Andy Pomfret
Driver for the LSM303D digital compass. Permits access to all LSM303D registers by name, including multi-byte register sets, and has convenience methods for floating-point accelerometer and magnetometer reads scaled according to the device settings. Written from scratch for Mbed 6.0
Dependents: UoY-32C-lab8-exercise UoY-32C-lab5-lsm303d
Driver for the LSM303D digital compass
Permits access to all LSM303D registers by name, including multi-byte register sets. Convenience methods are included for sensor reads, including floating-point accelerometer and magnetometer reads scaled according to the device settings, and for the more common settings (data rates and scales).
I2C connection only. Written from scratch for Mbed 6.0.
The interface is subject to minor changes with each version. Deprecation warnings will be issued where possible.
Defaults
The class constructor checks that an LSM303D is present on the I2C bus, then enables all sensors. The accelerometer and magnetometer update rates are both set to 50Hz, and the scales are left at their device defaults of +-2g for the accelerometer and +-4gauss for the magnetometer.
Basic usage
Some usage examples
#include "lsm303d.h" LSM303D lsm303d(D14, D15); // SDA and SCL pins for I2C lsm303d.setAccelScale(LSM303D::AccelScale::scale_4g); // set +-4g range lsm303d.INT1_enable_DRDY_A(); // set DRDY_A bit in CTRL3 register (enable INT1 on accel data ready) short rawX = lsm303d.getAccelX(); // returns 16-bit signed result, unscaled float x, y, z; lsm303d.getAccelInto(x, y, z); // overwrites parameters, values in g float mX = lsm303d.getMagX(); // returns value in gauss
Diff: LSM303D.cpp
- Revision:
- 11:0bb2931123d0
- Parent:
- 10:392fa35ca17c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/LSM303D.cpp Wed Feb 17 13:13:13 2021 +0000
@@ -0,0 +1,156 @@
+#include "LSM303D.h"
+
+static unsigned char const accel_lookup[] = {2, 4, 6, 8, 16};
+static unsigned char const mag_lookup[] = {2, 4, 8, 12};
+
+LSM303D::LSM303D(PinName sda, PinName scl, unsigned char i2c_addr) :
+ i2c_(sda, scl), addr_8bit_(i2c_addr << 1),
+ TEMP_OUT (*this, 0x05),
+ STATUS_M (*this, 0x07),
+ OUT_X_M (*this, 0x08),
+ OUT_Y_M (*this, 0x0A),
+ OUT_Z_M (*this, 0x0C),
+ OUT_M (*this, 0x08),
+ WHO_AM_I (*this, 0x0F),
+ INT_CTRL_M (*this, 0x12),
+ INT_SRC_M (*this, 0x13),
+ INT_THS_M (*this, 0x14),
+ OFFSET_X_M (*this, 0x16),
+ OFFSET_Y_M (*this, 0x18),
+ OFFSET_Z_M (*this, 0x1A),
+ OFFSET_M (*this, 0x16),
+ REFERENCE_X (*this, 0x1C),
+ REFERENCE_Y (*this, 0x1D),
+ REFERENCE_Z (*this, 0x1E),
+ REFERENCE (*this, 0x1C),
+ CTRL0 (*this, 0x1F),
+ CTRL1 (*this, 0x20),
+ CTRL2 (*this, 0x21),
+ CTRL3 (*this, 0x22),
+ CTRL4 (*this, 0x23),
+ CTRL5 (*this, 0x24),
+ CTRL6 (*this, 0x25),
+ CTRL7 (*this, 0x26),
+ STATUS_A (*this, 0x27),
+ OUT_X_A (*this, 0x28),
+ OUT_Y_A (*this, 0x2A),
+ OUT_Z_A (*this, 0x2C),
+ OUT_A (*this, 0x28),
+ FIFO_CTRL (*this, 0x2E),
