SAADC changing value range (signed to unsigned)

[Duy]

Hello Nordic Support,

I am using SAADC on nRF52840 with nRF5_SDK_15.3.0_59ac345. 

I use the following configurations:

{ 
    .resolution         = (nrf_saadc_resolution_t)NRFX_SAADC_CONFIG_RESOLUTION, // 12 bits
    .oversample         = (nrf_saadc_oversample_t)NRFX_SAADC_CONFIG_OVERSAMPLE, // 0
    .interrupt_priority = NRFX_SAADC_CONFIG_IRQ_PRIORITY,                       // 5
    .low_power_mode     = NRFX_SAADC_CONFIG_LP_MODE                             // 0
}


{                                                   
    .resistor_p = NRF_SAADC_RESISTOR_DISABLED,      
    .resistor_n = NRF_SAADC_RESISTOR_DISABLED,      
    .gain       = NRF_SAADC_GAIN1_6,                
    .reference  = NRF_SAADC_REFERENCE_INTERNAL,     
    .acq_time   = NRF_SAADC_ACQTIME_10US,           
    .mode       = NRF_SAADC_MODE_SINGLE_ENDED,      
    .burst      = NRF_SAADC_BURST_DISABLED,         
    .pin_p      = (nrf_saadc_input_t)(NRF_SAADC_INPUT_AIN1),       
    .pin_n      = NRF_SAADC_INPUT_DISABLED          
}

The SAADC value, as I have been using is signed. I wonder if Nordic will later support unsigned value, or you will not? Or are there any ways to convert from signed SAADC to unsigned SAADC?

Thank you and best regards,

           Duy

[Jared]

Hi,

The SAADC stores samples as 16 bits 2's complement, I don't know of any future plans to implement unsigned SAADC atm. Why would you need to store the samples as unsigned SAADC? The SAADC can be used in differential mode if you want to sample something not relative to local ground.

regards

Jared