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/**
* 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];
// Simple error trap
static void i2c_tmp75_error_cb(I2CDriver *i2cp, 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, I2CSlaveConfig *i2cscfg){
int16_t temperature = 0;
/* Manually send stop signal to the bus. This is important! */
i2cMasterStop(i2cp);
/* unlock bus */
i2cReleaseBus(&I2CD2);
/* store temperature value */
temperature = (i2cscfg->rxbuf[0] << 8) + i2cscfg->rxbuf[1];
}
// Fill TMP75 config.
static I2CSlaveConfig tmp75 = {
i2c_tmp75_cb,
i2c_tmp75_error_cb,
tmp75_rx_data,
TMP75_RX_DEPTH,
0,
0,
tmp75_tx_data,
TMP75_TX_DEPTH,
0,
0,
0b1001000,
FALSE,
};
/* This is main function. */
void request_temperature(void){
tmp75.txbytes = 0; // set to zero just to be safe
/* tune receiving buffer */
tmp75.rxbufhead = 0;// point to beginig of buffer
tmp75.rxbytes = 2; // we need read 2 bytes
/* get exclusive access to the bus */
i2cAcquireBus(&I2CD2);
/* start receiving process in background and return */
i2cMasterReceive(&I2CD2, &tmp75);
}
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