From 1b1aa0edea9214d5e7bab2db634b4fdbf8ad3e95 Mon Sep 17 00:00:00 2001 From: Andrew Tridgell Date: Fri, 6 Dec 2013 20:52:31 +1100 Subject: [PATCH] lsm303d: use DRDY pins to automatically reschedule measurements this prevents double reads of sensor data, and missing samples from the accel --- src/drivers/lsm303d/lsm303d.cpp | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/drivers/lsm303d/lsm303d.cpp b/src/drivers/lsm303d/lsm303d.cpp index 4d7c8f05ac..b13ca9f44c 100644 --- a/src/drivers/lsm303d/lsm303d.cpp +++ b/src/drivers/lsm303d/lsm303d.cpp @@ -287,6 +287,7 @@ private: perf_counter_t _reg7_resets; perf_counter_t _reg1_resets; perf_counter_t _extreme_values; + perf_counter_t _accel_reschedules; math::LowPassFilter2p _accel_filter_x; math::LowPassFilter2p _accel_filter_y; @@ -507,6 +508,7 @@ LSM303D::LSM303D(int bus, const char* path, spi_dev_e device) : _reg1_resets(perf_alloc(PC_COUNT, "lsm303d_reg1_resets")), _reg7_resets(perf_alloc(PC_COUNT, "lsm303d_reg7_resets")), _extreme_values(perf_alloc(PC_COUNT, "lsm303d_extremes")), + _accel_reschedules(perf_alloc(PC_COUNT, "lsm303d_accel_resched")), _accel_filter_x(LSM303D_ACCEL_DEFAULT_RATE, LSM303D_ACCEL_DEFAULT_DRIVER_FILTER_FREQ), _accel_filter_y(LSM303D_ACCEL_DEFAULT_RATE, LSM303D_ACCEL_DEFAULT_DRIVER_FILTER_FREQ), _accel_filter_z(LSM303D_ACCEL_DEFAULT_RATE, LSM303D_ACCEL_DEFAULT_DRIVER_FILTER_FREQ), @@ -635,6 +637,8 @@ LSM303D::reset() _reg7_expected = REG7_CONT_MODE_M; write_reg(ADDR_CTRL_REG7, _reg7_expected); write_reg(ADDR_CTRL_REG5, REG5_RES_HIGH_M); + write_reg(ADDR_CTRL_REG3, 0x04); // DRDY on ACCEL on INT1 + write_reg(ADDR_CTRL_REG4, 0x04); // DRDY on MAG on INT2 accel_set_range(LSM303D_ACCEL_DEFAULT_RANGE_G); accel_set_samplerate(LSM303D_ACCEL_DEFAULT_RATE); @@ -1416,6 +1420,14 @@ LSM303D::mag_measure_trampoline(void *arg) void LSM303D::measure() { + // if the accel doesn't have any data ready then re-schedule + // for 100 microseconds later. This ensures we don't double + // read a value and then miss the next value + if (stm32_gpioread(GPIO_EXTI_ACCEL_DRDY) == 0) { + perf_count(_accel_reschedules); + hrt_call_delay(&_accel_call, 100); + return; + } if (read_reg(ADDR_CTRL_REG1) != _reg1_expected) { perf_count(_reg1_resets); reset();