切换为软件IIC，完成各种基本函数

inc/i2c.h

@@ -17,14 +17,22 @@
 
 /******************************************************************************/
 
-#define I2C_SPEED 20000
-#define RCU_GPIO_I2C RCU_GPIOF
-#define RCU_I2C RCU_I2C0
-#define I2C_SCL_PORT GPIOF
-#define I2C_SCL_PIN GPIO_PIN_1
-#define I2C_SDA_PORT GPIOF
-#define I2C_SDA_PIN GPIO_PIN_0
-#define I2C_GPIO_AF GPIO_AF_1
+#define I2C_SPEED       20000
+#define RCU_GPIO_I2C    RCU_GPIOF
+#define RCU_I2C         RCU_I2C0
+#define I2C_SCL_PORT    GPIOF
+#define I2C_SCL_PIN     GPIO_PIN_1
+#define I2C_SDA_PORT    GPIOF
+#define I2C_SDA_PIN     GPIO_PIN_0
+#define I2C_GPIO_AF     GPIO_AF_1
+
+/******************************************************************************/
+
+#define I2C_SCL_HIGH()      gpio_bit_set(I2C_SCL_PORT, I2C_SCL_PIN)
+#define I2C_SCL_LOW()       gpio_bit_reset(I2C_SCL_PORT, I2C_SCL_PIN)
+#define I2C_SDA_HIGH()      gpio_bit_set(I2C_SDA_PORT, I2C_SDA_PIN)
+#define I2C_SDA_LOW()       gpio_bit_reset(I2C_SDA_PORT, I2C_SDA_PIN)
+#define I2C_SDA_READ()      gpio_input_bit_get(I2C_SDA_PORT, I2C_SDA_PIN)
 
 /******************************************************************************/
 
@@ -47,6 +55,22 @@ typedef enum {
 
 void i2c_gpio_config(void);
 
+void si2c_config(void);
+
+void i2c_delay(void);
+
+void i2c_start(void);
+
+void i2c_stop(void);
+
+void i2c_send_ack(void);
+
+void i2c_send_nack(void);
+
+uint8_t i2c_wait_ack(void);
+
+
+
 void i2c_config(void);
 
 void i2c_bus_reset(void);

src/i2c.c

@@ -25,6 +25,124 @@ void i2c_gpio_config(void) {
     gpio_output_options_set(I2C_SDA_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SDA_PIN);
 }
 
+void i2c_delay(void) {
+    delay_us(5); // Adjust delay as needed
+}
+
+/*!
+    \brief      configure the software IIC GPIO
+    \param[in]  none
+    \param[out] none
+    \retval     none
+*/
+void si2c_config(void) {
+    rcu_periph_clock_enable(RCU_GPIO_I2C);
+
+    gpio_mode_set(I2C_SCL_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_PULLUP, I2C_SCL_PIN);
+    gpio_output_options_set(I2C_SCL_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SCL_PIN);
+
+    gpio_mode_set(I2C_SDA_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_PULLUP, I2C_SDA_PIN);
+    gpio_output_options_set(I2C_SDA_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SDA_PIN);
+
+    I2C_SCL_HIGH();
+    I2C_SDA_HIGH();
+}
+
+void i2c_start(void) {
+    I2C_SDA_HIGH();
+    I2C_SCL_HIGH();
+    i2c_delay();
+    I2C_SDA_LOW();
+    i2c_delay();
+    I2C_SCL_LOW();
+    // 从全高开始，SCL为高期间，SDA下降沿表示start信号，再拉低SCL
+}
+
+void i2c_stop(void) {
+    I2C_SCL_LOW();
+    I2C_SDA_LOW();
+    i2c_delay();
+    I2C_SCL_HIGH();
+    i2c_delay();
+    I2C_SDA_HIGH();
+    // 从全低开始，SCL为高期间，SDA上升沿表示stop信号，再拉高SCL
+}
+
+void i2c_send_ack(void) {
+    I2C_SDA_LOW();
+    i2c_delay();
+    I2C_SCL_HIGH();
+    i2c_delay();
+    I2C_SCL_LOW();
+    i2c_delay();
+    I2C_SDA_HIGH();
+    // SCL产生一个正常的时钟周期，其间SDA始终为低电平，表示ACK
+}
+
+void i2c_send_nack(void) {
+    I2C_SDA_HIGH();
+    i2c_delay();
+    I2C_SCL_HIGH();
+    i2c_delay();
+    I2C_SCL_LOW();
+    i2c_delay();
+    I2C_SDA_HIGH();
+    // SCL产生一个正常的时钟周期，其间SDA始终为高电平，表示NACK
+}
+
+uint8_t i2c_wait_ack(void) {
+    I2C_SDA_HIGH();
+    i2c_delay();
+    I2C_SCL_HIGH();
+    i2c_delay();
+    uint8_t ack = !I2C_SDA_READ();
+    //ACK信号是第九个时钟期间，SDA被从机在SCL高期间，拉低并保持低电平。此处判断SDA是否被拉低，被拉低则返回0，取反为1，表示收到ACK
+    I2C_SCL_LOW();
+    return ack;
+}
+
+void i2c_send_byte(uint8_t byte) {
+    for (int i = 0; i < 8; i++) {
+        if (byte & 0x80) { //通过&操作获取第一位是1还是0
+            I2C_SDA_HIGH(); //SCL低电平期间，SDA高电平表示1
+        } else {
+            I2C_SDA_LOW(); //SCL低电平期间，SDA低电平表示0
+        }
+        byte <<= 1; //左移一位，把原本第二位的数据移到第一位，再判断高低电平
+        i2c_delay();
+        I2C_SCL_HIGH(); //SCL拉高电平，SDA电平状态保持不变
+        i2c_delay();
+        I2C_SCL_LOW(); //SCL拉低电平
+    }
+    i2c_wait_ack();
+}
+
+uint8_t i2c_receive_byte(uint8_t ack) {
+    uint8_t byte = 0;
+    I2C_SDA_HIGH(); //从高开始
+    for (int i = 0; i < 8; i++) {
+        byte <<= 1;
+        I2C_SCL_HIGH();
+        i2c_delay();
+        if (I2C_SDA_READ()) {
+            byte |= 0x01;
+        }
+        I2C_SCL_LOW();
+        i2c_delay();
+    }
+    if (ack) {
+        i2c_send_ack();
+    } else {
+        i2c_send_nack();
+    }
+    return byte;
+}
+
+
+
+
+
+
 /*!
     \brief      configure the I2CX interface
     \param[in]  none

src/main.c

@@ -56,8 +56,8 @@ int main(void) {
     /* configure LED */
     led_config();
     /* configure I2C */
-    i2c_gpio_config();
-    i2c_config();
+    // i2c_gpio_config();
+    // i2c_config();
 
     // ldc1612_iic_get_sensor_infomation();
     /* configure LDC1612 */