adc.h File Reference

Defines functions to access ADC peripheral. More...

Functions
void	adc_config (void)
	Initialize the ADC HW block.
void	adc_adcCalibrate (UINT32 refVoltageInMicroVolts, ADC_INPUT_CHANNEL_SEL referenceInput)
	Calibrate the ADC against a known (external) voltage. More...
INT16	adc_readSampleRaw (ADC_INPUT_CHANNEL_SEL channel_idx)
	Read the analog to digital value on a given channel. More...
UINT32	adc_readVoltage (ADC_INPUT_CHANNEL_SEL idx)
	Read the analog to digital value converted to volts on a given channel. More...
ADC_POWER_TYPE	adc_setPower (ADC_POWER_TYPE pwr)
	Powers on/off the ADC HW block. More...
void	adc_SetInputRange (ADC_INPUT_RANGE_SEL range_idx)
	Selects the input range of the ADC input channel. More...
UINT8	adc_convertGPIOtoADCInput (UINT8 gpio)
	Convert GPIO to ADC input channel number. More...
UINT8	adc_convertADCInputtoGPIO (UINT8 adcInput)
	Convert ADC input channel number to GPIO. More...
static INLINE void	adc_setAdcSampleFrequency (ADC_SAMPLE_FREQUENCY sample_frequency)
	Set the sampling frequency to use. More...

Detailed Description

Defines functions to access ADC peripheral.

The ADC provides one-shot conversion of and input analog signal to a digital value (raw or converted to Volts). The maximum sampling rate is 187 KHz with 10 ENOB and the minimum conversion rate is 5.859 KHz.

Function Documentation

void adc_adcCalibrate	(	UINT32	refVoltageInMicroVolts,
		ADC_INPUT_CHANNEL_SEL	referenceInput
	)

Calibrate the ADC against a known (external) voltage.

Parameters

refVoltageInMicroVolts	The voltage of the reference in uV.
referenceInput	The ADC channel to which the reference is connected to.

UINT8 adc_convertADCInputtoGPIO

(

UINT8

adcInput

)

Convert ADC input channel number to GPIO.

Parameters

adcInput

The ADC input channel number.

Returns

The GPIO logical pin number from gpiodriver.h.

UINT8 adc_convertGPIOtoADCInput

(

UINT8

gpio

)

Convert GPIO to ADC input channel number.

Parameters

gpio	The GPIO logical pin number from gpiodriver.h.

Returns

The ADC channel number.

INT16 adc_readSampleRaw

(

ADC_INPUT_CHANNEL_SEL

channel_idx

)

Read the analog to digital value on a given channel.

If the ADC is power off, this function will power it on, read and then power it off.

Parameters

channel_idx

The input channel to read from.

Returns

Raw ADC output.

UINT32 adc_readVoltage

(

ADC_INPUT_CHANNEL_SEL

idx

)

Read the analog to digital value converted to volts on a given channel.

Uncalibrated readings are expected to be within +/-10% while calibrated values are expected to be better than +/-3%. Uses adc_readSampleRaw internally.

Parameters

idx	The input channel to read from.

Returns

The value read in volts, scaled according to the ENOB.

static INLINE void adc_setAdcSampleFrequency ( ADC_SAMPLE_FREQUENCY  sample_frequency )

static

Set the sampling frequency to use.

Default is 5.859 KHz.

Parameters

sample_frequency

The sample frequency to use.

void adc_SetInputRange

(

ADC_INPUT_RANGE_SEL

range_idx

)

Selects the input range of the ADC input channel.

This applies to all channels. Choose a range that will cover all ADC input channels.

Parameters

range_idx

The input range of th signal being measured.

ADC_POWER_TYPE adc_setPower

(

ADC_POWER_TYPE

pwr

)

Powers on/off the ADC HW block.

When reading from a channel, it is not required to power on the ADC before the read.

Parameters

pwr	On or off.

Returns

The previous state.