BOOL I2C_startTransfer(I2C_MODULE I2C_ID, BOOL restart){
I2C_STATUS status;
// Send the Start (or Restart) signal
if(restart){
if(I2CRepeatStart(I2C_ID) != I2C_SUCCESS){
#ifdef DEBUG
printf("Error: Bus collision during transfer Start at Read\n");
#endif
return FALSE;
}
}
else{
// Wait for the bus to be idle, then start the transfer
while( !I2CBusIsIdle(I2C_ID) );
if(I2CStart(I2C_ID) != I2C_SUCCESS){
#ifdef DEBUG
printf("Error: Bus collision during transfer Start at Write\n");
#endif
return FALSE;
}
}
// Wait for the signal to complete
do{
status = I2CGetStatus(I2C_ID);
}
while (!(status & I2C_START) );
return TRUE;
}
/****** I2C Driver implementation *******/
static bool StartTransfer(I2C_MODULE i2c_id, bool restart)
{
I2C_STATUS status;
// Send the Start (or Restart) signal
if (restart)
{
I2CRepeatStart(i2c_id);
}
else
{
// Wait for the bus to be idle, then start the transfer
while (!I2CBusIsIdle(i2c_id));
if (I2CStart(i2c_id) != I2C_SUCCESS)
{
//DBPRINTF("Error: Bus collision during transfer Start\n");
return FALSE;
}
}
// Wait for the signal to complete
do
{
status = I2CGetStatus(i2c_id);
} while (!(status & I2C_START));
return TRUE;
}
/*
Sends a start to begin i2c transaction (with no strings attached)
*/
void sendStart(I2C_MODULE i2c){
while( ! I2CBusIsIdle(i2c));
DelayMs(2); // timing for ADXL345
I2CStart(i2c);
while( ! (I2CGetStatus(i2c) & I2C_START) );
I2CClearStatus(i2c, I2C_START);
}
//==============================================================================
BOOL i2c_Start(UINT8 restart )
{
I2C_STATUS status;
// Send the Start (or Restart) signal
if(restart)
{
//I2CRepeatStart(EEPROM_I2C_BUS);
I2C1CONbits.RSEN = 1;
}
else
{
// Wait for the bus to be idle, then start the transfer
while( !I2CBusIsIdle(EEPROM_I2C_BUS) );
if(I2CStart(EEPROM_I2C_BUS) != I2C_SUCCESS)
{
DBPRINTF("Error: Bus collision during transfer Start\n");
return FALSE;
}
}
// Wait for the signal to complete
do
{
status = I2CGetStatus(EEPROM_I2C_BUS);
} while ( !(status & I2C_START) );
return TRUE;
}
int transfer_start(I2C_MODULE port, I2C_7_BIT_ADDRESS address, UINT8 rw)
{
I2C_STATUS status;
int result = 0;
while(!I2CBusIsIdle(port));
if(I2CStart(port) != I2C_SUCCESS)
return -1;
do {
status = I2CGetStatus(port);
} while(!(status & I2C_START));
/* Send address */
address.rw = rw;
result = transmit_byte(port, address.byte);
if(result < 0)
return result;
if(!I2CByteWasAcknowledged(port))
return -1;
return result;
}
/**
* Invokes an I2C stop condition
*
*/
void I2C_StopTransfer()
{
// Send the Stop signal
I2CStop(I2C1);
// Wait for the signal to complete
while (!(I2CGetStatus(I2C1) & I2C_STOP));
}
static int transfer_stop(I2C_MODULE port)
{
I2C_STATUS status;
I2CStop(port);
do {
status = I2CGetStatus(port);
} while(!(status & I2C_STOP));
}
/**************************************************************************************************
Function:
void I2CShared_StopTransfer(const I2C_MODULE i2c)
Author(s):
mkobit
Summary:
Stops a transaction on the (i2c) module
Description:
Sends a stop signal and waits until the signal is complete
Static function, used by internal library
Preconditions:
I2C module configured
Parameters:
const I2C_MODULE i2c - I2C module to be used for this transaction
Returns:
void
Example:
<code>
I2CShared_StopTransfer(I2C1)
</code>
Conditions at Exit:
I2C bus idle
**************************************************************************************************/
static void I2CShared_StopTransfer(const I2C_MODULE i2c) {
I2C_STATUS status;
// Send the Stop signal
I2CStop(i2c);
// Wait for the signal to complete
do {
status = I2CGetStatus(i2c);
