softwareI2C/i2c.c

#include "i2c.h"

// <20><>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I2C
void i2cInit(void){
	/* <20><>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I2C IO */
	GPIO_InitTypeDef GPIO_InitStruct;
	
	// enable gpiob for rcc_ahb1
	I2C_RCC_CLOCK_CMD;
	
	GPIO_InitStruct.GPIO_Mode		= GPIO_Mode_OUT;
	GPIO_InitStruct.GPIO_OType	= GPIO_OType_OD;
	GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
	GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;	
	
	GPIO_InitStruct.GPIO_Pin = I2C_SCL_PIN | I2C_SDA_PIN;
	GPIO_Init(I2C_GROUP,&GPIO_InitStruct);
	
	// <20><>ʼ<EFBFBD><CABC> I2C <20><><EFBFBD><EFBFBD>Ϊ<EFBFBD>ߵ<EFBFBD>ƽ
	GPIO_SetBits(I2C_GROUP, I2C_SCL_PIN);
	GPIO_SetBits(I2C_GROUP, I2C_SDA_PIN);
	
	// tim2 init
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

	TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

	TIM_TimeBaseStructure.TIM_Period = 0xFFFFFFFF;
	TIM_TimeBaseStructure.TIM_Prescaler = 83;
	TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

	TIM_Cmd(TIM2, ENABLE);
	
	// <20><>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD>Ϻ<EFBFBD><CFBA>ȴ<EFBFBD> 1ms <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɾ<EFBFBD><C9BE>
	//i2cDelay_us(1000);
}

/* us <20><><EFBFBD><EFBFBD>ʱ */
void i2cDelay_us(uint32_t us){
	TIM_SetCounter(TIM2, 0);
	// wait counter to target
	while(TIM_GetCounter(TIM2) < us);
}

/* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƺ<EFBFBD><C6BA><EFBFBD> */
// <20><><EFBFBD>ߵ<EFBFBD>ƽ<EFBFBD><C6BD><EFBFBD><EFBFBD>
void i2cCon_SCL(uint8_t BitValue){
	GPIO_WriteBit(I2C_GROUP, I2C_SCL_PIN, (BitAction)(BitValue));
	i2cDelay_us(i2cSpeedDelay);
}
void i2cCon_SDA(uint8_t BitValue){
	GPIO_WriteBit(I2C_GROUP, I2C_SDA_PIN, (BitAction)(BitValue));
	i2cDelay_us(i2cSpeedDelay);
}

// <20><>ȡ SDA <20><><EFBFBD><EFBFBD>
uint8_t i2cReceive_SDA(void){
	uint8_t bitValue = GPIO_ReadInputDataBit(I2C_GROUP, I2C_SDA_PIN);
	i2cDelay_us(i2cSpeedDelay);
	return bitValue;
}

/* <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD>Ԫ */
// <20><>ʼ<EFBFBD>źźͽ<C5BA><CDBD><EFBFBD><EFBFBD>ź<EFBFBD>
void i2cSignal_Start(void){
	i2cCon_SDA(1);
	i2cCon_SCL(1);
	i2cCon_SDA(0);
	i2cCon_SCL(0);
}
void i2cSignal_Stop(void){
	i2cCon_SDA(0);
	i2cCon_SCL(1);
	i2cCon_SDA(1);
}

/* <20><><EFBFBD><EFBFBD><EFBFBD>շ<EFBFBD> */
// <20><><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>ֽ<EFBFBD>
void i2cSend_Byte(uint8_t byte){
	for(int i = 0; i < 8; i++){
		i2cCon_SDA(!!(byte & (0x80 >> i)));
		i2cCon_SCL(1);
		i2cCon_SCL(0);
	}
}
// <20><><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>ֽ<EFBFBD>
uint8_t i2cReceive_Byte(void){
	uint8_t rByte = 0x00;
	i2cCon_SDA(1);
	
	for(int i = 0; i < 8; i++){
		i2cCon_SCL(1);
		
		if(i2cReceive_SDA() == 1){
			rByte |= (0x80 >> i);
		}
		
		i2cCon_SCL(0);
	}
	
	return rByte;
}

/* Ӧ<><D3A6>λ<EFBFBD><CEBB><EFBFBD><EFBFBD> */
void i2cSend_ACK(uint8_t ackBit){
	i2cCon_SDA(ackBit);
	i2cCon_SCL(1);
	i2cCon_SCL(0);
}
uint8_t i2cReceive_ACK(void){
	i2cCon_SDA(1);
	i2cCon_SCL(1);
	uint8_t ackBit = i2cReceive_SDA();
	i2cCon_SCL(0);
	return ackBit;
}