2017-07-24 336 views
1

STM32F072CBU微控制器。使用STM32F0 ADC单独读取不同的输入

我有多个输入到ADC,并希望分别读取它们和单独。 STMcubeMX生成样板代码,假设我希望依次读取所有输入,并且我还无法弄清楚如何解决这个问题。

This blog post表达了我遇到的同样的问题,但所给出的解决方案似乎不起作用。每次转换打开和关闭ADC都与返回值中的错误相关。只有当我在STMcubeMX中配置单个ADC输入,然后在不去初始化ADC的情况下进行轮询时,才会返回准确的读数。

cubeMX的adc_init功能:

/* ADC init function */ 
static void MX_ADC_Init(void) 
{ 

    ADC_ChannelConfTypeDef sConfig; 

    /**Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion) 
    */ 
    hadc.Instance = ADC1; 
    hadc.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV4; 
    hadc.Init.Resolution = ADC_RESOLUTION_12B; 
    hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT; 
    hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD; 
    hadc.Init.EOCSelection = ADC_EOC_SINGLE_CONV; 
    hadc.Init.LowPowerAutoWait = DISABLE; 
    hadc.Init.LowPowerAutoPowerOff = DISABLE; 
    hadc.Init.ContinuousConvMode = DISABLE; 
    hadc.Init.DiscontinuousConvMode = DISABLE; 
    hadc.Init.ExternalTrigConv = ADC_SOFTWARE_START; 
    hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE; 
    hadc.Init.DMAContinuousRequests = DISABLE; 
    hadc.Init.Overrun = ADC_OVR_DATA_PRESERVED; 
    if (HAL_ADC_Init(&hadc) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    /**Configure for the selected ADC regular channel to be converted. 
    */ 
    sConfig.Channel = ADC_CHANNEL_0; 
    sConfig.Rank = ADC_RANK_CHANNEL_NUMBER; 
    sConfig.SamplingTime = ADC_SAMPLETIME_41CYCLES_5; 
    if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    /**Configure for the selected ADC regular channel to be converted. 
    */ 
    sConfig.Channel = ADC_CHANNEL_1; 
    if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    /**Configure for the selected ADC regular channel to be converted. 
    */ 
    sConfig.Channel = ADC_CHANNEL_2; 
    if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    /**Configure for the selected ADC regular channel to be converted. 
    */ 
    sConfig.Channel = ADC_CHANNEL_3; 
    if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    /**Configure for the selected ADC regular channel to be converted. 
    */ 
    sConfig.Channel = ADC_CHANNEL_4; 
    if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    /**Configure for the selected ADC regular channel to be converted. 
    */ 
    sConfig.Channel = ADC_CHANNEL_TEMPSENSOR; 
    if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    /**Configure for the selected ADC regular channel to be converted. 
    */ 
    sConfig.Channel = ADC_CHANNEL_VREFINT; 
    if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

} 

的main.c

int main(void) 
{ 

    /* USER CODE BEGIN 1 */ 

    /* USER CODE END 1 */ 

    /* MCU Configuration----------------------------------------------------------*/ 

    /* Reset of all peripherals, Initializes the Flash interface and the Systick. */ 
    HAL_Init(); 

    /* USER CODE BEGIN Init */ 

    /* USER CODE END Init */ 

    /* Configure the system clock */ 
    SystemClock_Config(); 

    /* USER CODE BEGIN SysInit */ 

    /* USER CODE END SysInit */ 

    /* Initialize all configured peripherals */ 
    MX_GPIO_Init(); 
    MX_ADC_Init(); 
    MX_USART1_UART_Init(); 

    /* USER CODE BEGIN 2 */ 
    //HAL_TIM_Base_Start_IT(&htim3); 
    init_printf(NULL, putc_wrangler); 
    HAL_ADCEx_Calibration_Start(&hadc); 
    HAL_ADC_DeInit(&hadc); // ADC is initialized for every channel change 
    schedule_initial_events(); 
    /* USER CODE END 2 */ 

    /* Infinite loop */ 
    /* USER CODE BEGIN WHILE */ 
    event_loop(); 
    /* USER CODE END WHILE */ 

