基于stm32的 ads1120驱动代码

以下是一个基于STM32的ADS1120驱动代码示例：

#include "stm32f10x.h"

#define ADS1120_CS_Pin GPIO_Pin_4
#define ADS1120_CS_Port GPIOA

void ADS1120_Init(void);
void ADS1120_Write_Register(uint8_t reg, uint8_t value);
uint8_t ADS1120_Read_Register(uint8_t reg);
void ADS1120_Start_Conversion(void);
int32_t ADS1120_Read_Data(void);

int main(void)
{
    SystemInit();
    GPIO_InitTypeDef GPIO_InitStructure;

    /* Enable GPIOA clock */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

    /* Configure ADS1120 CS pin as output push-pull */
    GPIO_InitStructure.GPIO_Pin = ADS1120_CS_Pin;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(ADS1120_CS_Port, &GPIO_InitStructure);

    /* Initialize ADS1120 */
    ADS1120_Init();

    /* Start conversion */
    ADS1120_Start_Conversion();

    while(1)
    {
        /* Read data */
        int32_t data = ADS1120_Read_Data();
        /* Do something with the data */
    }
}

void ADS1120_Init(void)
{
    /* Set CS high */
    GPIO_SetBits(ADS1120_CS_Port, ADS1120_CS_Pin);
    /* Initialize SPI */
    SPI_InitTypeDef SPI_InitStructure;
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
    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_8;
    SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
    SPI_InitStructure.SPI_CRCPolynomial = 7;
    SPI_Init(SPI1, &SPI_InitStructure);
    SPI_Cmd(SPI1, ENABLE);
    /* Reset ADS1120 */
    ADS1120_Write_Register(0x00, 0x06);
    /* Configure ADS1120 */
    ADS1120_Write_Register(0x01, 0x00); // Gain = 1
    ADS1120_Write_Register(0x02, 0x20); // Data rate = 20 SPS
    ADS1120_Write_Register(0x03, 0x00); // Disable internal reference
}

void ADS1120_Write_Register(uint8_t reg, uint8_t value)
{
    /* Set CS low */
    GPIO_ResetBits(ADS1120_CS_Port, ADS1120_CS_Pin);
    /* Send register address */
    SPI_I2S_SendData(SPI1, reg);
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
    /* Send register value */
    SPI_I2S_SendData(SPI1, value);
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
    /* Set CS high */
    GPIO_SetBits(ADS1120_CS_Port, ADS1120_CS_Pin);
}

uint8_t ADS1120_Read_Register(uint8_t reg)
{
    uint8_t value;
    /* Set CS low */
    GPIO_ResetBits(ADS1120_CS_Port, ADS1120_CS_Pin);
    /* Send register address */
    SPI_I2S_SendData(SPI1, reg);
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
    /* Dummy write to receive register value */
    SPI_I2S_SendData(SPI1, 0x00);
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
    /* Read register value */
    value = SPI_I2S_ReceiveData(SPI1);
    /* Set CS high */
    GPIO_SetBits(ADS1120_CS_Port, ADS1120_CS_Pin);
    return value;
}

void ADS1120_Start_Conversion(void)
{
    /* Set CS low */
    GPIO_ResetBits(ADS1120_CS_Port, ADS1120_CS_Pin);
    /* Send start conversion command */
    SPI_I2S_SendData(SPI1, 0x08);
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
    /* Set CS high */
    GPIO_SetBits(ADS1120_CS_Port, ADS1120_CS_Pin);
}

int32_t ADS1120_Read_Data(void)
{
    int32_t data;
    /* Set CS low */
    GPIO_ResetBits(ADS1120_CS_Port, ADS1120_CS_Pin);
    /* Send read data command */
    SPI_I2S_SendData(SPI1, 0x10);
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
    /* Dummy write to receive data */
    SPI_I2S_SendData(SPI1, 0x00);
    while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET);
    /* Read data */
    data = ((int32_t)SPI_I2S_ReceiveData(SPI1) << 24) | ((int32_t)SPI_I2S_ReceiveData(SPI1) << 16) | ((int32_t)SPI_I2S_ReceiveData(SPI1) << 8) | (int32_t)SPI_I2S_ReceiveData(SPI1);
    /* Set CS high */
    GPIO_SetBits(ADS1120_CS_Port, ADS1120_CS_Pin);
    return data;
}

在代码中，我们使用了STM32的SPI模块来与ADS1120进行通信。在初始化函数中，我们首先将ADS1120的CS引脚设置为输出并拉高，然后初始化SPI模块并将ADS1120进行复位。接着，我们配置ADS1120的增益、数据速率和参考电压，并在开始转换函数中发送启动转换命令。在读取数据函数中，我们首先发送读取数据命令，然后接收32位数据并返回。注意，ADS1120的数据格式为补码，因此需要进行符号扩展。