ADC  8.0
Analog to Digital Conversor library for the Teensy 3.1/3.2 microprocessor
ADC_Module Class Reference

#include <ADC_Module.h>

Classes

struct  ADC_Config
 Store the config of the adc. More...
 

Public Member Functions

 ADC_Module (uint8_t ADC_number, const uint8_t *const a_channel2sc1a, const ADC_NLIST *const a_diff_table, ADC_REGS_t &a_adc_regs)
 Constructor. More...
 
void recalibrate ()
 Starts the calibration sequence, waits until it's done and writes the results. More...
 
void calibrate ()
 Starts the calibration sequence.
 
void wait_for_cal ()
 Waits until calibration is finished and writes the corresponding registers.
 
void setReference (ADC_REFERENCE ref_type)
 Set the voltage reference you prefer, default is vcc. More...
 
void setResolution (uint8_t bits)
 Change the resolution of the measurement. More...
 
uint8_t getResolution ()
 Returns the resolution of the ADC_Module. More...
 
uint32_t getMaxValue ()
 Returns the maximum value for a measurement: 2^res-1. More...
 
void setConversionSpeed (ADC_CONVERSION_SPEED speed)
 Sets the conversion speed (changes the ADC clock, ADCK) More...
 
void setSamplingSpeed (ADC_SAMPLING_SPEED speed)
 Sets the sampling speed. More...
 
void setAveraging (uint8_t num)
 Set the number of averages. More...
 
void enableInterrupts (void(*isr)(void), uint8_t priority=255)
 Enable interrupts. More...
 
void disableInterrupts ()
 Disable interrupts.
 
void enableDMA ()
 Enable DMA request. More...
 
void disableDMA ()
 Disable ADC DMA request.
 
void enableCompare (int16_t compValue, bool greaterThan)
 Enable the compare function to a single value. More...
 
void enableCompareRange (int16_t lowerLimit, int16_t upperLimit, bool insideRange, bool inclusive)
 Enable the compare function to a range. More...
 
void disableCompare ()
 Disable the compare function.
 
void enablePGA (uint8_t gain)
 Enable and set PGA. More...
 
uint8_t getPGA ()
 Returns the PGA level. More...
 
void disablePGA ()
 Disable PGA.
 
void continuousMode ()
 Set continuous conversion mode.
 
void singleMode ()
 Set single-shot conversion mode.
 
void singleEndedMode ()
 Set single-ended conversion mode.
 
void differentialMode ()
 Set differential conversion mode.
 
void setSoftwareTrigger ()
 Use software to trigger the ADC, this is the most common setting.
 
void setHardwareTrigger ()
 Use hardware to trigger the ADC.
 
volatile bool isConverting ()
 Is the ADC converting at the moment? More...
 
volatile bool isComplete ()
 Is an ADC conversion ready? More...
 
volatile bool isDifferential ()
 Is the ADC in differential mode? More...
 
volatile bool isContinuous ()
 Is the ADC in continuous mode? More...
 
volatile bool isPGAEnabled ()
 Is the PGA function enabled? More...
 
bool checkPin (uint8_t pin)
 Check whether the pin is a valid analog pin. More...
 
bool checkDifferentialPins (uint8_t pinP, uint8_t pinN)
 Check whether the pins are a valid analog differential pair of pins. More...
 
void startReadFast (uint8_t pin)
 Starts a single-ended conversion on the pin. More...
 
void startDifferentialFast (uint8_t pinP, uint8_t pinN)
 Starts a differential conversion on the pair of pins. More...
 
int analogRead (uint8_t pin)
 Returns the analog value of the pin. More...
 
int analogRead (ADC_INTERNAL_SOURCE pin)
 Returns the analog value of the special internal source, such as the temperature sensor. More...
 
int analogReadDifferential (uint8_t pinP, uint8_t pinN)
 Reads the differential analog value of two pins (pinP - pinN). More...
 
bool startSingleRead (uint8_t pin)
 Starts an analog measurement on the pin and enables interrupts. More...
 
bool startSingleDifferential (uint8_t pinP, uint8_t pinN)
 Start a differential conversion between two pins (pinP - pinN) and enables interrupts. More...
 
int readSingle ()
 Reads the analog value of a single conversion. More...
 
bool startContinuous (uint8_t pin)
 Starts continuous conversion on the pin. More...
 
bool startContinuousDifferential (uint8_t pinP, uint8_t pinN)
 Starts continuous conversion between the pins (pinP-pinN). More...
 
