GPIO模拟IIC，读写AT24C04的代码

以下是GPIO模拟IIC，读写AT24C04的代码：

#include <stdio.h>
#include <wiringPi.h>

#define SDA_PIN 0
#define SCL_PIN 1

void iic_start(void)
{
    pinMode(SDA_PIN, OUTPUT);
    pinMode(SCL_PIN, OUTPUT);
    digitalWrite(SDA_PIN, HIGH);
    digitalWrite(SCL_PIN, HIGH);
    delayMicroseconds(5);
    digitalWrite(SDA_PIN, LOW);
    delayMicroseconds(5);
    digitalWrite(SCL_PIN, LOW);
    delayMicroseconds(5);
}

void iic_stop(void)
{
    pinMode(SDA_PIN, OUTPUT);
    pinMode(SCL_PIN, OUTPUT);
    digitalWrite(SDA_PIN, LOW);
    digitalWrite(SCL_PIN, HIGH);
    delayMicroseconds(5);
    digitalWrite(SDA_PIN, HIGH);
    delayMicroseconds(5);
}

void iic_send_byte(unsigned char data)
{
    int i;
    pinMode(SDA_PIN, OUTPUT);
    pinMode(SCL_PIN, OUTPUT);
    for (i = 0; i < 8; i++) {
        if (data & 0x80) {
            digitalWrite(SDA_PIN, HIGH);
        } else {
            digitalWrite(SDA_PIN, LOW);
        }
        data <<= 1;
        digitalWrite(SCL_PIN, HIGH);
        delayMicroseconds(5);
        digitalWrite(SCL_PIN, LOW);
        delayMicroseconds(5);
    }
}

unsigned char iic_recv_byte(void)
{
    int i;
    unsigned char data = 0;
    pinMode(SDA_PIN, INPUT);
    pinMode(SCL_PIN, OUTPUT);
    for (i = 0; i < 8; i++) {
        data <<= 1;
        digitalWrite(SCL_PIN, HIGH);
        delayMicroseconds(5);
        if (digitalRead(SDA_PIN)) {
            data |= 0x01;
        }
        digitalWrite(SCL_PIN, LOW);
        delayMicroseconds(5);
    }
    return data;
}

void iic_write(unsigned char addr, unsigned char data)
{
    iic_start();
    iic_send_byte(0xa0);
    iic_send_byte(addr);
    iic_send_byte(data);
    iic_stop();
}

unsigned char iic_read(unsigned char addr)
{
    unsigned char data;
    iic_start();
    iic_send_byte(0xa0);
    iic_send_byte(addr);
    iic_start();
    iic_send_byte(0xa1);
    data = iic_recv_byte();
    iic_stop();
    return data;
}

int main(void)
{
    wiringPiSetup();
    iic_write(0x00, 0x55);
    printf("Read data: 0x%02x\n", iic_read(0x00));
    return 0;
}

注意：这个代码仅供参考，具体实现可能需要根据硬件平台和具体情况进行调整。