STM32的HAL库软件模拟IIC

softiic.h

 1 #ifndef __SOFTI2C_H_
 2 #define __SOFTI2C_H_
 3 
 4 #include "main.h"
 5 //使用IICX   PD6,PC1
 6 
 7 #define SDA_IN()  {GPIOC->MODER &= ~(3 << 1 * 2);GPIOC->MODER = (0 << 1 * 2);}
 8 #define SDA_OUT() {GPIOC->MODER &= ~(3 << 1 * 2);GPIOC->MODER = (1 << 1 * 2);}
 9 
10 //IO操作函数     
11 #define i2c_scl_low()    HAL_GPIO_WritePin(GPIOD, GPIO_PIN_6, GPIO_PIN_RESET)
12 #define i2c_scl_high()   HAL_GPIO_WritePin(GPIOD, GPIO_PIN_6, GPIO_PIN_SET)
13 
14 #define i2c_sda_low()    HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_RESET)
15 #define i2c_sda_high()   HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_SET)
16 
17 #define i2c_read_sda()   HAL_GPIO_ReadPin(GPIOC, GPIO_PIN_1)
18 
19 extern uint32_t delay1us;
20 
21 void delay_1us(uint32_t delay_1us);
22 
23 void analog_i2c_delay(void);
24 
25 void bsp_analog_i2c_init(void);
26 
27 void bsp_analog_i2c_start(void);
28 
29 void bsp_analog_i2c_stop(void);
30 
31 uint8_t bsp_analog_i2c_wait_ack(void);
32 
33 void bsp_analog_i2c_ack(void);
34 
35 void bsp_analog_i2c_nack(void);
36 
37 void bsp_analog_i2c_send_byte(uint8_t data);
38 
39 uint8_t bsp_analog_i2c_read_byte(void);
40 
41 #endif

soft.c

  1 #include "softi2c.h"
  2 
  3 uint32_t delay1us;
  4 
  5 /** 
  6  * @brief: 1us延时
  7  * @param {uint32_t} delay_1us
  8  * @return {*}
  9  */
 10 void delay_1us(uint32_t delay_1us)
 11 {
 12     HAL_TIM_Base_Start_IT(&htim3);
 13     delay1us = delay_1us;
 14     while (delay1us);
 15     HAL_TIM_Base_Stop_IT(&htim3);
 16 }
 17 
 18 /** 
 19  * @brief: IIC延时时间
 20  * @return {*}
 21  */
 22 void analog_i2c_delay(void)
 23 {
 24     delay_1us(2);
 25 }
 26 
 27 /** 
 28  * @brief: 软件模拟I2C初始化
 29  * @return {*}
 30  */
 31 void bsp_analog_i2c_init(void)
 32 {
 33     GPIO_InitTypeDef GPIO_InitStruct = {0};
 34 
 35     __HAL_RCC_GPIOD_CLK_ENABLE();
 36     __HAL_RCC_GPIOC_CLK_ENABLE();
 37 
 38     /*Configure GPIO pins : PD6 */
 39     GPIO_InitStruct.Pin = GPIO_PIN_6;
 40     GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
 41     GPIO_InitStruct.Pull = GPIO_NOPULL;
 42     GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
 43     HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
 44     
 45     /*Configure GPIO pins : PC1 */
 46     GPIO_InitStruct.Pin = GPIO_PIN_1;
 47     GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
 48     GPIO_InitStruct.Pull = GPIO_NOPULL;
 49     GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
 50     HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
 51 
 52     bsp_analog_i2c_stop();
 53 }
 54 
 55 /** 
 56  * @brief: I2C 开始,SCL为高电平的时候SDA产生一个下降沿信号
 57  * @return {*}
 58  */
 59 void bsp_analog_i2c_start(void)
 60 {
 61     /*    _____
 62      *SDA      \_____________
 63      *    __________
 64      *SCL           \________
 65      */
 66     i2c_sda_high();
 67     i2c_scl_high();
 68     analog_i2c_delay();
 69     i2c_sda_low();
 70     analog_i2c_delay();
 71     i2c_scl_low();
 72     analog_i2c_delay();
 73 }
 74 
 75 /** 
 76  * @brief: I2C 停止,SCL为高电平的时候SDA产生一个上升沿信号
 77  * @return {*}
 78  */
 79 void bsp_analog_i2c_stop(void)
 80 {
 81     /*               _______
 82      *SDA __________/
 83      *          ____________
 84      *SCL _____/
 85      */
 86     i2c_sda_low();
 87     i2c_scl_high();
 88     analog_i2c_delay();
 89     i2c_sda_high();
 90     analog_i2c_delay();
 91 }
 92 
 93 /** 
 94  * @brief: I2C 等待响应
 95  * @return {*}
 96  */
 97 uint8_t bsp_analog_i2c_wait_ack(void)
 98 {
 99     uint32_t timeout = 0;
100 
101     i2c_sda_high();
102     SDA_IN();
103     analog_i2c_delay();
104     i2c_scl_high();
105     analog_i2c_delay();
106     while(i2c_read_sda())
107     {
108         timeout++;
109         if(timeout > 2000)
110         {
111             return 1;
112         }
113     }
114     i2c_scl_low();
115     analog_i2c_delay();
116     return 0;
117 }
118 
119 /** 
120  * @brief: I2C 响应
121  * @return {*}
122  */
123 void bsp_analog_i2c_ack(void)
124 {
125     /*           ____
126      *SCL ______/    \______
127      *    ____         _____
128      *SDA     \_______/
129      */
130     i2c_sda_low();
131     analog_i2c_delay();
132     i2c_scl_high();
133     analog_i2c_delay();
134     i2c_scl_low();
135     analog_i2c_delay();
136     i2c_sda_high();
137 }
138 
139 /** 
140  * @brief: I2C 不响应
141  * @return {*}
142  */
143 void bsp_analog_i2c_nack(void)
144 {
145     /*           ____
146      *SCL ______/    \______
147      *    __________________
148      *SDA
149      */
150     i2c_sda_high();
151     analog_i2c_delay();
152     i2c_scl_high();
153     analog_i2c_delay();
154     i2c_scl_low();
155     analog_i2c_delay();
156 }
157 
158 /** 
159  * @brief: I2C 发送一个字节数据
160  * @param {uint8_t} data
161  * @return {*}
162  */
163 void bsp_analog_i2c_send_byte(uint8_t data)
164 {
165     uint8_t i;
166 
167     SDA_OUT();
168     for(i = 0; i < 8; i++)
169     {
170         if(data & 0x80)
171         {
172            i2c_sda_high();
173         }
174         else
175         {
176             i2c_sda_low();
177         }
178 
179         analog_i2c_delay();
180         i2c_scl_high();
181         analog_i2c_delay();
182         i2c_scl_low();
183         if(i == 7)
184         {
185             i2c_sda_high();
186         }
187         data <<= 1;
188         analog_i2c_delay();
189     }
190 }
191 
192 /** 
193  * @brief: I2C 读一个字节数据
194  * @return {*}
195  */
196 uint8_t bsp_analog_i2c_read_byte(void)
197 {
198     uint8_t i, data = 0;
199 
200     i2c_sda_high();
201     SDA_IN();
202     for(i = 0; i < 8; i++ )
203     {
204         data <<= 1;
205         i2c_scl_high();
206         analog_i2c_delay();
207         if(i2c_read_sda())
208         {
209             data++;
210         }
211         i2c_scl_low();
212         analog_i2c_delay();
213     }
214 
215     return data;
216 }

部分改写，原处：https://blog.csdn.net/weixin_43808708/article/details/126961103