} while (!(status & I2C_STOP));
}
void I2C_stopTransfer(I2C_MODULE I2C_ID){
I2C_STATUS status;
// Send the Stop signal
I2CStop(I2C_ID);
// Wait for the signal to complete
do{
status = I2CGetStatus(I2C_ID);
}
while (!(status & I2C_STOP));
}
void StopTransfer( void )
{
I2C_STATUS status;
// Send the Stop signal
I2CStop(PIC24_I2C_BUS);
// Wait for the signal to complete
do
{
status = I2CGetStatus(PIC24_I2C_BUS);
} while ( !(status & I2C_STOP) );
}
//==============================================================================
void i2c_Stop( void )
{
I2C_STATUS status;
// Send the Stop signal
I2CStop(EEPROM_I2C_BUS);
// Wait for the signal to complete
do
{
status = I2CGetStatus(EEPROM_I2C_BUS);
} while ( !(status & I2C_STOP) );
}
/**************************************************************************************************
Function:
static void I2CShared_DebugStatus(const I2C_MODULE i2c)
Author(s):
mkobit
Summary:
Prints out statuses of the I2C module that is passed in
Description:
Useful for debugging when errors occur to see what the current state of the I2C module is
Static function, used by internal library
Preconditions:
I2C module
UART2 preconfigured as debugging output
Parameters:
const I2C_MODULE i2c - I2C module to print out status messages
Returns:
void
Example:
<code>
I2CShared_DebugStatus(I2C1)
</code>
Conditions at Exit:
None
**************************************************************************************************/
static void I2CShared_DebugStatus(const I2C_MODULE i2c) {
I2C_STATUS status;
status = I2CGetStatus(i2c);
if (I2C_TRANSMITTER_FULL & status) {
//printf("I2CShared_DebugStatus: I2C_TRANSMITTER_FULL, 0x%x\n", I2C_TRANSMITTER_FULL & status);
}
if (I2C_DATA_AVAILABLE & status) {
//printf("I2CShared_DebugStatus:) I2C_DATA_AVAILABLE, 0x%x\n", I2C_DATA_AVAILABLE & status);
}
if (I2C_SLAVE_READ & status) {
//printf("I2CShared_DebugStatus:) I2C_SLAVE_READ, 0x%x\n", I2C_SLAVE_READ & status);
}
if (I2C_START & status) {
//printf("I2CShared_DebugStatus: I2C_START, 0x%x\n", I2C_START & status);
}
if (I2C_STOP & status) {
//printf("I2CShared_DebugStatus: I2C_STOP, 0x%x\n", I2C_STOP & status);
}
if (I2C_SLAVE_DATA & status) {
//printf("I2CShared_DebugStatus: I2C_SLAVE_DATA, 0x%x\n", I2C_SLAVE_DATA & status);
}
if (I2C_RECEIVER_OVERFLOW & status) {
//printf("I2CShared_DebugStatus: I2C_RECEIVER_OVERFLOW, 0x%x\n", I2C_RECEIVER_OVERFLOW & status);
}
if (I2C_TRANSMITTER_OVERFLOW & status) {
//printf("I2CShared_DebugStatus: I2C_TRANSMITTER_OVERFLOW, 0x%x\n", I2C_TRANSMITTER_FULL & status);
}
if (I2C_10BIT_ADDRESS & status) {
//printf("I2CShared_DebugStatus: I2C_10BIT_ADDRESS, 0x%x\n", I2C_10BIT_ADDRESS & status);
}
if (I2C_GENERAL_CALL & status) {
//printf("I2CShared_DebugStatus: I2C_GENERAL_CALL, 0x%x\n", I2C_GENERAL_CALL & status);
}
if (I2C_ARBITRATION_LOSS & status) {
//printf("I2CShared_DebugStatus: I2C_ARBITRATION_LOSS, 0x%x\n", I2C_ARBITRATION_LOSS & status);
}
if (I2C_TRANSMITTER_BUSY & status) {
//printf("I2CShared_DebugStatus: I2C_TRANSMITTER_BUSY, 0x%x\n", I2C_TRANSMITTER_BUSY & status);
}
if (I2C_BYTE_ACKNOWLEDGED & status) {
//printf("I2CShared_DebugStatus: I2C_BYTE_ACKNOWLEDGE, 0x%x\n", I2C_BYTE_ACKNOWLEDGED & status);
}
if (status == 0) {
//printf("I2CShared_DebugStatus: no status\n");
}
}
/**
* Invokes an I2C start condition
*
* @param restart invoke a restart condition if true
*/
void I2C_StartTransfer(bool restart)
{
// Send the Start (or Restart) signal
if (restart) {
I2CRepeatStart(I2C1);
} else {
// Wait for the bus to be idle, then start the transfer
while (!I2CBusIsIdle(I2C1));
if (I2CStart(I2C1) != I2C_SUCCESS) {