+ FIFO_SRC (*this, 0x2F),
+ IG_CFG1 (*this, 0x30),
+ IG_SRC1 (*this, 0x31),
+ IG_THS1 (*this, 0x32),
+ IG_DUR1 (*this, 0x33),
+ IG_CFG2 (*this, 0x34),
+ IG_SRC2 (*this, 0x35),
+ IG_THS2 (*this, 0x36),
+ IG_DUR2 (*this, 0x37),
+ CLICK_CFG (*this, 0x38),
+ CLICK_SRC (*this, 0x39),
+ CLICK_THS (*this, 0x3A),
+ TIME_LIMIT (*this, 0x3B),
+ TIME_LATENCY(*this, 0x3C),
+ TIME_WINDOW (*this, 0x3D),
+ Act_THS (*this, 0x3E),
+ Act_DUR (*this, 0x3F),
+
+ accel_enableX (CTRL1, 0x01),
+ accel_enableY (CTRL1, 0x02),
+ accel_enableZ (CTRL1, 0x04),
+ accel_enableAll (CTRL1, 0x07),
+
+ INT1_enable_BOOT (CTRL3, 0x80),
+ INT1_enable_CLICK (CTRL3, 0x40),
+ INT1_enable_IG1 (CTRL3, 0x20),
+ INT1_enable_IG2 (CTRL3, 0x10),
+ INT1_enable_IGM (CTRL3, 0x08),
+ INT1_enable_DRDY_A (CTRL3, 0x04),
+ INT1_enable_DRDY_M (CTRL3, 0x02),
+ INT1_enable_EMPTY (CTRL3, 0x01),
+
+ temp_enable (CTRL5, 0x80),
+ LIR1_enable (CTRL5, 0x01)
+
+ {
+ // Check device responds correctly
+ MBED_ASSERT(WHO_AM_I == 0x49);
+
+ // Grab current accelerometer and magnetometer scales from registers
+ accel_scale_ = accel_lookup[(CTRL2 & 0x3E) >> 3];
+ mag_scale_ = mag_lookup[(CTRL6 & 0x60) >> 5];
+
+ // Useful default config
+ accel_enableAll();
+ setAccelRate(AccelRate::rate_50Hz);
+ temp_enable();
+ setMagRate(MagRate::rate_50Hz);
+ setMagMode(MagMode::continuous);
+}
+
+void LSM303D::getRawAccelInto(short &x, short &y, short &z) {
+ i16_3 xyz = OUT_A;
+ x = xyz.x;
+ y = xyz.y;
+ z = xyz.z;
+}
+
+void LSM303D::getAccelInto(float &x, float &y, float &z) {
+ i16_3 xyz = OUT_A;
+ float scale = accel_scale_ / 32768.0;
+ x = xyz.x * scale;
+ y = xyz.y * scale;
+ z = xyz.z * scale;
+}
+
+void LSM303D::getRawMagInto(short &x, short &y, short &z) {
+ i16_3 xyz = OUT_M;
+ x = xyz.x;
+ y = xyz.y;
+ z = xyz.z;
+}
+
+void LSM303D::getMagInto(float &x, float &y, float &z) {
+ i16_3 xyz = OUT_M;
+ float scale = mag_scale_ / 32768.0;
+ x = xyz.x * scale;
+ y = xyz.y * scale;
+ z = xyz.z * scale;
+}
+
+void LSM303D::setAccelRate(AccelRate const &rate) {
+ u8 set = static_cast<u8>(rate);
+ CTRL1 = (CTRL1 & ~0xF0) | set;
+}
+
+void LSM303D::setAccelFilterFreq(AccelFilter const &freq) {
+ u8 set = static_cast<u8>(freq);
+ CTRL2 = (CTRL2 & ~0xC0) | set;
+}
+
+void LSM303D::setAccelScale(AccelScale const &scale) {
+ u8 set = static_cast<u8>(scale);
+ CTRL2 = (CTRL2 & ~0x38) | set;
+ accel_scale_ = accel_lookup[set >> 3];
+}
+
+void LSM303D::setMagRes(MagRes const &res) {
+ u8 set = static_cast<u8>(res);
+ CTRL5 = (CTRL5 & ~0x60) | set;
+}
+
+void LSM303D::setMagRate(MagRate const &rate) {
+ u8 set = static_cast<u8>(rate);
+ CTRL5 = (CTRL5 & ~0x1C) | set;
+}
+
+void LSM303D::setMagScale(MagScale const &scale) {
+ u8 set = static_cast<u8>(scale);
+ CTRL6 = (CTRL6 & ~0x60) | set;
+ mag_scale_ = mag_lookup[set >> 5];
+}
+
+void LSM303D::setMagMode(MagMode const &mode) {
+ u8 set = static_cast<u8>(mode);
+ CTRL7 = (CTRL7 & ~0x03) | set;
+}