GD32 I2C — I2C 主机接收 2 字节

Tue, 08 Sep 2026 14:52:21 +0800

I2C — I2C 主机接收 2 字节

固件库: GD32F30x_Firmware_Library V3.0.3
芯片: GD32
源文件: GD32F30x_Firmware_Library_V3.0.3/Examples/I2C/Master_receiver_two_bytes/main.c

功能简介

本示例演示 I2C 总线通信。I2C 只需两根线（SCL+SDA）就能连接多个设备，是最常用的低速通信总线。

硬件准备

I2C 从设备（如 EEPROM、传感器模块）
SCL/SDA 线上需要 4.7K 上拉电阻

完整代码

#include "gd32f30x.h"
#define I2C0_OWN_ADDRESS7      0x72
#define I2C0_SLAVE_ADDRESS7    0x82

void rcu_config(void);
void gpio_config(void);
void i2c_config(void);

/*!
    \brief      main function
    \param[in]  none
    \param[out] none
    \retval     none
*/
int main(void)
{
    uint8_t i;

    /* cofigure RCU */
    rcu_config();
    /* cofigure GPIO */
    gpio_config();
    /* cofigure I2C */
    i2c_config();

    i = 0;
    /* send a NACK for the next data byte which will be received into the shift register */
    i2c_ackpos_config(I2C0, I2C_ACKPOS_NEXT);
    /* wait until I2C bus is idle */
    while(i2c_flag_get(I2C0, I2C_FLAG_I2CBSY));
    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C0);
    /* wait until SBSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_SBSEND));
    /* send slave address to I2C bus */
    i2c_master_addressing(I2C0, I2C0_SLAVE_ADDRESS7, I2C_RECEIVER);
    /* disable ACK before clearing ADDSEND bit */
    i2c_ack_config(I2C0, I2C_ACK_DISABLE);
    /* wait until ADDSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND));
    /* clear ADDSEND bit */
    i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
    /* Wait until the last data byte is received into the shift register */
    while(!i2c_flag_get(I2C0, I2C_FLAG_BTC));
    /* wait until the RBNE bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_RBNE));

    /* read a data from I2C_DATA */
    i2c_receiver[i++] = i2c_data_receive(I2C0);
    /* wait until the RBNE bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_RBNE));
    /* read a data from I2C_DATA */
    i2c_receiver[i++] = i2c_data_receive(I2C0);
    /* send a stop condition */
    i2c_stop_on_bus(I2C0);
    /* wait until stop condition generate */
    while(I2C_CTL0(I2C0) & 0x0200);
    i2c_ackpos_config(I2C0, I2C_ACKPOS_CURRENT);
    /* enable acknowledge */
    i2c_ack_config(I2C0, I2C_ACK_ENABLE);

    while(1) {
    }
}

void rcu_config(void)
{
    /* enable GPIOB clock */
    rcu_periph_clock_enable(RCU_GPIOB);
    /* enable I2C0 clock */
    rcu_periph_clock_enable(RCU_I2C0);
}

void gpio_config(void)
{
    /* connect PB6 to I2C0_SCL */
    /* connect PB7 to I2C0_SDA */
    gpio_init(GPIOB, GPIO_MODE_AF_OD, GPIO_OSPEED_50MHZ, GPIO_PIN_6 | GPIO_PIN_7);
}

void i2c_config(void)
{
    /* cofigure I2C clock */
    i2c_clock_config(I2C0, 100000, I2C_DTCY_2);
    /* cofigure I2C address */
    i2c_mode_addr_config(I2C0, I2C_I2CMODE_ENABLE, I2C_ADDFORMAT_7BITS, I2C0_OWN_ADDRESS7);
    /* enable I2C0 */
    i2c_enable(I2C0);
    /* enable acknowledge */
    i2c_ack_config(I2C0, I2C_ACK_ENABLE);
}

代码讲解

GPIO 配置：设置引脚为输出/输入模式，选择推挽/开漏输出，配置上拉/下拉。

I2C 配置：设置通信速率（标准 100K / 快速 400K / 快速+ 1M）、从机地址、时钟拉伸。

实验现象

主机和从机完成数据收发
校验通过 LED 指示成功

注意事项

I2C 总线需要上拉电阻（一般 4.7K）
从机地址要与设备手册一致（注意 7 位/8 位地址的区别）
写 EEPROM 后需要等待 5ms 以上再读

Master_receiver_two_bytes on CLing

GD32 I2C — I2C 主机接收 2 字节

I2C — I2C 主机接收 2 字节

功能简介

硬件准备

完整代码

代码讲解

实验现象

注意事项