一开始想用硬件I2C,用STM32CubeMX生成的工程,出不来波形。
仿真了一下,确实不对,而且HAL库比较繁琐,不好查问题。
于是改为模拟时序。
SDA接PF1,SCL接PF2。
代码:
- #include "main.h"
- #define uchar unsigned char
- /* Private includes ----------------------------------------------------------*/
- /* USER CODE BEGIN Includes */
- #define SDA_0 HAL_GPIO_WritePin(GPIOF,GPIO_PIN_1,GPIO_PIN_RESET)
- #define SDA_1 HAL_GPIO_WritePin(GPIOF,GPIO_PIN_1,GPIO_PIN_SET)
- #define SCL_0 HAL_GPIO_WritePin(GPIOF,GPIO_PIN_2,GPIO_PIN_RESET)
- #define SCL_1 HAL_GPIO_WritePin(GPIOF,GPIO_PIN_2,GPIO_PIN_SET)
- #define SDA HAL_GPIO_ReadPin(GPIOF,GPIO_PIN_1)
- /* USER CODE END Includes */
- #define PCF8591 0x90 //PCF8591 地址
- /* Private typedef -----------------------------------------------------------*/
- /* USER CODE BEGIN PTD */
- /* USER CODE END PTD */
- /* Private define ------------------------------------------------------------*/
- /* USER CODE BEGIN PD */
- /* USER CODE END PD */
- /* Private macro -------------------------------------------------------------*/
- /* USER CODE BEGIN PM */
- /* USER CODE END PM */
- /* Private variables ---------------------------------------------------------*/
- TIM_HandleTypeDef htim1;
- uchar ack;
- /* USER CODE BEGIN PV */
- /* USER CODE END PV */
- /* Private function prototypes -----------------------------------------------*/
- void SystemClock_Config(void);
- void MX_GPIO_Init(void);
- void MX_TIM1_Init(void);
- void delay_us(uchar x)
- {
- uchar i,j;
- for(i=0;i<x;i++)
- for(j=0;j<8;j++);
- }
- /* USER CODE BEGIN PFP */
- static void SDA_OUTPUT_Init(void)
- {
- GPIO_InitTypeDef GPIO_InitStruct = {0};
- /* USER CODE BEGIN MX_GPIO_Init_1 */
- /* USER CODE END MX_GPIO_Init_1 */
- /* GPIO Ports Clock Enable */
- __HAL_RCC_GPIOF_CLK_ENABLE();
- /*Configure GPIO pin Output Level */
-
- /*Configure GPIO pins : PF0 PF1 */
- GPIO_InitStruct.Pin = GPIO_PIN_1;
- GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
- GPIO_InitStruct.Pull = GPIO_NOPULL;
- GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
- HAL_GPIO_Init(GPIOF, &GPIO_InitStruct);
- /* USER CODE BEGIN MX_GPIO_Init_2 */
- /* USER CODE END MX_GPIO_Init_2 */
- }
- /* USER CODE END PFP */
- static void SDA_INPUT_Init(void)
- {
- GPIO_InitTypeDef GPIO_InitStruct = {0};
- /* USER CODE BEGIN MX_GPIO_Init_1 */
- /* USER CODE END MX_GPIO_Init_1 */
- /* GPIO Ports Clock Enable */
- __HAL_RCC_GPIOF_CLK_ENABLE();
- /*Configure GPIO pin Output Level */
-
- /*Configure GPIO pins : PF0 PF1 */
- GPIO_InitStruct.Pin = GPIO_PIN_1;
- GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
- GPIO_InitStruct.Pull = GPIO_NOPULL;
- GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
- HAL_GPIO_Init(GPIOF, &GPIO_InitStruct);
- /* USER CODE BEGIN MX_GPIO_Init_2 */
- /* USER CODE END MX_GPIO_Init_2 */
- }
- /* Private user code ---------------------------------------------------------*/
- /* USER CODE BEGIN 0 */
- /*******************************************************************
- 起动总线函数
- 函数原型: void Start_I2c();
- 功能: 启动I2C总线,即发送I2C起始条件.
