用HAL库写驱动3个ads1115，并对所得的电压值进行滤波。通过串口发送

下面是基于HAL库的ADS1115驱动代码，其中包括了对电压值进行滤波的功能，并通过串口发送：

#include "stm32f4xx_hal.h"
#include "stdio.h"

#define ADS1115_SLAVE_ADDR_1 0x90
#define ADS1115_SLAVE_ADDR_2 0x92
#define ADS1115_SLAVE_ADDR_3 0x94

#define ADS1115_REG_CONFIG 0x01
#define ADS1115_REG_CONVERSION 0x00

#define ADS1115_CONFIG_MUX_SINGLE_0 0x4000
#define ADS1115_CONFIG_MUX_SINGLE_1 0x5000
#define ADS1115_CONFIG_MUX_SINGLE_2 0x6000
#define ADS1115_CONFIG_MUX_SINGLE_3 0x7000

#define ADS1115_CONFIG_PGA_6_144V 0x0000
#define ADS1115_CONFIG_PGA_4_096V 0x0200
#define ADS1115_CONFIG_PGA_2_048V 0x0400
#define ADS1115_CONFIG_PGA_1_024V 0x0600
#define ADS1115_CONFIG_PGA_0_512V 0x0800
#define ADS1115_CONFIG_PGA_0_256V 0x0A00

#define ADS1115_CONFIG_MODE_SINGLE 0x0100
#define ADS1115_CONFIG_DR_860SPS 0x0080
#define ADS1115_CONFIG_CMODE_TRAD 0x0000
#define ADS1115_CONFIG_CPOL_ACTVLOW 0x0000
#define ADS1115_CONFIG_CLAT_NONLAT 0x0000
#define ADS1115_CONFIG_CQUE_1CONV 0x0000

#define ADS1115_CONFIG_DEFAULT 0x8583

#define FILTER_BUF_LEN 10

typedef struct {
  I2C_HandleTypeDef* i2cHandle;
  uint16_t slaveAddr;
  uint16_t config;
  uint16_t conversionValue;
} ADS1115_HandleTypeDef;

void ADS1115_Init(ADS1115_HandleTypeDef* hads, I2C_HandleTypeDef* hi2c,
                  uint16_t slaveAddr, uint16_t config);
void ADS1115_StartConversion(ADS1115_HandleTypeDef* hads);
void ADS1115_ReadConversionValue(ADS1115_HandleTypeDef* hads);
void ADS1115_FilterConversionValue(ADS1115_HandleTypeDef* hads);
void ADS1115_SendConversionValue(ADS1115_HandleTypeDef* hads, UART_HandleTypeDef* huart);

float filterBuf[FILTER_BUF_LEN];
uint8_t filterBufIndex = 0;

int main(void) {
  HAL_Init();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_USART2_CLK_ENABLE();
  __HAL_RCC_I2C1_CLK_ENABLE();

  GPIO_InitTypeDef GPIO_InitStruct = {0};

  GPIO_InitStruct.Pin = GPIO_PIN_2 | GPIO_PIN_3;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
  GPIO_InitStruct.Alternate = GPIO_AF4_I2C1;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  I2C_HandleTypeDef hi2c1 = {0};
  hi2c1.Instance = I2C1;
  hi2c1.Init.ClockSpeed = 400000;
  hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
  hi2c1.Init.OwnAddress1 = 0;
  hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
  hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  hi2c1.Init.OwnAddress2 = 0;
  hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
  HAL_I2C_Init(&hi2c1);

  UART_HandleTypeDef huart2 = {0};
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  HAL_UART_Init(&huart2);

  ADS1115_HandleTypeDef ads1 = {&hi2c1, ADS1115_SLAVE_ADDR_1, ADS1115_CONFIG_DEFAULT, 0};
  ADS1115_HandleTypeDef ads2 = {&hi2c1, ADS1115_SLAVE_ADDR_2, ADS1115_CONFIG_DEFAULT, 0};
  ADS1115_HandleTypeDef ads3 = {&hi2c1, ADS1115_SLAVE_ADDR_3, ADS1115_CONFIG_DEFAULT, 0};

  while (1) {
    ADS1115_StartConversion(&ads1);
    ADS1115_StartConversion(&ads2);
    ADS1115_StartConversion(&ads3);

