STM32F407 采样INA226

在STM32F407上采样INA226需要连接STM32F407和INA226，一般通过I2C总线连接。以下是一份用HAL库编写的STM32F407采样INA226的示例代码：

#include "main.h"
#include "i2c.h"
#include "stdio.h"

#define INA226_ADDRESS (0x40) // INA226的I2C地址

// INA226的寄存器地址
#define INA226_REG_CONFIG (0x00)
#define INA226_REG_SHUNTVOLTAGE (0x01)
#define INA226_REG_BUSVOLTAGE (0x02)
#define INA226_REG_POWER (0x03)
#define INA226_REG_CURRENT (0x04)
#define INA226_REG_CALIBRATION (0x05)

// INA226的配置寄存器值
#define INA226_CONFIG_RESET (0x8000)
#define INA226_CONFIG_MODE_SHUNT_BUS_CONTINUOUS (0x7)
#define INA226_CONFIG_VBUSCT_1100US (0x2000)
#define INA226_CONFIG_VSHCT_1100US (0x0800)
#define INA226_CONFIG_AVG_128 (0x0400)
#define INA226_CONFIG_BVOLTAGERANGE_32V (0x200)
#define INA226_CONFIG_GAIN_8_320MV (0x180)
#define INA226_CONFIG_BADCRES_12BIT (0x008)
#define INA226_CONFIG_SADCRES_12BIT_1S_532US (0x007)

// INA226的校准系数（根据具体芯片的参数进行调整）
#define INA226_CALIBRATION_VALUE (4096)

// 定义I2C总线句柄
I2C_HandleTypeDef hi2c1;

// 初始化INA226
void setup_ina226() {
  uint8_t tx_data[3];
  tx_data[0] = INA226_REG_CONFIG;
  tx_data[1] = (INA226_CONFIG_MODE_SHUNT_BUS_CONTINUOUS |
                INA226_CONFIG_VBUSCT_1100US | INA226_CONFIG_VSHCT_1100US |
                INA226_CONFIG_AVG_128 | INA226_CONFIG_BVOLTAGERANGE_32V |
                INA226_CONFIG_GAIN_8_320MV | INA226_CONFIG_BADCRES_12BIT |
                INA226_CONFIG_SADCRES_12BIT_1S_532US) >> 8;
  tx_data[2] = (INA226_CONFIG_MODE_SHUNT_BUS_CONTINUOUS |
                INA226_CONFIG_VBUSCT_1100US | INA226_CONFIG_VSHCT_1100US |
                INA226_CONFIG_AVG_128 | INA226_CONFIG_BVOLTAGERANGE_32V |
                INA226_CONFIG_GAIN_8_320MV | INA226_CONFIG_BADCRES_12BIT |
                INA226_CONFIG_SADCRES_12BIT_1S_532US) & 0xFF;
  HAL_I2C_Master_Transmit(&hi2c1, INA226_ADDRESS << 1, tx_data, 3, 1000);
  HAL_Delay(10);
  uint16_t calibration_value = INA226_CALIBRATION_VALUE;
  tx_data[0] = INA226_REG_CALIBRATION;
  tx_data[1] = calibration_value >> 8;
  tx_data[2] = calibration_value & 0xFF;
  HAL_I2C_Master_Transmit(&hi2c1, INA226_ADDRESS << 1, tx_data, 3, 1000);
}

// 读取INA226的电压值（单位：毫伏）
float read_ina226_voltage() {
  uint8_t tx_data[1] = {INA226_REG_BUSVOLTAGE};
  uint8_t rx_data[2];
  HAL_I2C_Master_Transmit(&hi2c1, INA226_ADDRESS << 1, tx_data, 1, 1000);
  HAL_I2C_Master_Receive(&hi2c1, (INA226_ADDRESS << 1) | 1, rx_data, 2, 1000);
  uint16_t voltage_raw = (rx_data[0] << 8) | rx_data[1];
  // 电压值采用两个补码字节表示，需要转换为实际电压值
  float voltage = (voltage_raw >> 3) * 0.004;
  return voltage;
}

// 读取INA226的电流值（单位：毫安）
float read_ina226_current() {
  uint8_t tx_data[1] = {INA226_REG_CURRENT};
  uint8_t rx_data[2];
  HAL_I2C_Master_Transmit(&hi2c1, INA226_ADDRESS << 1, tx_data, 1, 1000);
  HAL_I2C_Master_Receive(&hi2c1, (INA226_ADDRESS << 1) | 1, rx_data, 2, 1000);
  uint16_t current_raw = (rx_data[0] << 8) | rx_data[1];
  // 电流值采用两个补码字节表示，需要转换为实际电流值
  float current = (int16_t)current_raw * 0.00125;
  return current;
}

int main(void) {
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_I2C1_Init();
  setup_ina226(); // 初始化INA226
  while (1) {
    float voltage = read_ina226_voltage(); // 读取电压值
    float current = read_ina226_current(); // 读取电流值
    printf("voltage: %.3f V, current: %.3f mA\n", voltage, current);
    HAL_Delay(1000);
  }
}

在使用INA226之前，需要先进行初始化，调用`setup_ina226()`函数即可。然后，可以使用`read_ina226_voltage()`函数和`read_ina226_current()`函数分别读取电压和电流数据。这些函数内部使用了HAL库的I2C通信函数`HAL_I2C_Master_Transmit()`和`HAL_I2C_Master_Receive()`来进行I2C通信。在使用时，需要将INA226的I2C地址设置为`INA226_ADDRESS`，并根据具体芯片的参数进行调整`INA226_CALIBRATION_VALUE`的值。