Datasheet

nRF52 ADC

The nRF52832 includes an adjustable 'successive-approximation ADC' which can be configured to convert data with

up to 14-bit resolution (0..16383), and the reference voltage can be adjusted up to 3.6V internally.

The default values for the ADC are 10-bit resolution (0..1023) with a 3.6V reference voltage, meaning every digit

returned from the ADC = 3600mV/1024 = 3.515625mV.

Analog Reference Voltage

The internal reference voltage is 0.6V with a variable gain setting, and can be adjust via the analogReference(...)

function, providing one of the following values:

AR_INTERNAL (0.6V Ref * 6 = 0..3.6V) <-- DEFAULT

AR_INTERNAL_3_0 (0.6V Ref * 5 = 0..3.0V)

AR_INTERNAL_2_4 (0.6V Ref * 4 = 0..2.4V)

AR_INTERNAL_1_8 (0.6V Ref * 3 = 0..1.8V)

AR_INTERNAL_1_2 (0.6V Ref * 2 = 0..1.6V)

AR_VDD4 (VDD/4 REF * 4 = 0..VDD)

For example:

Analog Resolution

The ADC resolution can be set to 8, 10, 12 or 14 bits using the analogReadResolution(...) function, with the default value

being 10-bit:

Default ADC Example (10-bit, 3.6V Reference)

The original source for this code is included in the nRF52 BSP and can be viewed online here (https://adafru.it/zod).

// Set the analog reference to 3.0V (default = 3.6V)

analogReference(AR_INTERNAL_3_0);

// Set the resolution to 12-bit (0..4095)

analogReadResolution(12); // Can be 8, 10, 12 or 14