    /* USER CODE BEGIN 3 */ 

    /* USER CODE END 3 */ 

} 

我的过程中,现在为关闭ADC关闭并重新初始化切换频道:

// Set up 
    ADC_ChannelConfTypeDef channelConfig; 

    channelConfig.SamplingTime = samplingT; 
    channelConfig.Channel = sensorChannel; 
    channelConfig.Rank = ADC_RANK_CHANNEL_NUMBER; 

    if (HAL_ADC_Init(&hadc) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    if (HAL_ADC_ConfigChannel(&hadc, &channelConfig) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

// Convert 
    uint16_t retval; 

    if (HAL_ADC_Start(&hadc) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    if (HAL_ADC_PollForConversion(&hadc, 1) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    if (HAL_ADC_GetError(&hadc) != HAL_ADC_ERROR_NONE) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

    retval = (uint16_t) HAL_ADC_GetValue(&hadc); 

    if (HAL_ADC_Stop(&hadc) != HAL_OK) 
    { 
    _Error_Handler(__FILE__, __LINE__); 
    } 

// Close 
    HAL_ADC_DeInit(&hadc); 

此时我不确定有什么方法可以实现我想要的,STM32似乎已经无法启动ADC线位于常规组中并按顺序转换。

+0

我担心这是HAL问题。我编程自己的登记方式,我从来没有注意到这样的事情。但是您必须记住,ADC输入具有相当大的电容,如果您的转换时间很短,则需要提供合适的电流来加载它。否则,您可能会遇到类似问题。解决方案是 - 更长的转换或输入上的缓冲区。 –

+0

谢谢@PeterJ。我想这就是我害怕的;我认为从HAL中分离出来会带来麻烦,因为它具有一些脆弱的状态机,并且想要控制,但是看起来好像没有办法像这样配置不同的输入。我会研究直接注册方法,看看可以做些什么。 – ctag

回答

1

如果您想在单次转换模式下读取多个ADC通道,则必须在每次读取之前更改通道设置,但不必重新初始化ADC。只需按照以下步骤操作,选择新频道(如果频道必须不同,但通常可以相同,则可以更改采样时间),选择频道等级,然后调用HAL_ADC_ConfigChannel函数。在此之后,您可以执行转换。

void config_ext_channel_ADC(uint32_t channel, boolean_t val) 
{ 
    ADC_ChannelConfTypeDef sConfig; 

    sConfig.Channel = channel; 
    sConfig.SamplingTime = ADC_SAMPLETIME_71CYCLES_5; 

    if(True == val) 
    { 
    sConfig.Rank = ADC_RANK_CHANNEL_NUMBER; 
    } 
    else 
    { 
    sConfig.Rank = ADC_RANK_NONE; 
    } 

    HAL_ADC_ConfigChannel(&hadc, &sConfig); 
} 

uint32_t r_single_ext_channel_ADC(uint32_t channel) 
{ 
    uint32_t digital_result; 

    config_ext_channel_ADC(channel, True); 

    HAL_ADCEx_Calibration_Start(&hadc); 

    HAL_ADC_Start(&hadc); 
    HAL_ADC_PollForConversion(&hadc, 1000); 
    digital_result = HAL_ADC_GetValue(&hadc); 
    HAL_ADC_Stop(&hadc); 

    config_ext_channel_ADC(channel, False); 

    return digital_result; 
} 

一个实例为使用:

#define SUPPLY_CURRENT ADC_CHANNEL_5 
#define BATTERY_VOLTAGE ADC_CHANNEL_6 

uint16_t r_battery_voltage(uint16_t mcu_vcc) 
{ 
    float vbat; 
    uint16_t digital_val; 

    digital_val = r_single_ext_channel_ADC(BATTERY_VOLTAGE); 
    vbat = (mcu_vcc/4095.0) * digital_val; 
    vbat = vbat * 2;   // 1/2 voltage divider 

    return vbat; 
} 

uint16_t r_supply_current(uint16_t mcu_vcc) 
{ 
    float v_sense, current; 
    uint16_t digital_val; 

