90 lines
2.5 KiB
Markdown
90 lines
2.5 KiB
Markdown
# LIS3DH
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A C89 driver for the 3-axis accelerometer LIS3DH. Supports both I2C and SPI.
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### Features
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> - FIFO
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> - HP filter
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> - 2G, 4G, 8G and 16G
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> - Low-power mode, normal mode and high-resolution mode
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> - ADC and temperature sensing
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> - Interrupt generation
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> - Free-fall detection
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> - Single-click detection
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> - Double-click detection
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> - 4D/6D orientation detection
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## Examples
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See the `examples/` dir for complete code examples and explanations of LIS3DH terminology
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## Implementation
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This driver requires the user to implement the following interface functions:
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This project has example interface code for I2C and SPI used on Raspberry Pi 4, and for STM32.
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```c
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/* initialise the "interface" */
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int init(void);
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/* read from register `reg', `size' amount of bytes, and write them to `dst' */
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int read(uint8_t reg, uint8_t *dst, uint32_t size);
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/* write `value' to register `reg' */
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int write(uint8_t reg, uint8_t value);
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/* sleep for `dur_us' microseconds */
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int sleep(uint32_t dur_us);
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/* deinitalise the "interface" */
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int deinit(void);
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```
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All above functions return `0` on success, and any non-zero value on error.
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If `init` and/or `deinit` are set to `NULL`, they will be ignored. Useful on microcontrollers.
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---
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## Functions
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```c
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int lis3dh_init(lis3dh_t *lis3dh);
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int lis3dh_deinit(lis3dh_t *lis3dh);
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int lis3dh_configure(lis3dh_t *lis3dh);
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int lis3dh_read(lis3dh_t *lis3dh);
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int lis3dh_read_fifo(lis3dh_t *lis3dh, struct lis3dh_fifo_data *fifo);
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int lis3dh_read_int1(lis3dh_t *lis3dh);
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int lis3dh_read_int2(lis3dh_t *lis3dh);
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int lis3dh_read_click(lis3dh_t *lis3dh);
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int lis3dh_reference(lis3dh_t *lis3dh);
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int lis3dh_reset(lis3dh_t *lis3dh);
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int lis3dh_read_adc(lis3dh_t *lis3dh);
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int lis3dh_read_temp(lis3dh_t *lis3dh);
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int lis3dh_fifo_reset(lis3dh_t *lis3dh);
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```
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All functions return `0` on success, and any non-zero value on error.
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## STM32
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Example i2c and SPI functions that work
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### i2c
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```c
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#define LIS3DH_I2C_ADDR 0x18 /* can also be 0x19 */
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int i2c_write(uint8_t reg, uint8_t value) {
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uint8_t buf[2] = { reg, value };
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HAL_I2C_Master_Transmit(&hi2c2, LIS3DH_I2C_ADDR << 1, buf, 2, HAL_MAX_DELAY);
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return 0;
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}
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int i2c_read(uint8_t reg, uint8_t *dst, uint32_t size) {
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if (size > 1) {
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reg |= 0x80; /* auto-increment bit */
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}
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uint8_t send[2] = { reg, 0x00 };
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HAL_I2C_Master_Transmit(&hi2c2, LIS3DH_I2C_ADDR << 1, send, 2, HAL_MAX_DELAY);
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HAL_I2C_Master_Receive(&hi2c2, LIS3DH_I2C_ADDR << 1, dst, size, HAL_MAX_DELAY);
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return 0;
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}
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```
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### SPI
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```c
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TODO
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```
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