TCA6424A not responding, times out

	ioBuf[0] = ioBuf[1] = ioBuf[2] = 0;

	// Probe the expander to make sure it's alive and talking

	ioBuf[0] = ReadPorts[0];
	if(I2C_Write(0x22, ioBuf, 1) != TRUE)
	    return FALSE;  

Bool I2C_Write(unsigned int DevAddr, unsigned char *pBuf, int nLength)
{
	Bool retVal = FALSE;
	unsigned int taskKey;

	// For I2C, the sequence is:
	//
	// - Send multi-byte START (START + read first byte)
	// - Send multi-byte READ NEXT for length - 2 (one already sent, see above)
	// - Send multi-byte finish (read last byte + STOP)
	//
	// If we're only sending one byte, it's a single API call and we will
	// special-case tht in the code below.

	taskKey = Task_disable();					// Disable task switching

	// You can't change bus modes without resetting the bus.  So,
	// let's reset the dang thing into RECEIVE mode

	I2C_Init(TRUE);

	SetI2CTarget(DevAddr, TRUE);

	if(nLength == 1)
	{
		// Just send a single byte out and return
		retVal = USCI_B_I2C_masterSendSingleByteWithTimeout(I2C_BASE,  *pBuf, I2C_TIMEOUT);
        USCI_B_I2C_clearInterruptFlag(I2C_BASE, USCI_B_I2C_TRANSMIT_INTERRUPT);
    	Task_restore(taskKey);						// Resrtore task switching
		return retVal;
	}

	// True multi-byte send, process

	if(USCI_B_I2C_masterMultiByteSendStartWithTimeout(I2C_BASE, *pBuf++, I2C_TIMEOUT) == TRUE)
	{
		nLength--;								// First byte went out
		while(nLength-- > 1)
		{
			USCI_B_I2C_masterMultiByteSendNext(I2C_BASE, *pBuf++);
		}
		if(USCI_B_I2C_masterMultiByteSendFinishWithTimeout(I2C_BASE, *pBuf, I2C_TIMEOUT) == TRUE)
			retVal = TRUE;						// Everything succeeded
	}

    USCI_B_I2C_masterMultiByteSendStop(I2C_BASE);

    USCI_B_I2C_clearInterruptFlag(I2C_BASE, USCI_B_I2C_TRANSMIT_INTERRUPT);

	Task_restore(taskKey);						// Resrtore task switching

	return retVal;
}