stm32f103c8 硬件spi1 max6675
时间: 2023-11-26 20:10:33 浏览: 41
STM32F103C8是一款Cortex-M3内核的微控制器,具有丰富的外设资源,包括多个SPI接口。MAX6675是一款热电偶温度传感器,可以通过SPI接口与STM32F103C8进行通信。
硬件SPI1的最大时钟频率取决于芯片的主频和SPI时钟分频系数,通常在几十MHz的范围内。在使用硬件SPI1与MAX6675通信时,需要配置SPI1的工作模式、时钟相位、时钟极性、数据位数等参数,同时根据MAX6675的通信协议进行数据传输。以下是一个简单的代码示例:
```c
#include "stm32f10x.h"
#define SPI1_CS_PIN GPIO_Pin_4
#define SPI1_CS_PORT GPIOA
void SPI1_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef SPI_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1 | RCC_APB2Periph_GPIOA, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = SPI1_CS_PIN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_Init(SPI1_CS_PORT, &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_High;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_Init(SPI1, &SPI_InitStructure);
SPI_Cmd(SPI1, ENABLE);
}
uint16_t MAX6675_ReadTemp(void)
{
uint8_t txData[2] = {0};
uint8_t rxData[2] = {0};
uint16_t temp = 0;
txData[0] = 0x00;
txData[1] = 0x00;
GPIO_ResetBits(SPI1_CS_PORT, SPI1_CS_PIN);
SPI_I2S_SendData(SPI1, txData[0]);
while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
rxData[0] = SPI_I2S_ReceiveData(SPI1);
SPI_I2S_SendData(SPI1, txData[1]);
while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
rxData[1] = SPI_I2S_ReceiveData(SPI1);
GPIO_SetBits(SPI1_CS_PORT, SPI1_CS_PIN);
temp = (rxData[0] << 8) | rxData[1];
return temp >> 3;
}
int main(void)
{
uint16_t temp = 0;
SPI1_Init();
while(1)
{
temp = MAX6675_ReadTemp();
// 处理温度数据
}
}
```