int analogReadContinuous ()
 Reads the analog value of a continuous conversion. More...
 
void stopContinuous ()
 Stops continuous conversion.
 
void startTimer (uint32_t freq)
 Start the default timer (PDB) triggering the ADC at the frequency. More...
 
void startPDB (uint32_t freq)
 Start PDB triggering the ADC at the frequency. More...
 
void stopTimer ()
 Stop the default timer (PDB)
 
void stopPDB ()
 Stop the PDB.
 
uint32_t getTimerFrequency ()
 Return the default timer's (PDB) frequency. More...
 
uint32_t getPDBFrequency ()
 Return the PDB's frequency. More...
 
void saveConfig (ADC_Config *config)
 
void loadConfig (const ADC_Config *config)
 
void resetError ()
 Resets all errors from the ADC, if any.
 

Public Attributes

struct ADC_Module::ADC_Config adc_config
 
uint8_t adcWasInUse
 Was the adc in use before a call?
 
uint8_t num_measurements
 Number of measurements that the ADC is performing.
 
volatile ADC_ERROR fail_flag
 This flag indicates that some kind of error took place. More...
 
const uint8_t ADC_num
 Which adc is this?
 

Detailed Description

Class ADC_Module: Implements all functions of the Teensy 3.x, LC analog to digital converter

Constructor & Destructor Documentation

◆ ADC_Module()

ADC_Module::ADC_Module ( uint8_t  ADC_number,
const uint8_t *const  a_channel2sc1a,
const ADC_NLIST *const  a_diff_table,
ADC_REGS_t &  a_adc_regs 
)

Constructor.

Pass the ADC number and the Channel number to SC1A number arrays.

Parameters
ADC_numberNumber of the ADC module, from 0.
a_channel2sc1acontains an index that pairs each pin to its SC1A number (used to start a conversion on that pin)
a_diff_tableis similar to a_channel2sc1a, but for differential pins.
a_adc_regspointer to start of the ADC registers

Member Function Documentation

◆ analogRead() [1/2]

int ADC_Module::analogRead ( ADC_INTERNAL_SOURCE  pin)
inline

Returns the analog value of the special internal source, such as the temperature sensor.

It calls analogRead(uint8_t pin) internally, with the correct value for the pin for all boards. Possible values: TEMP_SENSOR, Temperature sensor. VREF_OUT, 1.2 V reference (switch on first using VREF.h). BANDGAP, BANDGAP (switch on first using VREF.h). VREFH, High VREF. VREFL, Low VREF.

Parameters
pinADC_INTERNAL_SOURCE to read.
Returns
the value of the pin.

◆ analogRead() [2/2]

int ADC_Module::analogRead ( uint8_t  pin)

Returns the analog value of the pin.

It waits until the value is read and then returns the result. If a comparison has been set up and fails, it will return ADC_ERROR_VALUE. This function is interrupt safe, so it will restore the adc to the state it was before being called

Parameters
pinpin to read.
Returns
the value of the pin.

◆ analogReadContinuous()

int ADC_Module::analogReadContinuous ( )
inline

Reads the analog value of a continuous conversion.

Set the continuous conversion with with analogStartContinuous(pin) or startContinuousDifferential(pinP, pinN).

Returns
the last converted value. If single-ended and 16 bits it's necessary to typecast it to an unsigned type (like uint16_t), otherwise values larger than 3.3/2 V are interpreted as negative!

◆ analogReadDifferential()

int ADC_Module::analogReadDifferential ( uint8_t  pinP,
uint8_t  pinN 
)

Reads the differential analog value of two pins (pinP - pinN).

It waits until the value is read and then returns the result. If a comparison has been set up and fails, it will return ADC_ERROR_DIFF_VALUE.

Parameters
pinPmust be A10 or A12.
pinNmust be A11 (if pinP=A10) or A13 (if pinP=A12).
Returns
the difference between the pins if they are valid, othewise returns ADC_ERROR_DIFF_VALUE. This function is interrupt safe, so it will restore the adc to the state it was before being called

◆ checkDifferentialPins()

bool ADC_Module::checkDifferentialPins ( uint8_t  pinP,
uint8_t  pinN 
)

Check whether the pins are a valid analog differential pair of pins.

If PGA is enabled it also checks that this ADCx can use PGA on this pins

Parameters
pinPpositive pin to check.
pinNnegative pin to check.
Returns
true if the pin is valid, false otherwise.

