tinySA/testhal/STM32/I2C/tmp75.c

57 lines
1.3 KiB
C

/**
* TMP75 is most simple I2C device in our case. It is already useful with
* default settings after powerup.
* You only must read 2 sequential bytes from it.
*/
#include <stdlib.h>
#include "ch.h"
#include "hal.h"
#include "tmp75.h"
/* input buffer */
static i2cblock_t tmp75_rx_data[TMP75_RX_DEPTH];
static i2cblock_t tmp75_tx_data[TMP75_TX_DEPTH];
/* temperature value */
static int16_t temperature = 0;
/* Simple error trap */
static void i2c_tmp75_error_cb(I2CDriver *i2cp, const I2CSlaveConfig *i2cscfg){
(void)i2cscfg;
int status = 0;
status = i2cp->id_i2c->SR1;
while(TRUE);
}
/* This callback raise up when transfer finished */
static void i2c_tmp75_cb(I2CDriver *i2cp, const I2CSlaveConfig *i2cscfg){
(void)*i2cp;
/* store temperature value */
temperature = (i2cscfg->rxbuf[0] << 8) + i2cscfg->rxbuf[1];
}
/* Fill TMP75 config. */
static const I2CSlaveConfig tmp75 = {
i2c_tmp75_cb,
i2c_tmp75_error_cb,
tmp75_rx_data,
tmp75_tx_data,
};
#define tmp75_addr 0b1001000
/* This is main function. */
void request_temperature(void){
#define TXBYTES 0 /* set to zero because we need only reading */
#define RXBYTES 2 /* we need to read 2 bytes */
i2cAcquireBus(&I2CD2);
i2cMasterReceive(&I2CD2, &tmp75, tmp75_addr, RXBYTES);
i2cReleaseBus(&I2CD2);
}