Constants and function specific to the nRF51 ADC peripheral. More...

#include <nrfcxx/nrf51/impl.hpp>

Inheritance diagram for nrfcxx::nrf5::series::ADC_Peripheral:

Public Types
using	mutex_type = mutex_irq< static_cast< IRQn_Type >(nrf5::ADC.IRQn)>

Static Public Member Functions
static constexpr bool	near_zero (uint16_t v_adc16)
	Test whether a value appears to be indistinguishable from zero. More...

static constexpr unsigned int	make_config (int ain, unsigned int res, unsigned int prescale, unsigned int refsel, unsigned int extrefsel=ADC_CONFIG_EXTREFSEL_None)
	Helper to build up a ADC `CONFIG`. More...

static bool	busy ()
	Return `true` iff the ADC has an in-progress conversion.

static void	trigger ()
	Initiate an ADC sample with the current configuration. More...

static void	enable_bi ()

static void	disable_bi ()

static int	calibrate_bi ()

static int	start_bi ()

static void	stopped_bi ()

Static Public Member Functions inherited from nrfcxx::nrf5::series::ADC_Base
static void	setup_result_bi (volatile uint16_t *ptr, uint16_t maxcnt=1)
	Record the destination address and count of ADC samples. More...

Static Public Attributes
static constexpr IRQn_Type	IRQn = ADC_IRQn

static constexpr unsigned int	VBG_mV = 1200
	nRF51 reference voltage is 1.2 V.

static constexpr uint16_t	TOLERANCE_adc16 = (1U << 7)
	ADC offset error is documented +/- 2%, with a 1.5% error for VBG. More...

static constexpr uint32_t	inten

static uint16_t	result_idx_

Static Public Attributes inherited from nrfcxx::nrf5::series::ADC_Base
static volatile uint16_t *	result_ptr_

static uint16_t	result_maxcnt_

Detailed Description

Constants and function specific to the nRF51 ADC peripheral.

Member Function Documentation

◆ make_config()

static constexpr unsigned int nrfcxx::nrf5::series::ADC_Peripheral::make_config	(	int	ain,
		unsigned int	res,
		unsigned int	prescale,
		unsigned int	refsel,
		unsigned int	extrefsel = `ADC_CONFIG_EXTREFSEL_None`
	)

inlinestaticconstexpr

Helper to build up a ADC CONFIG.

Parameters

ain	a negative value to indicate the input is not from an analog pin, otherwise the ordinal of the AIN used as input. Non-negative values range from 0 through 7 inclusive. When a negative value is used the analog input may subsequently be selected by bitwise-adding the apppriate AIN selection: ADC_CONFIG_PSEL_AnalogInput0 << (ADC_CONFIG_PSEL_Pos + ain)
res	one of: `ADC_CONFIG_RES_8bit` `ADC_CONFIG_RES_9bit` `ADC_CONFIG_RES_10bit`
prescale	one of: `ADC_CONFIG_INPSEL_AnalogInputNoPrescaling` `ADC_CONFIG_INPSEL_AnalogInputTwoThirdsPrescaling` `ADC_CONFIG_INPSEL_AnalogInputOneThirdPrescaling` `ADC_CONFIG_INPSEL_SupplyTwoThirdsPrescaling` `ADC_CONFIG_INPSEL_SupplyOneThirdPrescaling`
refsel	one of: `ADC_CONFIG_REFSEL_VBG` `ADC_CONFIG_REFSEL_External` `ADC_CONFIG_REFSEL_SupplyOneHalfPrescaling` `ADC_CONFIG_REFSEL_SupplyOneThirdPrescaling`
extrefsel	one of: `ADC_CONFIG_EXTREFSEL_None` (default) `ADC_CONFIG_EXTREFSEL_AnalogReference0` `ADC_CONFIG_EXTREFSEL_AnalogReference1`

◆ near_zero()

static constexpr bool nrfcxx::nrf5::series::ADC_Peripheral::near_zero ( uint16_t v_adc16 )

inlinestaticconstexpr

Test whether a value appears to be indistinguishable from zero.

This tests whether a normalized ADC result is within TOLERANCE_adc16 of zero, handling the case where the SAADC result was a small negative that appears as a large unsigned measurement.

Parameters

v_adc16 a normalized ADC result.

Returns: true iff the value is within TOLERANCE_adc16 of zero.

◆ trigger()

static void nrfcxx::nrf5::series::ADC_Peripheral::trigger ( )

inlinestatic

Initiate an ADC sample with the current configuration.

Warning: This function should only be invoked by or on account of the ADC instance that currently owns the ADC peripheral.

Field Documentation

◆ inten

constexpr uint32_t nrfcxx::nrf5::series::ADC_Peripheral::inten

staticconstexpr

Initial value:

= 0

| (ADC_INTENSET_END_Set << ADC_INTENSET_END_Pos)

◆ TOLERANCE_adc16

constexpr uint16_t nrfcxx::nrf5::series::ADC_Peripheral::TOLERANCE_adc16 = (1U << 7)

staticconstexpr

ADC offset error is documented +/- 2%, with a 1.5% error for VBG.

Worst case this would be around bit 5 for an 8-bit acquisition.

In practice SAADC has 9 bits of accuracy, and ADC does much better than SAADC (at least for repeatability). Make this the same as SAADC.

The documentation for this struct was generated from the following file:

nrfcxx/nrf51/impl.hpp

Public Types

Static Public Member Functions

Static Public Attributes