// 零点校准（输出0V时的数字码）
void zero_calibration(void) {
    uint32_t mid_code = 0x80000;    // 中间码
    set_dac_output(mid_code);
    
    // 使用高精度电压表测量实际输出
    float measured_voltage = read_voltmeter();
    
    // 计算零点偏移
    zero_offset = measured_voltage;
    
    // 存储校准参数到EEPROM
    save_calibration_data();
}

// 满量程校准
void fullscale_calibration(void) {
    uint32_t full_code = 0xFFFFF;   // 满量程码
    set_dac_output(full_code);
    
    float measured_voltage = read_voltmeter();
    
    // 计算增益误差
    gain_error = (measured_voltage - 10.0) / 10.0;
    
    save_calibration_data();
}