 << 3); + write_checked_reg(MPUREG_ACCEL_CONFIG, 2 << 3); break; } @@ -684,6 +722,7 @@ MPU6000::probe() case MPU6000_REV_D9: case MPU6000_REV_D10: debug("ID 0x%02x", _product); + _checked_values[0] = _product; return OK; } @@ -734,7 +773,7 @@ MPU6000::_set_dlpf_filter(uint16_t frequency_hz) } else { filter = BITS_DLPF_CFG_2100HZ_NOLPF; } - write_reg(MPUREG_CONFIG, filter); + write_checked_reg(MPUREG_CONFIG, filter); } ssize_t @@ -1094,12 +1133,12 @@ MPU6000::gyro_ioctl(struct file *filp, int cmd, unsigned long arg) } uint8_t -MPU6000::read_reg(unsigned reg) +MPU6000::read_reg(unsigned reg, uint32_t speed) { uint8_t cmd[2] = { (uint8_t)(reg | DIR_READ), 0}; // general register transfer at low clock speed - set_frequency(MPU6000_LOW_BUS_SPEED); + set_frequency(speed); transfer(cmd, cmd, sizeof(cmd)); @@ -1144,6 +1183,17 @@ MPU6000::modify_reg(unsigned reg, uint8_t clearbits, uint8_t setbits) write_reg(reg, val); } +void +MPU6000::write_checked_reg(unsigned reg, uint8_t value) +{ + write_reg(reg, value); + for (uint8_t i=0; i<MPU6000_NUM_CHECKED_REGISTERS; i++) { + if (reg == _checked_registers[i]) { + _checked_values[i] = value; + } + } +} + int MPU6000::set_range(unsigned max_g) { @@ -1216,6 +1266,52 @@ MPU6000::measure_trampoline(void *arg) } void +MPU6000::check_registers(void) +{ + /* + we read the register at full speed, even though it isn't + listed as a high speed register. The low speed requirement + for some registers seems to be a propgation delay + requirement for changing sensor configuration, which should + not apply to reading a single register. It is also a better + test of SPI bus health to read at the same speed as we read + the data registers. + */ + uint8_t v; + if ((v=read_reg(_checked_registers[_checked_next], MPU6000_HIGH_BUS_SPEED)) != + _checked_values[_checked_next]) { + /* + if we get the wrong value then we know the SPI bus + or sensor is very sick. We set _register_wait to 20 + and wait until we have seen 20 good values in a row + before we consider the sensor to be OK again. + */ + perf_count(_bad_registers); + + /* + try to fix the bad register value. We only try to + fix one per loop to prevent a bad sensor hogging the + bus. We skip zero as that is the PRODUCT_ID, which + is not writeable + */ + if (_checked_next != 0) { + write_reg(_checked_registers[_checked_next], _checked_values[_checked_next]); + } +#if 0 + if (_register_wait == 0) { + ::printf("MPU6000: %02x:%02x should be %02x\n", + (unsigned)_checked_registers[_checked_next], + (unsigned)v, + (unsigned)_checked_values[_checked_next]); + } +#endif + _register_wait = 20; + } else { + _checked_next = (_checked_next+1) % MPU6000_NUM_CHECKED_REGISTERS; + } +} + +void MPU6000::measure() { #pragma pack(push, 1) @@ -1254,6 +1350,8 @@ MPU6000::measure() */ mpu_report.cmd = DIR_READ | MPUREG_INT_STATUS; + check_registers(); + // sensor transfer at high clock speed set_frequency(MPU6000_HIGH_BUS_SPEED); @@ -1292,6 +1390,14 @@ MPU6000::measure() } perf_count(_good_transfers); + + if (_register_wait != 0) { + // we are waiting for some good transfers before using + // the sensor again. We still increment + // _good_transfers, but don't return any data yet + _register_wait--; + return; + } /* @@ -1321,7 +1427,12 @@ MPU6000::measure() * Adjust and scale results to m/s^2. */ grb.timestamp = arb.timestamp = hrt_absolute_time(); - grb.error_count = arb.error_count = 0; // not reported + + // report the error count as the sum of the number of bad + // transfers and bad register reads. This allows the higher + // level code to decide if it should use this sensor based on + // whether it has had failures + grb.error_count = arb.error_count = perf_event_count(_bad_transfers) + perf_event_count(_bad_registers); /* * 1) Scale raw value to SI units using scaling from datasheet. @@ -1411,9 +1522,20 @@ MPU6000::print_info() perf_print_counter(_accel_reads); perf_print_counter(_gyro_reads); perf_print_counter(_bad_transfers); + perf_print_counter(_bad_registers); perf_print_counter(_good_transfers); _accel_reports->print_info("accel queue"); _gyro_reports->print_info("gyro queue"); + ::printf("checked_next: %u\n", _checked_next); + for (uint8_t i=0; i<MPU6000_NUM_CHECKED_REGISTERS; i++) { + uint8_t v = read_reg(_checked_registers[i], MPU6000_HIGH_BUS_SPEED); + if (v != _checked_values[i]) { + ::printf("reg %02x:%02x should be %02x\n", + (unsigned)_checked_registers[i], + (unsigned)v, + (unsigned)_checked_values[i]); + } + } } void |