    digital_val = r_single_ext_channel_ADC(SUPPLY_CURRENT); 
    v_sense = (mcu_vcc/4095.0) * digital_val; 
    current = v_sense * I_SENSE_GAIN; 

    return current; 
} 

此代码是上STM32F030使用。为了读取内部温度传感器和参考电压,必须设置附加使能位时所需的上述功能的略微不同的版本。为MCU VDD计算

void config_int_channel_ADC(uint32_t channel, boolean_t val) 
{ 
    ADC_ChannelConfTypeDef sConfig; 
    sConfig.Channel = channel; 

    if(val == True) 
    { 
    if(channel == ADC_CHANNEL_VREFINT) 
    { 
     ADC->CCR |= ADC_CCR_VREFEN; 
     hadc.Instance->CHSELR = (uint32_t)(ADC_CHSELR_CHSEL17); 
    } 
    else if(channel == ADC_CHANNEL_TEMPSENSOR) 
    { 
     ADC->CCR |= ADC_CCR_TSEN; 
     hadc.Instance->CHSELR = (uint32_t)(ADC_CHSELR_CHSEL16); 
    } 

    sConfig.Rank   = ADC_RANK_CHANNEL_NUMBER; 
    sConfig.SamplingTime = ADC_SAMPLETIME_239CYCLES_5; 
    } 
    else if(val == False) 
    { 
    if(channel == ADC_CHANNEL_VREFINT) 
    { 
     ADC->CCR &= ~ADC_CCR_VREFEN; 
     hadc.Instance->CHSELR = 0; 
    } 
    else if(channel == ADC_CHANNEL_TEMPSENSOR) 
    { 
     ADC->CCR &= ~ADC_CCR_TSEN; 
     hadc.Instance->CHSELR = 0; 
    } 

    sConfig.Rank   = ADC_RANK_NONE; 
    sConfig.SamplingTime = ADC_SAMPLETIME_239CYCLES_5; 
    } 

    HAL_ADC_ConfigChannel(&hadc,&sConfig); 
} 

uint32_t r_single_int_channel_ADC(uint32_t channel) 
{ 
    uint32_t digital_result; 

    config_int_channel_ADC(channel, True); 

    HAL_ADCEx_Calibration_Start(&hadc); 

    HAL_ADC_Start(&hadc); 
    HAL_ADC_PollForConversion(&hadc, 1000); 
    digital_result = HAL_ADC_GetValue(&hadc); 
    HAL_ADC_Stop(&hadc); 

    config_int_channel_ADC(channel, False); 

    return digital_result; 
} 

实施例的使用内部参考电压:

#define VREFINT_CAL_ADDR ((uint16_t*) ((uint32_t) 0x1FFFF7BA)) 

static float FACTORY_CALIB_VDD = 3.31; 

uint16_t calculate_MCU_vcc() 
{ 
    float analog_Vdd; 
    uint16_t val_Vref_int = r_single_int_channel_ADC(ADC_CHANNEL_VREFINT); 

    analog_Vdd = (FACTORY_CALIB_VDD * (*VREFINT_CAL_ADDR))/val_Vref_int; 

    return analog_Vdd * 1000; 
} 

内部温度传感器读数:

#define TEMP30_CAL_ADDR ((uint16_t*) ((uint32_t) 0x1FFFF7B8)) 
#define TEMP110_CAL_ADDR ((uint16_t*) ((uint32_t) 0x1FFFF7C2)) 

static float FACTORY_CALIB_VDD = 3.31; 

float r_MCU_temp(uint16_t mcu_vcc) 
{ 
    float temp; 
    float slope = ((110.0 - 30.0)/((*TEMP110_CAL_ADDR) - (*TEMP30_CAL_ADDR))); 

    uint16_t ts_data = r_single_int_channel_ADC(ADC_CHANNEL_TEMPSENSOR); 

    temp = ((mcu_vcc/FACTORY_CALIB_VDD) * ts_data)/1000; 
    temp = slope * (temp - (*TEMP30_CAL_ADDR)) + 30; 

    return round_to(temp, 0); 
} 

注意,校准数据地址可能是你的MCU不同,检查数据表以获取更多信息。