    ADS1115_ReadConversionValue(&ads1);
    ADS1115_ReadConversionValue(&ads2);
    ADS1115_ReadConversionValue(&ads3);

    ADS1115_FilterConversionValue(&ads1);
    ADS1115_FilterConversionValue(&ads2);
    ADS1115_FilterConversionValue(&ads3);

    ADS1115_SendConversionValue(&ads1, &huart2);
    ADS1115_SendConversionValue(&ads2, &huart2);
    ADS1115_SendConversionValue(&ads3, &huart2);

    HAL_Delay(1000);
  }
}

void ADS1115_Init(ADS1115_HandleTypeDef* hads, I2C_HandleTypeDef* hi2c,
                  uint16_t slaveAddr, uint16_t config) {
  hads->i2cHandle = hi2c;
  hads->slaveAddr = slaveAddr;
  hads->config = config;
  hads->conversionValue = 0;

  uint8_t configBuf[3];
  configBuf[0] = ADS1115_REG_CONFIG;
  configBuf[1] = (uint8_t)(hads->config >> 8);
  configBuf[2] = (uint8_t)(hads->config & 0xFF);
  HAL_I2C_Master_Transmit(hads->i2cHandle, hads->slaveAddr, configBuf, 3, 100);
}

void ADS1115_StartConversion(ADS1115_HandleTypeDef* hads) {
  uint8_t configBuf[3];
  configBuf[0] = ADS1115_REG_CONFIG;
  configBuf[1] = (uint8_t)(hads->config >> 8);
  configBuf[2] = (uint8_t)(hads->config & 0xFF);
  HAL_I2C_Master_Transmit(hads->i2cHandle, hads->slaveAddr, configBuf, 3, 100);
}

void ADS1115_ReadConversionValue(ADS1115_HandleTypeDef* hads) {
  uint8_t readBuf[2];
  HAL_I2C_Master_Transmit(hads->i2cHandle, hads->slaveAddr, (uint8_t*)&ADS1115_REG_CONVERSION, 1, 100);
  HAL_I2C_Master_Receive(hads->i2cHandle, hads->slaveAddr, readBuf, 2, 100);
  hads->conversionValue = ((uint16_t)readBuf[0] << 8) | (uint16_t)readBuf[1];
}

void ADS1115_FilterConversionValue(ADS1115_HandleTypeDef* hads) {
  float voltage = (hads->conversionValue * 6.144) / 32767.0;
  filterBuf[filterBufIndex] = voltage;
  filterBufIndex = (filterBufIndex + 1) % FILTER_BUF_LEN;

  float filteredVoltage = 0.0;
  for (int i = 0; i < FILTER_BUF_LEN; i++) {
    filteredVoltage += filterBuf[i];
  }
  filteredVoltage /= (float)FILTER_BUF_LEN;

  hads->conversionValue = (uint16_t)((filteredVoltage / 6.144) * 32767.0);
}

void ADS1115_SendConversionValue(ADS1115_HandleTypeDef* hads, UART_HandleTypeDef* huart) {
  float voltage = (hads->conversionValue * 6.144) / 32767.0;
  char buf[64];
  snprintf(buf, sizeof(buf), "ADS1115 @ 0x%02X: %f V\r\n", hads->slaveAddr, voltage);
  HAL_UART_Transmit(huart, (uint8_t*)buf, strlen(buf), 100);
}

这段代码初始化了3个ADS1115，使用I2C读取其转换值并进行滤波，最后通过串口发送电压值。在`main()`函数中的`while(1)`循环中，我们每隔1秒读取一次转换值并发送电压值。你可以根据自己的需求更改这些参数。