ADC

This section describes the programming interfaces of the Analog-to-Digital Converter (ADC) HAL driver. More...

Overview

This section describes the programming interfaces of the Analog-to-Digital Converter (ADC) HAL driver.

Terms and acronyms

The following provides descriptions to the terms commonly used in the ADC driver and how to use its various functions.

Terms	Details
ADC	ADC is an Analog-to-Digital Converter that converts a continuous physical quantity (usually voltage) to a digital number that represents the quantity's amplitude.

Supported features

The ADC is a Successive Approximation ADC . The supported channels vary based on the actual MCU devices used. Resolution of ADC is 12 bits.

• Retrieve ADC data for a channel.
  Call hal_adc_get_data_polling() function to get data for a channel. Only one sample data is retrieved at a time.

How to use this driver

• Use ADC driver to gets sample data for a channel.
  
  • Step1: Call hal_gpio_init() to initialize the pin.
  • Step2: Call hal_pinmux_set_function() to set ADC pinmux if the EPT is not used.
  • Step3: Call hal_gpio_set_direction() to set the related pin's direction as input if the EPT is not used.
  • Step4: Call hal_gpio_disable_pull() to disable pull state of the related pin if the EPT is not used.
  • Step5: Call hal_adc_init() to initialize the ADC module.
  • Step6: Call hal_adc_get_data_polling() to retrieve sample data for a channel.
  • Step7: Call hal_adc_deinit() to return the ADC module back to its original state.
  • Sample code:

    uint32_t adc_data;
    hal_gpio_init(HAL_GPIO_0);
    hal_pinmux_set_function(HAL_GPIO_0, 2);//Set GPIO 0 to an ADC work mode. For more details, please refer to hal_pinmux_set_function().
    hal_gpio_set_direction(HAL_GPIO_0, HAL_GPIO_DIRECTION_INPUT);//Set GPIO 0 direction as input.
    hal_gpio_disable_pull(HAL_GPIO_0);//Disable pull of GPIO 0.
    hal_adc_init();//Initialize ADC module.
    hal_adc_get_data_polling(HAL_ADC_CHANNEL_11, &adc_data);//Retrieve ADC data for channel 11.
    hal_adc_deinit();//Deinit ADC module when job done.

Functions
hal_adc_status_t	hal_adc_init (void)
	ADC init function. More...
hal_adc_status_t	hal_adc_deinit (void)
	ADC deinit function. More...
hal_adc_status_t	hal_adc_get_data_polling (hal_adc_channel_t channel, uint32_t *data)
	ADC receives a sample data for a channel. More...

Modules
	Enum

Function Documentation

hal_adc_status_t hal_adc_deinit

(

void

)

ADC deinit function.

This function resets the ADC peripheral registers to their default values.

Returns

HAL_ADC_STATUS_OK, ADC deinit success.
HAL_ADC_STATUS_ERROR, ADC clock disable failed.

hal_adc_status_t hal_adc_get_data_polling	(	hal_adc_channel_t	channel,
		uint32_t *	data
	)

ADC receives a sample data for a channel.

Parameters

[in]	channel	is the channel that will be sampled. This parameter can only be the value of type hal_adc_channel_t.
[out]	data	is the raw data of the channel.

Returns

HAL_ADC_STATUS_OK, ADC get data success.
HAL_ADC_STATUS_ERROR_CHANNEL, the channel number is invalid.
HAL_ADC_STATUS_INVALID_PARAMETER, data is NULL.

Example

Sample code please refer to Use ADC driver to get sample data for a channel of How to use this driver

hal_adc_status_t hal_adc_init

(

void

)

ADC init function.

Returns

HAL_ADC_STATUS_OK, ADC init success.
HAL_ADC_STATUS_ERROR_BUSY, ADC is busy.
HAL_ADC_STATUS_ERROR, ADC clock enable failed.