//serialPrint("Error: Bus collision during transfer Start\r\n");
while (1);
}
}
// Wait for the signal to complete
while (!(I2CGetStatus(I2C1) & I2C_START));
}
/**************************************************************************************************
Function:
static BOOL I2CShared_StartTransfer(const I2C_MODULE i2c, const BOOL restart)
Author(s):
mkobit
Summary:
Starts or restarts a transaction
Description:
Blocks until transaction has been started, restarts the transaction if (restart) is TRUE
Static function, used by internal library
Preconditions:
I2C module configured
*Transaction started - *only if (restart) is TRUE
Parameters:
const I2C_MODULE i2c - I2C module to be used for this transaction
const BOOL restart - restart transaction when TRUE, just start when FALSE
Returns:
TRUE - If successful
FALSE - If unsuccessful
Example:
<code>
I2CShared_StartTransfer(i2c, FALSE)
</code>
Conditions at Exit:
Bus transaction started
I2C waiting for next action
**************************************************************************************************/
static BOOL I2CShared_StartTransfer(const I2C_MODULE i2c, const BOOL restart) {
I2C_STATUS status;
int fault_count = 0;
// Send the start/restart signal
if(restart) {
I2CRepeatStart(i2c);
}
else {
// Wait for the bus to be idle, then start the transfer
while(!I2CBusIsIdle(i2c)){
if (fault_count++ == TIMEOUT) {
//printf("I2CShared_StartTransfer: Timeout waiting for bus to be idle\n");
return FALSE;
}
}
if(I2CStart(i2c) == I2C_ARBITRATION_LOSS)
{
//printf("I2CShared_StartTransfer: I2CStart experienced I2C_ARBITRATION_LOSS\n");
//I2CShared_DebugStatus(i2c);
return FALSE;
}
}
fault_count = 0;
// Wait for the signal to complete
do {
status = I2CGetStatus(i2c);
if (status & I2C_ARBITRATION_LOSS) {
//printf("I2CShared_StartTransfer: lost arbitration on i2c bus\n");
return FALSE;
}
if (fault_count++ == TIMEOUT) {
//printf("I2CShared_StartTransfer: Timeout waiting for bus to start\n");
return FALSE;
}
} while (!(status & I2C_START));
return TRUE;
}
void MPU6050::StopTransfer( void )
{
I2C_STATUS status;
UINT8 count = 0;
// Send the Stop signal
I2CStop( this->i2cBusId );
// Wait for the signal to complete
do
{
status = I2CGetStatus( this->i2cBusId );
count++;
} while ( !(status & I2C_STOP) && count < 200);
if ( count >= 200 )
{
sprintf( filename, "Error: StopTransfer(). Loop timeout for I2CGetStatus().\n" );
putsUART1( filename );
}
}
void i2c1_interrupt_handler(void)
{
unsigned long woken = FALSE;
int status = I2CGetStatus(I2C1);
if (state == I2C_STATE_START && !(status & I2C_TRANSMITTER_BUSY)) {
} else if (state == I2C_STATE_TRANSMIT && !(status & I2C_TRANSMITTER_FULL)) {
} else if (state == I2C_STATE_REPEATED_START && !(status & I2C_TRANSMITTER_BUSY)) {
} else if (state == I2C_STATE_STOP && !(status & I2C_STOP)) {
} else if (state == I2C_STATE_RECEIVE && !(status & I2C_DATA_AVAILABLE)) {
} else if (state == I2C_STATE_ACKNOWLEDGE && !(status & I2C_TRANSMITTER_BUSY)) {
} else {
return;
}
semaphore_give_from_isr(bus_lock, &woken);
}
BOOL StartTransfer( BOOL restart )
{
I2C_STATUS status;
// Send the Start (or Restart) signal
if(restart)
{
I2CRepeatStart(PIC24_I2C_BUS);
}
else
{
// Wait for the bus to be idle, then start the transfer
while( !I2CBusIsIdle(PIC24_I2C_BUS) );
if(I2CStart(PIC24_I2C_BUS) != I2C_SUCCESS)
{
DBPRINTF("Error: Bus collision during transfer Start\n");
printf("bus coll\n");
//Succ = FALSE;
//goto RECOVER;
}
}
// Wait for the signal to complete
do
{
status = I2CGetStatus(PIC24_I2C_BUS);
//printf("waiting for signal\n");
} while ( !(status & I2C_START) );
RECOVER:
//if(!Succ) return FALSE;
