1 files changed, 139 insertions, 0 deletions
diff --git a/watch-library/shared/driver/lis2dw.c b/watch-library/shared/driver/lis2dw.c
new file mode 100644
index 00000000..6e1ac56d
--- /dev/null
+++ b/watch-library/shared/driver/lis2dw.c
@@ -0,0 +1,139 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2021 Joey Castillo
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "lis2dw.h"
+#include "watch.h"
+
+bool lis2dw_begin(void) {
+    if (lis2dw_get_device_id() != LIS2DW_WHO_AM_I_VAL) {
+        return false;
+    }
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL2, LIS2DW_CTRL2_VAL_BOOT);
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL2, LIS2DW_CTRL2_VAL_SOFT_RESET);
+    // Start at lowest possible data rate and lowest possible power mode
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL1, LIS2DW_CTRL1_VAL_ODR_LOWEST | LIS2DW_CTRL1_VAL_MODE_LOW_POWER | LIS2DW_CTRL1_VAL_LPMODE_1);
+    // Enable block data update (output registers not updated until MSB and LSB have been read) and address autoincrement
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL2, LIS2DW_CTRL2_VAL_BDU | LIS2DW_CTRL2_VAL_IF_ADD_INC);
+    // Set range to ±2G
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL6, LIS2DW_CTRL6_VAL_RANGE_2G);
+
+    return true;
+}
+
+uint8_t lis2dw_get_device_id(void) {
+    return watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_WHO_AM_I);
+}
+
+bool lis2dw_have_new_data(void) {
+    uint8_t retval = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_STATUS);
+    return retval & LIS2DW_STATUS_VAL_DRDY;
+}
+
+lis2dw_reading lis2dw_get_raw_reading(void) {
+    uint8_t buffer[6];
+    uint8_t reg = LIS2DW_REG_OUT_X_L | 0x80; // set high bit for consecutive reads
+    lis2dw_reading retval;
+
+    watch_i2c_send(LIS2DW_ADDRESS, &reg, 1);
+    watch_i2c_receive(LIS2DW_ADDRESS, (uint8_t *)&buffer, 6);
+
+    retval.x = buffer[0];
+    retval.x |= ((uint16_t)buffer[1]) << 8;
+    retval.y = buffer[2];
+    retval.y |= ((uint16_t)buffer[3]) << 8;
+    retval.z = buffer[4];
+    retval.z |= ((uint16_t)buffer[5]) << 8;
+
+    return retval;
+}
+
+ lis2dw_acceleration_measurement lis2dw_get_acceleration_measurement(lis2dw_reading *out_reading) {
+    lis2dw_reading reading = lis2dw_get_raw_reading();
+    uint8_t range = lis2dw_get_range();
+    if (out_reading != NULL) *out_reading = reading;
+
+    // this bit is cribbed from Adafruit's LIS3DH driver; from their notes, the magic number below
+    // converts from 16-bit lsb to 10-bit and divides by 1k to convert from milli-gs.
+    // final value is raw_lsb => 10-bit lsb -> milli-gs -> gs
+    uint8_t lsb_value = 1;
+    if (range == LIS2DW_RANGE_2_G) lsb_value = 4;
+    if (range == LIS2DW_RANGE_4_G) lsb_value = 8;
+    if (range == LIS2DW_RANGE_8_G) lsb_value = 16;
+    if (range == LIS2DW_RANGE_16_G) lsb_value = 48;
+
+    lis2dw_acceleration_measurement retval;
+
+    retval.x = lsb_value * ((float)reading.x / 64000.0);
+    retval.y = lsb_value * ((float)reading.y / 64000.0);
+    retval.z = lsb_value * ((float)reading.z / 64000.0);
+
+    return retval;
+}
+
+void lis2dw_set_range(lis2dw_range_t range) {
+    uint8_t val = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL6) & ~(LIS2DW_RANGE_16_G << 4);
+    uint8_t bits = range << 4;
+
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL6, val | bits);
+}
+
+lis2dw_range_t lis2dw_get_range(void) {
+    uint8_t retval = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL6) & (LIS2DW_RANGE_16_G << 4);
+    retval >>= 4;
+    return (lis2dw_range_t)retval;
+}
+
+
+void lis2dw_set_data_rate(lis2dw_data_rate_t dataRate) {
+    uint8_t val = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL1) & ~(0b1111 << 4);
+    uint8_t bits = dataRate << 4;
+
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL1, val | bits);
+}
+
+lis2dw_data_rate_t lis2dw_get_data_rate(void) {
+    return watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL1) >> 4;
+}
+
+void lis2dw_set_low_power_mode(lis2dw_low_power_mode_t mode) {
+    uint8_t val = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL1) & ~(0b11);
+    uint8_t bits = mode & 0b11;
+
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL1, val | bits);
+}
+
+lis2dw_low_power_mode_t lis2dw_get_low_power_mode(void) {
+    return watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL1) & 0b11;
+}
+
+void lis2dw_set_low_noise_mode(bool on) {
+    uint8_t val = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL1) & ~(LIS2DW_CTRL6_VAL_LOW_NOISE);
+    uint8_t bits = on ? LIS2DW_CTRL6_VAL_LOW_NOISE : 0;
+
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL1, val | bits);
+}
+
+bool lis2dw_get_low_noise_mode(void) {
+    return (watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_CTRL1) & LIS2DW_CTRL6_VAL_LOW_NOISE) != 0;
+}