nodemcu-firmware/app/modules/adxl345.c

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/*
* Driver for Analog Devices ADXL345 accelerometer.
*
* Code based on BMP085 driver.
*/
#include "module.h"
#include "lauxlib.h"
#include "platform.h"
#include "c_stdlib.h"
#include "c_string.h"
static const uint32_t adxl345_i2c_id = 0;
static const uint8_t adxl345_i2c_addr = 0x53;
static uint8_t ICACHE_FLASH_ATTR r8u(uint32_t id, uint8_t reg) {
uint8_t ret;
platform_i2c_send_start(id);
platform_i2c_send_address(id, adxl345_i2c_addr, PLATFORM_I2C_DIRECTION_TRANSMITTER);
platform_i2c_send_byte(id, reg);
platform_i2c_send_stop(id);
platform_i2c_send_start(id);
platform_i2c_send_address(id, adxl345_i2c_addr, PLATFORM_I2C_DIRECTION_RECEIVER);
ret = platform_i2c_recv_byte(id, 0);
platform_i2c_send_stop(id);
return ret;
}
static int ICACHE_FLASH_ATTR adxl345_init(lua_State* L) {
uint32_t sda;
uint32_t scl;
uint8_t devid;
sda = luaL_checkinteger(L, 1);
scl = luaL_checkinteger(L, 2);
luaL_argcheck(L, sda > 0 && scl > 0, 1, "no i2c for D0");
platform_i2c_setup(adxl345_i2c_id, sda, scl, PLATFORM_I2C_SPEED_SLOW);
devid = r8u(adxl345_i2c_id, 0x00);
if (devid != 229) {
return luaL_error(L, "device not found");
}
// Enable sensor
platform_i2c_send_start(adxl345_i2c_id);
platform_i2c_send_address(adxl345_i2c_id, adxl345_i2c_addr, PLATFORM_I2C_DIRECTION_TRANSMITTER);
platform_i2c_send_byte(adxl345_i2c_id, 0x2D);
platform_i2c_send_byte(adxl345_i2c_id, 0x08);
platform_i2c_send_stop(adxl345_i2c_id);
return 0;
}
static int ICACHE_FLASH_ATTR adxl345_read(lua_State* L) {
uint8_t data[6];
int x,y,z;
int i;
platform_i2c_send_start(adxl345_i2c_id);
platform_i2c_send_address(adxl345_i2c_id, adxl345_i2c_addr, PLATFORM_I2C_DIRECTION_TRANSMITTER);
platform_i2c_send_byte(adxl345_i2c_id, 0x32);
platform_i2c_send_start(adxl345_i2c_id);
platform_i2c_send_address(adxl345_i2c_id, adxl345_i2c_addr, PLATFORM_I2C_DIRECTION_RECEIVER);
for (i=0; i<5; i++) {
data[i] = platform_i2c_recv_byte(adxl345_i2c_id, 1);
}
data[5] = platform_i2c_recv_byte(adxl345_i2c_id, 0);
platform_i2c_send_stop(adxl345_i2c_id);
x = (int16_t) ((data[1] << 8) | data[0]);
y = (int16_t) ((data[3] << 8) | data[2]);
z = (int16_t) ((data[5] << 8) | data[4]);
lua_pushinteger(L, x);
lua_pushinteger(L, y);
lua_pushinteger(L, z);
return 3;
}
static const LUA_REG_TYPE adxl345_map[] = {
{ LSTRKEY( "read" ), LFUNCVAL( adxl345_read )},
{ LSTRKEY( "init" ), LFUNCVAL( adxl345_init )},
{ LNILKEY, LNILVAL}
};
NODEMCU_MODULE(ADXL345, "adxl345", adxl345_map, NULL);