//else return TRUE;
return TRUE;
}
BOOL MPU6050::StartTransfer( BOOL restart )
{
I2C_STATUS status = I2C_START;
//UINT16 count = 0;
//sprintf(filename, "Starting StartTransfer(), status = %d.\n", status);
//putsUART1( filename );
// Send the Start (or Restart) signal
if(restart)
{
I2C_RESULT res = I2C_SUCCESS;
if((res = I2CRepeatStart( this->i2cBusId )) != I2C_SUCCESS)
{
sprintf(filename, "Repeat start, status = %d.\n",res);
putsUART1( filename );
// Do not return, try to connect anyway and fail
}
}
else
{
// Wait for the bus to be idle, then start the transfer
//while( !I2CBusIsIdle(MPU6050_I2C_BUS) );
// Checks if the bus is idle, and starts the transfer if so
if( I2CBusIsIdle( this->i2cBusId ) )
{
if(I2CStart( this->i2cBusId ) != I2C_SUCCESS)
{
//DBPRINTF("Error: Bus collision during transfer Start\n");
sprintf( filename, "Error in I2CStart(). Bus collision on bus %u during transfer Start.\n", (unsigned)this->i2cBusId );
putsUART1( filename );
return FALSE;
}
}
else
{
sprintf( filename, "Error in I2CBusIsIdle(). Bus %u is not idle.\n", (unsigned)this->i2cBusId );
putsUART1( filename );
return FALSE;
}
}
//sprintf( filename, "StartTransfer(). Checking for Start response...\n" );
//putsUART1( filename );
UINT16 max_tries = 64000, count = 0;
// Wait for the signal to complete or until tries are out
do
{
status = I2CGetStatus( this->i2cBusId );
//sprintf( filename, "StartTransfer(). Status is %u \n", status & I2C_START );
//putsUART1( filename );
} while (!(status & I2C_START) && ++count < max_tries);
if( count >= max_tries )
{
sprintf( filename, "Error in StartTransfer(). Timeout!\n" );
putsUART1( filename );
return FALSE;
}
//sprintf( filename, "StartTransfer(). Function successfully completed!\n" );
//putsUART1( filename );
return TRUE;
}
void i2cStart(I2C_MODULE id){
while( !I2CBusIsIdle(id) );
I2CStart(id);
while ( !(I2CGetStatus(id) & I2C_START) );
}void i2cSendByte(I2C_MODULE id, BYTE data){
void i2cRepeatedStart(I2C_MODULE id){
I2CRepeatStart(id);
while ( !(I2CGetStatus(id) & I2C_START) );
}
void i2cStop(I2C_MODULE id){
I2CStop(id);
while ( !(I2CGetStatus(id) & I2C_STOP) );
}
/*
Sends a start inside i2c transaction (with no strings attached)
*/
void repeatStart(I2C_MODULE I2C){
I2CRepeatStart(I2C);
while( ! (I2CGetStatus(I2C) & I2C_START) );
I2CClearStatus(I2C, I2C_START);
}
//************************************************************
// Synchronous READ - I2C API (visible externally) component
//************************************************************
uint I2CSyncRead( uint I2Cx,
byte DevAddr,
byte Register,
byte* Buffer,
uint BufLen )
{
if (!_I2C_Init) return I2CRC_NRDY;
//=========================================================
// Obtain references to proper Control Blocks and registers
//---------------------------------------------------------
_I2C_CB* pCB;
if ( NULL == (pCB = I2CpCB(I2Cx)) ) return I2CRC_NOTA;
//---------------------------------------------------------
I2C_CONBITS* pCON = I2CpCON(pCB);
I2C_STATBITS* pSTAT = I2CpSTAT(pCB);
//=========================================================
// Validate run-time conditions
//---------------------------------------------------------
uint RC;
BYTE CPU_IPL;
uint RetryCount = 0;
//---------------------------------------------------------
// Enter I2C (and related modules) CRITICAL SECTION
//---------------------------------------------------------
Retry:
RC = I2CRC_OK;
//------------------------------------
SET_AND_SAVE_CPU_IPL(CPU_IPL, _I2C_IL);
{
if (I2CRC_OK == (RC=I2CGetStatus(pCB, pCON, pSTAT)))
//---------------------------------------------------------