- ********************************************************************/
- void Start_I2c()
- {
-
- SDA_OUTPUT_Init();
- delay_us(1);
- SDA_1; /*发送起始条件的数据信号*/
- delay_us(1);
- SCL_1;
- delay_us(5);
- SDA_0; /*发送起始信号*/
- delay_us(5);
- SCL_0; /*钳住I2C总线,准备发送或接收数据 */
- delay_us(2);
- }
- /*******************************************************************
- 结束总线函数
- 函数原型: void Stop_I2c();
- 功能: 结束I2C总线,即发送I2C结束条件.
- ********************************************************************/
- void Stop_I2c()
- {
- SDA_OUTPUT_Init();
- delay_us(1);
- SDA_0; /*发送结束条件的数据信号*/
- delay_us(1); /*发送结束条件的时钟信号*/
- SCL_1; /*结束条件建立时间大于4μs*/
- delay_us(5);
- SDA_1; /*发送I2C总线结束信号*/
- delay_us(4);
- }
- /*******************************************************************
- 字节数据发送函数
- 函数原型: void SendByte(UCHAR c);
- 功能: 将数据c发送出去,可以是地址,也可以是数据,发完后等待应答,并对
- 此状态位进行操作.(不应答或非应答都使ack=0)
- 发送数据正常,ack=1; ack=0表示被控器无应答或损坏。
- ********************************************************************/
- void SendByte(unsigned char c)
- {
- unsigned char BitCnt;
- SDA_OUTPUT_Init();
- delay_us(1);
- for(BitCnt=0;BitCnt<8;BitCnt++) /*要传送的数据长度为8位*/
- {
- if((c<<BitCnt)&0x80)SDA_1; /*判断发送位*/
- else SDA_0;
- delay_us(1);
- SCL_1; /*置时钟线为高,通知被控器开始接收数据位*/
- delay_us(5);
- SCL_0;
- }
-
- delay_us(2);
- SDA_1; /*8位发送完后释放数据线,准备接收应答位*/
- delay_us(2);
- SCL_1;
- delay_us(3);
- SDA_INPUT_Init();
- delay_us(1);
- if(SDA==1)ack=0;
- else ack=1; /*判断是否接收到应答信号*/
- SCL_0;
- delay_us(2);
- }
- /*******************************************************************
- 字节数据接收函数
- 函数原型: UCHAR RcvByte();
- 功能: 用来接收从器件传来的数据,并判断总线错误(不发应答信号),
- 发完后请用应答函数应答从机。
- ********************************************************************/
- unsigned char RcvByte()
- {
- unsigned char retc;
- unsigned char BitCnt;
- SDA_OUTPUT_Init();
- delay_us(1);
- retc=0;
- SDA_1; /*置数据线为输入方式*/
- for(BitCnt=0;BitCnt<8;BitCnt++)
- {
- delay_us(1);
- SCL_0; /*置时钟线为低,准备接收数据位*/
- delay_us(5);
- SCL_1; /*置时钟线为高使数据线上数据有效*/
- delay_us(2);
- retc=retc<<1;
- SDA_INPUT_Init();
- delay_us(1);
- if(SDA==1)retc=retc+1; /*读数据位,接收的数据位放入retc中 */
- delay_us(2);
- }
- SCL_0;
- delay_us(2);
- return(retc);
- }
- /********************************************************************
- 应答子函数
- 函数原型: void Ack_I2c(bit a);
- 功能: 主控器进行应答信号(可以是应答或非应答信号,由位参数a决定)
- ********************************************************************/
- void Ack_I2c(uchar a)
- {
-
- if(a==0)SDA_0; /*在此发出应答或非应答信号 */
- else SDA_1;
- delay_us(3);
- SCL_1;
- delay_us(5);
- SCL_0; /*清时钟线,钳住I2C总线以便继续接收*/
- delay_us(2);
- }
- /*******************************************************************
- DAC 变换, 转化函数
- *******************************************************************/
- uchar DACconversion(unsigned char sla,unsigned char c, unsigned char Val)
- {
- Start_I2c(); //启动总线
- SendByte(sla); //发送器件地址
- if(ack==0)return(0);
- SendByte(c); //发送控制字节
- if(ack==0)return(0);
- SendByte(Val); //发送DAC的数值
- if(ack==0)return(0);
- Stop_I2c(); //结束总线
- return(1);
- }
- /* USER CODE END 0 */
- /**
- * [url=home.php?mod=space&uid=247401]@brief[/url] The application entry point.
