- import serial
- import time
- # 配置串口
- ser = serial.Serial(
- port='/dev/ttyAMA0', # 树莓派的串口设备文件
- baudrate=115200, # 波特率
- bytesize=serial.EIGHTBITS, # 数据位
- parity=serial.PARITY_NONE, # 无校验位
- stopbits=serial.STOPBITS_ONE # 停止位
- )
- try:
- while True:
- # 发送数据
- send_data = 'Hello, STM32!'
- ser.write(send_data.encode())
- print(f'Sent: {send_data}')
- # 接收数据
- if ser.in_waiting > 0:
- receive_data = ser.readline().decode().strip()
- print(f'Received: {receive_data}')
- time.sleep(1)
- except KeyboardInterrupt:
- print('Communication stopped by user.')
- finally:
- ser.close()
- STM32F4:
- #include "main.h"
- #include "usart.h"
- #include "gpio.h"
- uint8_t rx_data;
- void SystemClock_Config(void);
- int main(void)
- {
- HAL_Init();
- SystemClock_Config();
- MX_GPIO_Init();
- MX_USART1_UART_Init();
- while (1)
- {
- // 接收数据
- if (HAL_UART_Receive(&huart1, &rx_data, 1, 100) == HAL_OK)
- {
- // 回显接收到的数据
- HAL_UART_Transmit(&huart1, &rx_data, 1, 100);
- }
- }
- }
- void SystemClock_Config(void)
- {
- RCC_OscInitTypeDef RCC_OscInitStruct = {0};
- RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
- /** Initializes the RCC Oscillators according to the specified parameters
- * in the RCC_OscInitTypeDef structure.
- */
- RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
- RCC_OscInitStruct.HSEState = RCC_HSE_ON;
- RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
- RCC_OscInitStruct.HSIState = RCC_HSI_ON;
- RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
- RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
- RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
- 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_PLLCLK;
- RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
- RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
- RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
- if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
- {
- Error_Handler();
- }
- }
2. SPI通讯
特点:
- 高速全双工通讯,适合需要较高带宽的应用。
- 树莓派作为SPI主机,STM32F4作为从机。
实现步骤:
1. 硬件连接:
- 树莓派的SPI引脚(MOSI、MISO、SCLK、CE0)与STM32F4的SPI引脚(如PA7/MOSI、PA6/MISO、PA5/SCK、PA4/CS)连接。
2. 树莓派配置:
- 启用SPI接口:
选择 `Interfacing Options > SPI > Yes`。
3. STM32F4配置:
- 使用STM32CubeMX配置SPI外设(如SPI1),设置为从机模式。
4. 代码示例:
- 树莓派(Python,使用spidev库):
- import spidev
- spi = spidev.SpiDev()
- spi.open(0, 0) # 打开SPI总线0,设备0
- spi.max_speed_hz = 1000000 # 设置时钟频率
- response = spi.xfer2([0x01, 0x00, 0x00, 0x00]) # 发送并接收数据
- print(response)
- STM32F4:
- <pre style="overflow-wrap: initial; background: rgb(248, 248, 250); border-radius: 4px; font-size: 0.9em; overflow: auto; padding: calc(0.888889em); word-break: initial; color: rgb(25, 27, 31);"><code class="language-text" style="background-color: inherit; border-radius: 0px; font-family: Menlo, Monaco, Consolas, "Andale Mono", "lucida console", "Courier New", monospace; font-size: inherit;">
- void SPI1_Init()
- {
- GPIO_InitTypeDef GPIO_InitStructure;
- SPI_InitTypeDef SPI_InitStructure;
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_SPI1, ENABLE);
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- GPIO_Init(GPIOA, &GPIO_InitStructure);
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
- GPIO_Init(GPIOA, &GPIO_InitStructure);
- SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
- SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
- SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
- SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
- SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
- SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
- SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_8;
- SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
- SPI_Init(SPI1, &SPI_InitStructure);
- SPI_Cmd(SPI1, ENABLE);
- }
- void SPI1_SendData(uint8_t data)
- {
- while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
- SPI_I2S_SendData(SPI1, data);
- }
- uint8_t SPI1_ReceiveData()
- {
- while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
- return SPI_I2S_ReceiveData(SPI1);
- }</code></pre>
3. I2C通讯
特点:
- 多主多从架构,适合连接多个设备。
- 树莓派作为I2C主机,STM32F4作为从机。
实现步骤:
1. 硬件连接:
- 树莓派的I2C引脚(SDA、SCL)与STM32F4的I2C引脚(如PB9/SDA、PB8/SCL)连接。
2. 树莓派配置:
- 启用I2C接口:
```bash
sudo raspi-config
```
选择 `Interfacing Options > I2C > Yes`。
3. STM32F4配置:
- 使用STM32CubeMX配置I2C外设(如I2C1),设置为从机模式,并设置唯一设备地址。
4. 代码示例:
- 树莓派(Python,使用smbus库):
- import smbus
- bus = smbus.SMBus(1) # 使用I2C总线1
- bus.write_byte(0x48, 0x01) # 向地址0x48的设备写入数据
- data = bus.read_byte(0x48) # 从地址0x48的设备读取数据
- print(data)
- STM32F4:
- <pre style="overflow-wrap: initial; background: rgb(248, 248, 250); border-radius: 4px; font-size: 0.9em; overflow: auto; padding: calc(0.888889em); word-break: initial; color: rgb(25, 27, 31);"><code class="language-text" style="background-color: inherit; border-radius: 0px; font-family: Menlo, Monaco, Consolas, "Andale Mono", "lucida console", "Courier New", monospace; font-size: inherit;">void I2C1_Init()
- {
- GPIO_InitTypeDef GPIO_InitStructure;
- I2C_InitTypeDef I2C_InitStructure;
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
- RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- GPIO_Init(GPIOB, &GPIO_InitStructure);
- I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
- I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
- I2C_InitStructure.I2C_OwnAddress1 = 0x00;
- I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
- I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
- I2C_InitStructure.I2C_ClockSpeed = 100000;
- I2C_Init(I2C1, &I2C_InitStructure);
- I2C_Cmd(I2C1, ENABLE);
- }
- void I2C1_WriteData(uint8_t slave_address, uint8_t *data, uint16_t size)
- {
- while (I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));
- I2C_GenerateSTART(I2C1, ENABLE);
- while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
- I2C_Send7bitAddress(I2C1, slave_address, I2C_Direction_Transmitter);
- while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
- while (size--)
- {
- I2C_SendData(I2C1, *data++);
- while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
- }
- I2C_GenerateSTOP(I2C1, ENABLE);
- }
- void I2C1_ReadData(uint8_t slave_address, uint8_t *data, uint16_t size)
- {
- while (I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));
- I2C_GenerateSTART(I2C1, ENABLE);
- while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
- I2C_Send7bitAddress(I2C1, slave_address, I2C_Direction_Receiver);
- while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));
- while (size)
- {
- if (size == 1)
- {
- I2C_AcknowledgeConfig(I2C1, DISABLE);
- I2C_GenerateSTOP(I2C1, ENABLE);
- }
- while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
- *data++ = I2C_ReceiveData(I2C1);
- size--;
- }
- I2C_AcknowledgeConfig(I2C1, ENABLE);
- }</code></pre>
4. 其他通讯方式
- USB通讯:
- STM32F4可以通过USB-OTG接口模拟为虚拟串口(CDC)或HID设备,与树莓派通过USB线直接通讯。
- 以太网/Wi-Fi:
- 树莓派和STM32F4均可通过以太网或Wi-Fi模块(如ESP8266)实现TCP/IP通讯,适合需要长距离或复杂网络协议的场景。
选择建议
简单调试:使用UART串口。
高速数据传输:使用SPI。
多设备连接:使用I2C。
复杂网络应用:使用以太网或Wi-Fi。
注意事项
1. 电平匹配:
- 树莓派的GPIO为3.3V电平,STM32F4通常也为3.3V电平,无需电平转换。
- 如果使用5V设备,需使用电平转换模块。
2. 供电问题:
- 确保树莓派和STM32F4的供电稳定,避免因电流不足导致通讯异常。
3. 调试工具:
- 使用逻辑分析仪或示波器检查信号波形,确保通讯正常。
通过以上方法,可以灵活实现STM32F4与树莓派之间的通讯,满足不同应用场景的需求。