DOUBT IN ADC CONFIGURATION

[NANDHU]

HI ,

•  I want to configure P0.02  as an adc channel .
•  I also want to read the adc value from P0.02 at regular intervals.
•  For regular intervals i will put a timer and inside the timer handler function i will call the function for reading adc value .

My doubts

1. which  are function using to configure or initializing  the adc ?
2. which function is using  for  read the the adc value?

SDK i am using "nRF5_SDK_14.2.0_17b948a".

I am configuring  adc for battery level detection .

Please answer to  1 and 2

[awneil]

NANDHU said:

SDK i am using "nRF5_SDK_14.2.0_17b948a

Why are you using an old SDK ?

Have you looked at the SAADC example in the SDK ?

[NANDHU]

HI,

    Actually our product is 2d-3d combinational mouse .

• so we are using "ble_app_hids_mouse" application from  nRF5_SDK_14.2.0_17b948a
• so i want to configure the adc to it.
• awneil said:

  Have you looked at the SAADC example in the SDK ?
• yes i looked it 

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

void saadc_init(void)
{
ret_code_t err_code;
nrf_saadc_channel_config_t channel_config =
NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN0);

err_code = nrf_drv_saadc_init(NULL, saadc_callback);
APP_ERROR_CHECK(err_code);

err_code = nrf_drv_saadc_channel_init(0, &channel_config);
APP_ERROR_CHECK(err_code);

err_code = nrf_drv_saadc_buffer_convert(m_buffer_pool[0], SAMPLES_IN_BUFFER);
APP_ERROR_CHECK(err_code);

err_code = nrf_drv_saadc_buffer_convert(m_buffer_pool[1], SAMPLES_IN_BUFFER);
APP_ERROR_CHECK(err_code);

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

1. Is the above function if  enough for intilization?
2. How we can read the adc value which function is using for it . I didn't saw any function which returns converted adc value . please help me.

[awneil]

NANDHU said:

i looked it

Don't just look it - build it, run it, and see what it does!

How to properly post source code:

[NANDHU]

Hi awneil

    I just want to known from where or using which function   we get the adc value.

• The converted analog to digital value is storing to where and from where we can read it ?just tell me that 

[Simon]

Take a look at the saadc_callback(), the SAADC input data can be found in p_event->data.done.p_buffer[] (after nrf_drv_saadc_buffer_convert() is called)

Best regards,

Simon

[NANDHU]

Hi Simon

In the adc init function nrf_drv_saadc_buffer_convert()  is calling twice . Can explain why these function is calling in the init part.

1. Is it for assigning the buffer for storing adc value?
2. When the code execution is entering to saadc_callback().Is it entering to saadc_callback() after calling "nrf_drv_saadc_sample " function or "nrf_drv_saadc_sample_task_get" function