◆ checkPin()

bool ADC_Module::checkPin ( uint8_t  pin)

Check whether the pin is a valid analog pin.

Parameters
pinto check.
Returns
true if the pin is valid, false otherwise.

◆ enableCompare()

void ADC_Module::enableCompare ( int16_t  compValue,
bool  greaterThan 
)

Enable the compare function to a single value.

A conversion will be completed only when the ADC value is >= compValue (greaterThan=1) or < compValue (greaterThan=0) Call it after changing the resolution Use with interrupts or poll conversion completion with isComplete()

Parameters
compValuevalue to compare
greaterThantrue or false

◆ enableCompareRange()

void ADC_Module::enableCompareRange ( int16_t  lowerLimit,
int16_t  upperLimit,
bool  insideRange,
bool  inclusive 
)

Enable the compare function to a range.

A conversion will be completed only when the ADC value is inside (insideRange=1) or outside (=0) the range given by (lowerLimit, upperLimit),including (inclusive=1) the limits or not (inclusive=0). See Table 31-78, p. 617 of the freescale manual. Call it after changing the resolution Use with interrupts or poll conversion completion with isComplete()

Parameters
lowerLimitlower value to compare
upperLimitupper value to compare
insideRangetrue or false
inclusivetrue or false

◆ enableDMA()

void ADC_Module::enableDMA ( )

Enable DMA request.

An ADC DMA request will be raised when the conversion is completed (including hardware averages and if the comparison (if any) is true).

◆ enableInterrupts()

void ADC_Module::enableInterrupts ( void(*)(void)  isr,
uint8_t  priority = 255 
)

Enable interrupts.

An IRQ_ADCx Interrupt will be raised when the conversion is completed (including hardware averages and if the comparison (if any) is true).

Parameters
isrfunction (returns void and accepts no arguments) that will be executed after an interrupt.
priorityInterrupt priority, highest is 0, lowest is 255.

◆ enablePGA()

void ADC_Module::enablePGA ( uint8_t  gain)

Enable and set PGA.

Enables the PGA and sets the gain Use only for signals lower than 1.2 V and only in differential mode

Parameters
gaincan be 1, 2, 4, 8, 16, 32 or 64

◆ getMaxValue()

uint32_t ADC_Module::getMaxValue ( )

Returns the maximum value for a measurement: 2^res-1.

Returns
the maximum value for a measurement: 2^res-1.

◆ getPDBFrequency()

uint32_t ADC_Module::getPDBFrequency ( )

Return the PDB's frequency.

Return the PDB's frequency

Returns
the timer's frequency in Hz.

◆ getPGA()

uint8_t ADC_Module::getPGA ( )

Returns the PGA level.

Returns
PGA level from 1 to 64

◆ getResolution()

uint8_t ADC_Module::getResolution ( )

Returns the resolution of the ADC_Module.

Returns
the resolution of the ADC_Module.

◆ getTimerFrequency()

uint32_t ADC_Module::getTimerFrequency ( )
inline

Return the default timer's (PDB) frequency.

The default timer in this board is the PDB, you can also call it directly with getPDBFrequency().

Returns
the timer's frequency in Hz.

◆ isComplete()

volatile bool ADC_Module::isComplete ( )
inline

Is an ADC conversion ready?

Returns
true if yes, false if not. When a value is read this function returns false until a new value exists, so it only makes sense to call it before analogReadContinuous() or readSingle()

◆ isContinuous()

volatile bool ADC_Module::isContinuous ( )
inline

Is the ADC in continuous mode?

Returns
true or false

◆ isConverting()

volatile bool ADC_Module::isConverting ( )
inline

Is the ADC converting at the moment?

Returns
true or false

◆ isDifferential()

volatile bool ADC_Module::isDifferential ( )
inline

Is the ADC in differential mode?

Returns
true or false

◆ isPGAEnabled()

volatile bool ADC_Module::isPGAEnabled ( )
inline

Is the PGA function enabled?

Returns
true or false

◆ loadConfig()

void ADC_Module::loadConfig ( const ADC_Config config)
inline

Load config to the ADC

Parameters
configADC_Config from where the config will be loaded

◆ readSingle()

int ADC_Module::readSingle ( )
inline

Reads the analog value of a single conversion.

Set the conversion with with startSingleRead(pin) or startSingleDifferential(pinP, pinN).

Returns
the converted value.

◆ recalibrate()

void ADC_Module::recalibrate ( )

Starts the calibration sequence, waits until it's done and writes the results.

