/**************************************************************************************************
* @fn HalI2CWrite
*
* @brief Write to the I2C bus as a Master.
*
* input parameters
*
* @param len - Number of bytes to write.
* @param pBuf - Pointer to the data buffer to write.
*
* output parameters
*
* None.
*
* @return The number of bytes successfully written.
*/
uint8 HalI2CWrite(uint8 len, uint8 *pBuf)
{
if (i2cMstStrt(0) != mstAddrAckW)
{
len = 0;
}
for (uint8 cnt = 0; cnt < len; cnt++)
{
I2C_WRITE(*pBuf++);
if (I2CSTAT != mstDataAckW)
{
if (I2CSTAT == mstDataNackW)
{
len = cnt + 1;
}
else
{
len = cnt;
}
break;
}
}
I2C_STOP();
return len;
}
uint8 HalI2CWriteSingle(uint8 addr, uint8 data)
{
uint8 ret = 0;
if (i2cMstStrt(0) != mstAddrAckW)
{
I2C_STOP();
return ret;
}
I2C_WRITE(addr);
if (I2CSTAT != mstDataAckW) {
I2C_STOP();
return ret;
}
I2C_WRITE(data);
if (I2CSTAT == mstDataAckW) {
ret = 1;
}
I2C_STOP();
return ret;
}
uint8 HalI2CReadSingle(uint8 addr)
{
uint8 ret = 0xFF;
if (i2cMstStrt(0) != mstAddrAckW) {
I2C_STOP();
return ret;
}
I2C_WRITE(addr);
if (I2CSTAT != mstDataAckW) {
I2C_STOP();
return ret;
}
if (i2cMstRepeatedStrt(I2C_MST_RD_BIT) != mstAddrAckR) {
I2C_STOP();
return ret;
}
I2C_SET_NACK();
// read a byte from the I2C interface
I2C_READ(ret);
if (I2CSTAT != mstDataNackR) {
ret = 0xFF;
}
I2C_STOP();
return ret;
}
/**************************************************************************************************
* @fn HalI2CRead
*
* @brief Read from the I2C bus as a Master.
*
* input parameters
*
* @param len - Number of bytes to read.
* @param pBuf - Pointer to the data buffer to put read bytes.
*
* output parameters
*
* None.
*
* @return The number of bytes successfully read.
*/
uint8 HalI2CRead(uint8 len, uint8 *pBuf)
{
uint8 cnt = 0;
if (i2cMstStrt(I2C_MST_RD_BIT) != mstAddrAckR)
{
len = 0;
}
// All bytes are ACK'd except for the last one which is NACK'd. If only
// 1 byte is being read, a single NACK will be sent. Thus, we only want
// to enable ACK if more than 1 byte is going to be read.
if (len > 1)
{
I2C_SET_ACK();
}
while (len > 0)
{
// slave devices require NACK to be sent after reading last byte
if (len == 1)
{
I2C_SET_NACK();
}
// read a byte from the I2C interface
I2C_READ(*pBuf++);
cnt++;
len--;
if (I2CSTAT != mstDataAckR)
{
if (I2CSTAT != mstDataNackR)
{
// something went wrong, so don't count last byte
cnt--;
}
break;
}
}
I2C_STOP();
return cnt;
}
