帮我写一段ARM-M4的MCU上SPI主机接收的代码
时间: 2024-05-11 17:17:21 浏览: 8
好的,以下是一个简单的ARM-M4的MCU上SPI主机接收的代码示例:
```c
#include "stm32f4xx.h"
#define SPI1_CS_PIN GPIO_Pin_4
#define SPI1_CS_PORT GPIOA
void spi_init(void) {
GPIO_InitTypeDef GPIO_InitStruct;
SPI_InitTypeDef SPI_InitStruct;
// Enable the SPI1 clock
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
// Enable the GPIOA clock
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
// Configure GPIO pins for SPI1
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStruct);
// Connect SPI1 pins to AF5
GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_SPI1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_SPI1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_SPI1);
// Configure SPI1
SPI_InitStruct.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_InitStruct.SPI_Mode = SPI_Mode_Master;
SPI_InitStruct.SPI_DataSize = SPI_DataSize_8b;
SPI_InitStruct.SPI_CPOL = SPI_CPOL_High;
SPI_InitStruct.SPI_CPHA = SPI_CPHA_2Edge;
SPI_InitStruct.SPI_NSS = SPI_NSS_Soft;
SPI_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_8;
SPI_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStruct.SPI_CRCPolynomial = 7;
SPI_Init(SPI1, &SPI_InitStruct);
// Enable SPI1
SPI_Cmd(SPI1, ENABLE);
}
uint8_t spi_read_byte(void) {
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
return SPI_I2S_ReceiveData(SPI1);
}
void spi_select_slave(void) {
GPIO_ResetBits(SPI1_CS_PORT, SPI1_CS_PIN);
}
void spi_deselect_slave(void) {
GPIO_SetBits(SPI1_CS_PORT, SPI1_CS_PIN);
}
int main(void) {
uint8_t data;
// Initialize SPI
spi_init();
// Select slave
spi_select_slave();
// Read data
data = spi_read_byte();
// Deselect slave
spi_deselect_slave();
while (1);
}
```
这段代码初始化了SPI1作为主机,读取了从机发送的一个字节的数据,并在读取后取消选择从机。你可以根据你的具体需求进行修改和扩展。