外设初始化

app/inc/hardware.h

@@ -0,0 +1,17 @@
+#ifndef __HARDWARE_H
+#define __HARDWARE_H
+
+
+#define MODBUS_RX_BUF_SIZE  256
+#define MODBUS_USART_BAUDRATE 19200
+
+
+extern uint8_t ModbusRxBuf[MODBUS_RX_BUF_SIZE];
+extern uint16_t ModbusRxLen;
+
+
+
+void MdobusHardwareInit(void);
+
+
+#endif

app/src/hardware.c

@@ -0,0 +1,97 @@
+#include "stm32f4xx.h"
+#include "hardware.h"
+
+uint8_t ModbusRxBuf[MODBUS_RX_BUF_SIZE];
+uint16_t ModbusRxLen = 0;
+
+void ModbusGpioInit(void)
+{
+    GPIO_InitTypeDef GPIO_InitStructure;
+    
+    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
+    
+    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10;
+    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
+    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
+    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
+    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
+    GPIO_Init(GPIOA, &GPIO_InitStructure);
+    
+    GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_USART1);
+    GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_USART1);
+}
+
+void ModbusUsartInit(void)
+{
+    USART_InitTypeDef USART_InitStructure;
+
+    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
+  
+    USART_InitStructure.USART_BaudRate = MODBUS_USART_BAUDRATE;
+    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
+    USART_InitStructure.USART_StopBits = USART_StopBits_1;
+    USART_InitStructure.USART_Parity = USART_Parity_No; 
+    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
+    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
+    USART_Init(USART1, &USART_InitStructure);
+
+    USART_ITConfig(USART1, USART_IT_IDLE, ENABLE);
+    USART_Cmd(USART1, ENABLE);
+}
+
+void ModbusDmaInit(void)
+{
+    DMA_InitTypeDef DMA_InitStructure;
+
+    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
+
+    /* DMA2_Stream2 用于 USART1_RX */
+    DMA_DeInit(DMA2_Stream2);
+    DMA_InitStructure.DMA_Channel = DMA_Channel_4;
+    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&(USART1->DR);
+    DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)ModbusRxBuf;
+    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
+    DMA_InitStructure.DMA_BufferSize = MODBUS_RX_BUF_SIZE;
+    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
+    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
+    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
+    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
+    DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
+    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
+    DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
+    DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_1QuarterFull;
+    DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
+    DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
+    DMA_Init(DMA2_Stream2, &DMA_InitStructure);
+
+    /* DMA2_Stream7 用于 USART1_TX */
+    DMA_DeInit(DMA2_Stream7);
+    DMA_InitStructure.DMA_Channel = DMA_Channel_4;
+    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&(USART1->DR);
+    DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
+    DMA_Init(DMA2_Stream7, &DMA_InitStructure);
+
+    /* 使能USART的DMA请求 */
+    USART_DMACmd(USART1, USART_DMAReq_Rx | USART_DMAReq_Tx, ENABLE);
+    DMA_Cmd(DMA2_Stream2, ENABLE);
+}
+
+void ModbusNvicInit(void)
+{
+    NVIC_InitTypeDef NVIC_InitStructure;
+
+    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
+    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 5; 
+    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
+    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
+    NVIC_Init(&NVIC_InitStructure);
+}
+
+
+void MdobusHardwareInit(void)
+{
+    ModbusGpioInit();
+    ModbusUsartInit();
+    ModbusDmaInit();
+    ModbusNvicInit();
+}