william/lis3dh
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William Clark 2024-01-06 17:25:44 +00:00
parent c484947cdf
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8
README.md
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@ -25,11 +25,11 @@ This project has example interface code for I2C and SPI used on Raspberry Pi 4,
```c
/* initialise the "interface" */
int init(void);
/* read from register `reg`, `size` amount of bytes, and write them to `dst` */
/* read from register `reg', `size' amount of bytes, and write them to `dst' */
int read(uint8_t reg, uint8_t *dst, uint32_t size);
/* write `value` to register `reg` */
/* write `value' to register `reg' */
int write(uint8_t reg, uint8_t value);
/* sleep for `dur_us` microseconds */
/* sleep for `dur_us' microseconds */
int sleep(uint32_t dur_us);
/* deinitalise the "interface" */
int deinit(void);
@ -42,7 +42,7 @@ If `init` and/or `deinit` are set to `NULL`, they will be ignored. Useful on mic
### STM32
```c
#define LIS3DH_I2C_ADDR 0x18
#define LIS3DH_I2C_ADDR 0x18 /* can also be 0x19 */
int i2c_write(uint8_t reg, uint8_t value) {
uint8_t buf[2] = { reg, value };

13
example/README.md
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@ -4,15 +4,22 @@
Basic example of how to use this device
### file: fifo.c
Instead of polling for every single [x y z] set, a FIFO with programmable capacity ("watermark") can be used, and then dumped into memory once full. All FIFO readings use 10-bit resolution regardless of the mode set in `cfg.mode`. The watermark level can be adjusted to a value [1-32] (0 disables FIFO) by modifying the `cfg.fifo.size` property before calling `lis3dh_configure()`.
Instead of polling for every single [x y z] set, a FIFO with programmable capacity ("watermark") can be used, and then dumped into memory once full.
All FIFO readings use 10-bit resolution regardless of the mode set in `cfg.mode`.
The watermark level can be adjusted to a value [1-32] (0 disables FIFO) by modifying the `cfg.fifo.size` property before calling `lis3dh_configure()`.
The LIS3DH can optionally apply a HP filter on the sampling to reduce 'static acceleration' from the data.
Note: it seems that the highest data rate (ODR) possible using FIFO is 200 Hz, faster than that and it does not want to restart after 1 FIFO buffer. To faster faster, such as at the advertised 5 KHz rate, you have to use `lis3dh_read()`.
Note: it seems that the highest data rate (ODR) possible using FIFO is 200 Hz, faster than that and it does not want to restart after 1 FIFO buffer. To sample faster, such as at the advertised 5 KHz rate, you have to use `lis3dh_read()` with `LP` mode.
### file: interrupts.c
This device supports two different interrupt "output pins," `INT1` and `INT2`. The appropriate flag must be set in either `cfg.pin1` or `cfg.pin2` and the interrupt source must be configured to trigger into `INT1` or `INT2`.
This file contains example code that listens and receives an interrupt when the FIFO overrun is reached i.e. it is full. Note: `pin1.wtm` will NOT trigger if the FIFO size is 32 (default). Use `pin1.overrun` if you want an interrupt when the FIFO is full at full size (32.)
This file contains example code that listens and receives an interrupt when the FIFO overrun is reached i.e. it is full.
Note: `pin1.wtm` will NOT trigger if the FIFO size is 32 (default). Use `pin1.overrun` if you want an interrupt when the FIFO is full at full size (32.)
### file: single-click.c