portextender.c

ADS1241与MSP430F449接口设计

#include "hpa449lib.h"

int WriteExpandedGPIO (int PortExtenderAddress, int Value)
{
	int fOK;
	// Start condition
	I2C_B_Start();
	// address to port extender
	fOK = I2C_B_SendByte(0x70 | (PortExtenderAddress << 1));
	fOK &= I2C_B_SendByte(Value);	// write data to port extender
	I2C_B_Stop();
	return fOK;
}

int ReadExpandedGPIO (int PortExtenderAddress, unsigned char * Value)
{
	int fOK = 1;
	// Start condition
	I2C_B_Start();
	// address to port extender
	if (I2C_B_SendByte(0x71 | (PortExtenderAddress << 1)))
	{
		*Value = I2C_B_ReceiveByte(0);	// write data to port extender
	}
	else
		fOK = 0;
	I2C_B_Stop();
	return fOK;
}