软件i2c读写数据代码

以下是使用软件模拟I2C总线进行读写数据的示例代码，假设要读写的设备地址为0x50，要读取的寄存器地址为0x10，要写入的数据为0xAB：

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

#define SDA_PIN 0   // SDA引脚
#define SCL_PIN 1   // SCL引脚
#define I2C_ADDR 0x50   // 设备地址

// I2C总线初始化
void i2c_init() {
    pinMode(SDA_PIN, OUTPUT);
    pinMode(SCL_PIN, OUTPUT);
    digitalWrite(SDA_PIN, HIGH);
    digitalWrite(SCL_PIN, HIGH);
}

// I2C总线起始信号
void i2c_start() {
    digitalWrite(SDA_PIN, HIGH);
    digitalWrite(SCL_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(SDA_PIN, LOW);
    delayMicroseconds(10);
    digitalWrite(SCL_PIN, LOW);
    delayMicroseconds(10);
}

// I2C总线停止信号
void i2c_stop() {
    digitalWrite(SDA_PIN, LOW);
    digitalWrite(SCL_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(SDA_PIN, HIGH);
    delayMicroseconds(10);
}

// I2C总线写入一个字节数据并等待ACK信号
int i2c_write_byte(unsigned char data) {
    int i, ack;

    for (i = 0; i < 8; i++) {
        digitalWrite(SDA_PIN, (data & 0x80) ? HIGH : LOW);
        data <<= 1;
        digitalWrite(SCL_PIN, HIGH);
        delayMicroseconds(10);
        digitalWrite(SCL_PIN, LOW);
    }

    // 等待ACK信号
    pinMode(SDA_PIN, INPUT);
    digitalWrite(SCL_PIN, HIGH);
    delayMicroseconds(10);
    ack = digitalRead(SDA_PIN);
    digitalWrite(SCL_PIN, LOW);
    pinMode(SDA_PIN, OUTPUT);

    return (ack == 0);
}

// I2C总线读取一个字节数据并发送ACK信号
unsigned char i2c_read_byte(int ack) {
    int i;
    unsigned char data = 0;

    pinMode(SDA_PIN, INPUT);
    for (i = 0; i < 8; i++) {
        data <<= 1;
        digitalWrite(SCL_PIN, HIGH);
        delayMicroseconds(10);
        if (digitalRead(SDA_PIN)) data |= 0x01;
        digitalWrite(SCL_PIN, LOW);
    }
    pinMode(SDA_PIN, OUTPUT);

    digitalWrite(SDA_PIN, (ack == 0) ? LOW : HIGH);
    digitalWrite(SCL_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(SCL_PIN, LOW);
    digitalWrite(SDA_PIN, LOW);

    return data;
}

// I2C总线写入一个字节数据
int i2c_write(unsigned char reg, unsigned char data) {
    i2c_start();
    if (!i2c_write_byte(I2C_ADDR << 1)) return 0;
    if (!i2c_write_byte(reg)) return 0;
    if (!i2c_write_byte(data)) return 0;
    i2c_stop();
    return 1;
}

// I2C总线读取一个字节数据
unsigned char i2c_read(unsigned char reg) {
    unsigned char data;

    i2c_start();
    if (!i2c_write_byte(I2C_ADDR << 1)) return 0;
    if (!i2c_write_byte(reg)) return 0;
    i2c_start();
    if (!i2c_write_byte((I2C_ADDR << 1) | 0x01)) return 0;
    data = i2c_read_byte(0);
    i2c_stop();

    return data;
}

int main() {
    wiringPiSetup();
    i2c_init();

    // 写入数据
    i2c_write(0x10, 0xAB);

    // 读取数据
    unsigned char data = i2c_read(0x10);
    printf("Read data: 0x%X\n", data);

    return 0;
}

注意，这段代码仅作为示例，实际使用时需要根据具体的设备协议进行修改。