/*********************************************************************
*
* _Write
*
* Function description
* Writes to a device on I2C.
*/
static U8 _Write(U8 Addr, U8 * pData, U16 NumBytesToWrite, U8 PartOfWriteRead) {
U8 r;
U16 i;
r = _I2C_Start(); // Generate Start condition
if(r == I2C_CODE_OK) {
r = _I2C_WriteWithWait(Addr); // Write address (SLA+W)
if (r == I2C_CODE_OK) {
//
// Write data
//
for (i = 0; i < NumBytesToWrite; i++) {
r = _I2C_WriteWithWait(*pData);
if (r != I2C_CODE_OK) {
PartOfWriteRead = 0; // Override to generate stop condition on error
break;
}
pData++;
}
}
}
if (PartOfWriteRead == 0) {
_I2C_Stop(); // Generate Stop condition
}
return r;
}
uint8_t digipot_mcp4451_start(uint8_t sla) { // send slave address and write bit
// Sometimes TX data ACK or NAK status is returned. That mean the start state didn't
// happen which means only the value of the slave address was send. Keep looping until
// the slave address and write bit are actually sent.
do{
_I2C_Stop(I2CDEV_M); // output stop state on I2C bus
_I2C_Start(I2CDEV_M); // output start state on I2C bus
while ((I2C_status != I2C_I2STAT_M_TX_START)
&& (I2C_status != I2C_I2STAT_M_TX_RESTART)
&& (I2C_status != I2C_I2STAT_M_TX_DAT_ACK)
&& (I2C_status != I2C_I2STAT_M_TX_DAT_NACK)); //wait for start to be asserted
LPC_I2C1->I2CONCLR = I2C_I2CONCLR_STAC; // clear start state before tansmitting slave address
LPC_I2C1->I2DAT = (sla <<1) & I2C_I2DAT_BITMASK; // transmit slave address & write bit
LPC_I2C1->I2CONSET = I2C_I2CONSET_AA;
LPC_I2C1->I2CONCLR = I2C_I2CONCLR_SIC;
while ((I2C_status != I2C_I2STAT_M_TX_SLAW_ACK)
&& (I2C_status != I2C_I2STAT_M_TX_SLAW_NACK)
&& (I2C_status != I2C_I2STAT_M_TX_DAT_ACK)
&& (I2C_status != I2C_I2STAT_M_TX_DAT_NACK)); //wait for slaw to finish
}while ( (I2C_status == I2C_I2STAT_M_TX_DAT_ACK) || (I2C_status == I2C_I2STAT_M_TX_DAT_NACK));
return 1;
}
/*********************************************************************
*
* I2C_PCA9532_WriteRead()
*/
unsigned char I2CPCA9532_WriteRead(unsigned char * pData, unsigned short NumBytesToWrite, unsigned char * pBuf, unsigned short NumBytesToRead) {
unsigned char r = 0;
unsigned char Status = 0;
unsigned short i = 0;
r = _I2C_Start(); // Generate Start condition
if(r != I2C_CODE_OK) {
goto STOPWRITE;
}
r = _I2C_WriteWithWait(0xC0); // Write PCA9532 address
if (r != I2C_CODE_OK) {
goto STOPWRITE;
}
//
// Write data
//
for (i = 0; i < NumBytesToWrite; i++) {
r = _I2C_WriteWithWait(*pData);
if (r != I2C_CODE_OK) {
goto STOPWRITE;
}
pData++;
}
STOPWRITE:
if (NumBytesToRead > 0) {
r = _I2C_RepeatStart(); // Generate Start condition
//
// Transmit device address
//
if (r == I2C_CODE_OK) {
r = _I2C_PutChar(0xc0 + 0x01); // Write SLA+R
while(r == I2C_CODE_BUSY) {
r = _I2C_PutChar(0xc0 + 0x01);
}
}
//
// Wait until SLA+R transmitted
//
while (1) {
Status = _I2C_CheckStatus();
if (Status == 0x40) { // Data transmitted and ACK received
break;
} else if (Status != 0xF8) { // Error
r = I2C_CODE_ERROR;
break;
}
}
if (r == I2C_CODE_OK) {
//
// Wait until address transmitted and receive data
//
for (i = 1; i <= NumBytesToRead; i++) {
//
// Wait until data transmitted
//
while (1) {
Status = _I2C_CheckStatus();
if ((Status == 0x40) || (Status == 0x48) || (Status == 0x50 )) { // Data received
//
// Set generate NACK
//
if (i == NumBytesToRead) {
r = _I2C_GetChar(I2C_MODE_ACK1, pBuf);
} else {
r = _I2C_GetChar(I2C_MODE_ACK0, pBuf);
}
r = _I2C_GetChar(I2C_MODE_READ, pBuf); // Read data
while (r == I2C_CODE_EMPTY) {
r = _I2C_GetChar(I2C_MODE_READ, pBuf);
}
pBuf++;
break;
} else if (Status != 0xF8) { // Error
i = NumBytesToRead;
r = I2C_CODE_ERROR;
break;
}
}
}
}
}
_I2C_Stop(); // Generate Stop condition
return r;
}
/*********************************************************************
*
* _Read
*
* Function description
* Reads from a device on I2C.
*/
static U8 _Read(U8 Addr, U8 * pData, U16 NumBytesToRead, U8 PartOfWriteRead) {
U16 i;
U8 Status;
U8 r;
//
// Generate start condition
//
if (PartOfWriteRead) {
r = _I2C_RepeatStart(); // Generate Start condition
} else {
r = _I2C_Start(); // Generate Start condition
}
//
// Transmit device address
//
if (r == I2C_CODE_OK) {
r = _I2C_PutChar(Addr + 0x01); // Write address (SLA+R)
while (r == I2C_CODE_BUSY) {
r = _I2C_PutChar(Addr + 0x01);
}
}
//
// Wait until SLA+R transmitted
//
while (1) {
Status = _I2C_CheckStatus();
if (Status == 0x40) { // Data transmitted and ACK received
break;
} else if (Status != 0xF8) { // Error
r = I2C_CODE_ERROR;
break;
}
}
if (r == I2C_CODE_OK) {
//
// Wait until address transmitted and receive data
//
for (i = 1; i <= NumBytesToRead; i++) {
//
// Wait until data transmitted
//
while (1) {
Status = _I2C_CheckStatus();
if ((Status == 0x40) || (Status == 0x48) || (Status == 0x50)) { // Data received
//
// Set generate NACK
//
if (i == NumBytesToRead) {
r = _I2C_GetChar(I2C_MODE_ACK1, pData);
} else {
r = _I2C_GetChar(I2C_MODE_ACK0, pData);
}
r = _I2C_GetChar(I2C_MODE_READ, pData); // Read data
while (r == I2C_CODE_EMPTY) {
r = _I2C_GetChar(I2C_MODE_READ, pData);
}
pData++;
break;
} else if (Status != 0xF8) { // Error
i = NumBytesToRead;
r = I2C_CODE_ERROR;
break;
}
}
}
}
_I2C_Stop(); // Generate Stop condition
return r;
}