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/*
* 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 "lis2dh.h"
#include "watch.h"
bool lis2dh_begin() {
if (lis2dh_get_device_id() != LIS2DH_WHO_AM_I_VAL) {
return false;
}
// Enable all axes, start at lowest possible data rate
watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL1, LIS2DH_CTRL1_VAL_XEN |
LIS2DH_CTRL1_VAL_YEN |
LIS2DH_CTRL1_VAL_ZEN |
LIS2DH_CTRL1_VAL_ODR_1HZ);
// Set range to ±2G and enable block data update (output registers not updated until MSB and LSB have been read)
watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL4, LIS2DH_CTRL4_VAL_BDU | LIS2DH_RANGE_2_G);
return true;
}
uint8_t lis2dh_get_device_id() {
return watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_WHO_AM_I);
}
bool lis2dh_have_new_data() {
uint8_t retval = watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_STATUS);
return !!retval; // return true if any bit is set
}
lis2dh_reading lis2dh_get_raw_reading() {
uint8_t buffer[6];
uint8_t reg = LIS2DH_REG_OUT_X_L | 0x80; // set high bit for consecutive reads
lis2dh_reading retval;
watch_i2c_send(LIS2DH_ADDRESS, ®, 1);
watch_i2c_receive(LIS2DH_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;
}
lis2dh_acceleration_measurement lis2dh_get_acceleration_measurement(lis2dh_reading *out_reading) {
lis2dh_reading reading = lis2dh_get_raw_reading();
uint8_t range = lis2dh_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 == LIS2DH_RANGE_2_G) lsb_value = 4;
if (range == LIS2DH_RANGE_4_G) lsb_value = 8;
if (range == LIS2DH_RANGE_8_G) lsb_value = 16;
if (range == LIS2DH_RANGE_16_G) lsb_value = 48;
lis2dh_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 lis2dh_set_range(lis2dh_range_t range) {
uint8_t val = watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL4) & 0xCF;
uint8_t bits = range << 4;
watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL4, val | bits);
}
lis2dh_range_t lis2dh_get_range() {
uint8_t retval = watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL4) & 0x30;
retval >>= 4;
return (lis2dh_range_t)retval;
}
void lis2dh_set_data_rate(lis2dh_data_rate_t dataRate) {
uint8_t val = watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL1) & 0x0F;
uint8_t bits = dataRate << 4;
watch_i2c_write8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL1, val | bits);
}
lis2dh_data_rate_t lis2dh_get_data_rate() {
return watch_i2c_read8(LIS2DH_ADDRESS, LIS2DH_REG_CTRL1) >> 4;
}
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