// Set Flag indicating Synchronous operation is in progress
//---------------------------------------------------------
pCB->_I2C_SBSY = 1; // Should be cleared at exit
}
//---------------------------------------------------------
// Leave I2C CRITICAL SECTION
//---------------------------------------------------------
RESTORE_CPU_IPL(CPU_IPL);
//=========================================================
switch (RC)
{
case I2CRC_OK:
break; // Run-time conditions are OK
//-------------------------------------------
case I2CRC_ABSY:
case I2CRC_SBSY:
case I2CRC_BUSY:
// Situation could be helped by delay/retry
if (RetryCount < I2C_BUSYRetry)
{
TMRDelayTicks(1); // Small delay ~125 usec
RetryCount++;
goto Retry; // Attempt retry
}
else; // Fall through to "default"
//-------------------------------------------
default:
return RC; // Run-time conditions are not met
}
//=========================================================
//---------------------------------------------------------
// Event sequence to accomplish simple READ from the target
// slave device in the MASTER mode:
// 1. Assert a Start condition on SDAx and SCLx.
// 2. Send the I2C device address byte to the slave with a
// read indication ("1" in the LSB of address)
// 3. Wait for and verify an Acknowledge from the slave.
// 4. Assert receiving state (RCEN = 1).
// 5. Receive byte and send ACK to the slave.
// 6. Repeat steps 4 and 5 for every byte in a message,
// except the last - after receiving last byte send NACK.
// 7. Generate a Stop condition on SDAx and SCLx.
//---------------------------------------------------------
// Prepare READ and WRITE forms of device address
byte i2cAddrW = DevAddr & 0xFE; // Set WRITE cond.
byte i2cAddrR = DevAddr | 0x01; // Set READ cond.
//---------------------------------------------------------
RC = I2CRC_OK;
//---------------------------------------------------------
I2CStart(pCB); // Signal START on SDA and SCL pins
//---------------------------------------------------------
// Send Device WRITE address
//---------------------------------------------------------
RC = I2CMasterWriteByte(pCB, i2cAddrW);
if (RC != I2CRC_OK) goto Finally;
//---------------------------------------------------------
// Send Register address (as data))
//---------------------------------------------------------
RC = I2CMasterWriteByte(pCB, Register);
if (RC != I2CRC_OK) goto Finally;
//---------------------------------------------------------
I2CReStart(pCB); // Signal Repeated-START on SDA and SCL pins
//---------------------------------------------------------
// Send Device READ address
//---------------------------------------------------------
RC = I2CMasterWriteByte(pCB, i2cAddrR);
if (RC != I2CRC_OK) goto Finally;
//---------------------------------------------------------
// Receive data
//---------------------------------------------------------
pSTAT->I2COV = 0; // Clear receive OVERFLOW bit, if any
//---------------------------------------------------------
uint BufPos;
uint BufCnt = BufLen;
//---------------------------------------------------------
for (BufPos = 0; BufPos < BufLen; BufPos++)
{
BufCnt--; // Used as a FLAG (BufCnt=0) to indicate last byte
//---------------------------------------------------------
RC = I2CMasterReadByte(pCB, Buffer, BufCnt);
if (RC != I2CRC_OK)
break; // Error...
Buffer++;
}
//---------------------------------------------------------
Finally:
I2CStop(pCB); // Signal STOP on SDA and SCL pins
//---------------------------------------------------------
pCB->_I2C_SBSY = 0; // Clear SYNC flag
return RC; // Return last Error Code...
}