- * @retval int
- */
- int main(void)
- {
- /* USER CODE BEGIN 1 */
- uchar data=0;
- /* USER CODE END 1 */
- /* MCU Configuration--------------------------------------------------------*/
- /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
- HAL_Init();
- /* USER CODE BEGIN Init */
- /* USER CODE END Init */
- /* Configure the system clock */
- SystemClock_Config();
- /* USER CODE BEGIN SysInit */
- /* USER CODE END SysInit */
- /* Initialize all configured peripherals */
- MX_GPIO_Init();
-
- /* USER CODE BEGIN 2 */
- /* USER CODE END 2 */
-
- /* Infinite loop */
- /* USER CODE BEGIN WHILE */
- while (1)
- {
- /* USER CODE END WHILE */
- DACconversion(PCF8591,0x40, data); //DAC 数模转换
- data++;
- HAL_Delay(1);
- /* USER CODE BEGIN 3 */
- }
- /* USER CODE END 3 */
- }
- /**
- * @brief System Clock Configuration
- * @retval None
- */
- void SystemClock_Config(void)
- {
- RCC_OscInitTypeDef RCC_OscInitStruct = {0};
- RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
- /** Configure the main internal regulator output voltage
- */
- if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
- {
- Error_Handler();
- }
- /** Initializes the RCC Oscillators according to the specified parameters
- * in the RCC_OscInitTypeDef structure.
- */
- RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
- RCC_OscInitStruct.MSIState = RCC_MSI_ON;
- RCC_OscInitStruct.MSICalibrationValue = 0;
- RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6;
- RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
- if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
- {
- Error_Handler();
- }
- /** Initializes the CPU, AHB and APB buses clocks
- */
- RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
- |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
- RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
- RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
- RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
- RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
- if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
- {
- Error_Handler();
- }
- }
- /**
- * @brief GPIO Initialization Function
- * @param None
- * @retval None
- */
- static void MX_GPIO_Init(void)
- {
- GPIO_InitTypeDef GPIO_InitStruct = {0};
- /* USER CODE BEGIN MX_GPIO_Init_1 */
- /* USER CODE END MX_GPIO_Init_1 */
- /* GPIO Ports Clock Enable */
- __HAL_RCC_GPIOF_CLK_ENABLE();
- /*Configure GPIO pin Output Level */
- HAL_GPIO_WritePin(GPIOF, GPIO_PIN_2|GPIO_PIN_1, GPIO_PIN_RESET);
- /*Configure GPIO pins : PF0 PF1 */
- GPIO_InitStruct.Pin = GPIO_PIN_2|GPIO_PIN_1;
- GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
- GPIO_InitStruct.Pull = GPIO_NOPULL;
- GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
- HAL_GPIO_Init(GPIOF, &GPIO_InitStruct);
- /* USER CODE BEGIN MX_GPIO_Init_2 */
- /* USER CODE END MX_GPIO_Init_2 */
- }
- /* USER CODE BEGIN 4 */
- /* USER CODE END 4 */
- /**
- * @brief This function is executed in case of error occurrence.
- * @retval None
- */
- void Error_Handler(void)
- {
- /* USER CODE BEGIN Error_Handler_Debug */
- /* User can add his own implementation to report the HAL error return state */
- __disable_irq();
- while (1)
- {
- }
- /* USER CODE END Error_Handler_Debug */
- }
- #ifdef USE_FULL_ASSERT
- /**
- * @brief Reports the name of the source file and the source line number
- * where the assert_param error has occurred.
- * @param file: pointer to the source file name
- * @param line: assert_param error line source number
- * @retval None
- */
- void assert_failed(uint8_t *file, uint32_t line)
- {
- /* USER CODE BEGIN 6 */
- /* User can add his own implementation to report the file name and line number,
- ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
- /* USER CODE END 6 */
- }
- #endif /* USE_FULL_ASSERT */
效果图:
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