能写一个用stm32f407通过spi给ltc6903芯片通信的代码吗
时间: 2023-12-07 13:05:38 浏览: 119
当然可以,以下是一个简单的示例代码:
```c
#include "stm32f4xx.h"
#include "stdio.h"
#define SPIx SPI2
#define SPIx_CLK RCC_APB1Periph_SPI2
#define SPIx_CLK_INIT RCC_APB1PeriphClockCmd
#define SPIx_SCK_PIN GPIO_Pin_13
#define SPIx_SCK_GPIO_PORT GPIOB
#define SPIx_SCK_GPIO_CLK RCC_AHB1Periph_GPIOB
#define SPIx_SCK_SOURCE GPIO_PinSource13
#define SPIx_SCK_AF GPIO_AF_SPI2
#define SPIx_MISO_PIN GPIO_Pin_14
#define SPIx_MISO_GPIO_PORT GPIOB
#define SPIx_MISO_GPIO_CLK RCC_AHB1Periph_GPIOB
#define SPIx_MISO_SOURCE GPIO_PinSource14
#define SPIx_MISO_AF GPIO_AF_SPI2
#define SPIx_MOSI_PIN GPIO_Pin_15
#define SPIx_MOSI_GPIO_PORT GPIOB
#define SPIx_MOSI_GPIO_CLK RCC_AHB1Periph_GPIOB
#define SPIx_MOSI_SOURCE GPIO_PinSource15
#define SPIx_MOSI_AF GPIO_AF_SPI2
#define SPIx_CS_PIN GPIO_Pin_12
#define SPIx_CS_GPIO_PORT GPIOB
#define SPIx_CS_GPIO_CLK RCC_AHB1Periph_GPIOB
void SPIx_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef SPI_InitStructure;
/* Enable GPIO clocks */
RCC_AHB1PeriphClockCmd(SPIx_SCK_GPIO_CLK | SPIx_MISO_GPIO_CLK | SPIx_MOSI_GPIO_CLK, ENABLE);
/* Enable SPI clock */
SPIx_CLK_INIT(SPIx_CLK, ENABLE);
/* Connect SPI pins to AF */
GPIO_PinAFConfig(SPIx_SCK_GPIO_PORT, SPIx_SCK_SOURCE, SPIx_SCK_AF);
GPIO_PinAFConfig(SPIx_MISO_GPIO_PORT, SPIx_MISO_SOURCE, SPIx_MISO_AF);
GPIO_PinAFConfig(SPIx_MOSI_GPIO_PORT, SPIx_MOSI_SOURCE, SPIx_MOSI_AF);
/* Configure SPI pins */
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_Pin = SPIx_SCK_PIN;
GPIO_Init(SPIx_SCK_GPIO_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = SPIx_MISO_PIN;
GPIO_Init(SPIx_MISO_GPIO_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = SPIx_MOSI_PIN;
GPIO_Init(SPIx_MOSI_GPIO_PORT, &GPIO_InitStructure);
/* Configure CS pin */
GPIO_InitStructure.GPIO_Pin = SPIx_CS_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_Init(SPIx_CS_GPIO_PORT, &GPIO_InitStructure);
/* Configure SPI */
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
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_4;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial = 7;
SPI_Init(SPIx, &SPI_InitStructure);
/* Enable SPI */
SPI_Cmd(SPIx, ENABLE);
}
void SPIx_WriteByte(uint8_t byte)
{
/* Wait for TXE */
while (SPI_I2S_GetFlagStatus(SPIx, SPI_I2S_FLAG_TXE) == RESET);
/* Send byte through the SPIx peripheral */
SPI_I2S_SendData(SPIx, byte);
/* Wait for RXNE */
while (SPI_I2S_GetFlagStatus(SPIx, SPI_I2S_FLAG_RXNE) == RESET);
/* Clear RXNE flag */
SPI_I2S_ReceiveData(SPIx);
}
void LTC6903_SetFrequency(uint32_t frequency)
{
uint32_t data;
/* Calculate data to be sent */
data = (frequency << 12) / 1000000UL;
/* Enable CS */
GPIO_ResetBits(SPIx_CS_GPIO_PORT, SPIx_CS_PIN);
/* Send command and data */
SPIx_WriteByte(0x20);
SPIx_WriteByte((data >> 8) & 0xFF);
SPIx_WriteByte(data & 0xFF);
/* Disable CS */
GPIO_SetBits(SPIx_CS_GPIO_PORT, SPIx_CS_PIN);
}
int main(void)
{
/* Initialize SPI */
SPIx_Init();
/* Set frequency to 10MHz */
LTC6903_SetFrequency(10000000UL);
while (1)
{
/* Do something */
}
}
```
在这个示例代码中,我们使用了 STM32F407 的 SPI2 接口来与 LTC6903 芯片进行通信。首先,我们需要进行 SPI 的初始化,包括对 SCK、MISO、MOSI 和 CS 引脚的配置,以及对 SPI 的配置。然后,我们可以通过调用 `SPIx_WriteByte()` 函数,向 LTC6903 发送命令和数据,设置输出频率。在本例中,我们将输出频率设置为 10MHz。
最后,我们需要在主循环中执行一些操作,以便程序不会停止。
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