Usually it's not necessary to call this function directly, but do it if the "environment" changed significantly since the program was started.

◆ saveConfig()

void ADC_Module::saveConfig ( ADC_Config config)
inline

Save config of the ADC to the ADC_Config struct

Parameters
configADC_Config where the config will be stored

◆ setAveraging()

void ADC_Module::setAveraging ( uint8_t  num)

Set the number of averages.

Parameters
numcan be 0, 4, 8, 16 or 32.

It doesn't recalibrate at the end.

◆ setConversionSpeed()

void ADC_Module::setConversionSpeed ( ADC_CONVERSION_SPEED  speed)

Sets the conversion speed (changes the ADC clock, ADCK)

Parameters
speedcan be any from the ADC_CONVERSION_SPEED enum: VERY_LOW_SPEED, LOW_SPEED, MED_SPEED, HIGH_SPEED_16BITS, HIGH_SPEED, VERY_HIGH_SPEED, ADACK_2_4, ADACK_4_0, ADACK_5_2 or ADACK_6_2.

VERY_LOW_SPEED is guaranteed to be the lowest possible speed within specs for resolutions less than 16 bits (higher than 1 MHz), it's different from LOW_SPEED only for 24, 4 or 2 MHz bus frequency. LOW_SPEED is guaranteed to be the lowest possible speed within specs for all resolutions (higher than 2 MHz). MED_SPEED is always >= LOW_SPEED and <= HIGH_SPEED. HIGH_SPEED_16BITS is guaranteed to be the highest possible speed within specs for all resolutions (lower or eq than 12 MHz). HIGH_SPEED is guaranteed to be the highest possible speed within specs for resolutions less than 16 bits (lower or eq than 18 MHz). VERY_HIGH_SPEED may be out of specs, it's different from HIGH_SPEED only for 48, 40 or 24 MHz bus frequency.

Additionally the conversion speed can also be ADACK_2_4, ADACK_4_0, ADACK_5_2 and ADACK_6_2, where the numbers are the frequency of the ADC clock (ADCK) in MHz and are independent on the bus speed. This is useful if you are using the Teensy at a very low clock frequency but want faster conversions, but if F_BUS<F_ADCK, you can't use VERY_HIGH_SPEED for sampling speed.

◆ setReference()

void ADC_Module::setReference ( ADC_REFERENCE  ref_type)

Set the voltage reference you prefer, default is vcc.

Parameters
ref_typecan be ADC_REFERENCE::REF_3V3, ADC_REFERENCE::REF_1V2 (not for Teensy LC) or ADC_REFERENCE::REF_EXT

It recalibrates at the end.

◆ setResolution()

void ADC_Module::setResolution ( uint8_t  bits)

Change the resolution of the measurement.

Parameters
bitsis the number of bits of resolution. For single-ended measurements: 8, 10, 12 or 16 bits. For differential measurements: 9, 11, 13 or 16 bits. If you want something in between (11 bits single-ended for example) select the immediate higher and shift the result one to the right.

Whenever you change the resolution, change also the comparison values (if you use them).

◆ setSamplingSpeed()

void ADC_Module::setSamplingSpeed ( ADC_SAMPLING_SPEED  speed)

Sets the sampling speed.

Increase the sampling speed for low impedance sources, decrease it for higher impedance ones.

Parameters
speedcan be any of the ADC_SAMPLING_SPEED enum: VERY_LOW_SPEED, LOW_SPEED, MED_SPEED, HIGH_SPEED or VERY_HIGH_SPEED.

VERY_LOW_SPEED is the lowest possible sampling speed (+24 ADCK). LOW_SPEED adds +16 ADCK. MED_SPEED adds +10 ADCK. HIGH_SPEED adds +6 ADCK. VERY_HIGH_SPEED is the highest possible sampling speed (0 ADCK added).

◆ startContinuous()

bool ADC_Module::startContinuous ( uint8_t  pin)

Starts continuous conversion on the pin.

It returns as soon as the ADC is set, use analogReadContinuous() to read the value.

Parameters
pincan be any of the analog pins
Returns
true if the pin is valid, false otherwise.

◆ startContinuousDifferential()

bool ADC_Module::startContinuousDifferential ( uint8_t  pinP,
uint8_t  pinN 
)

Starts continuous conversion between the pins (pinP-pinN).

It returns as soon as the ADC is set, use analogReadContinuous() to read the value.

Parameters
pinPmust be A10 or A12.
pinNmust be A11 (if pinP=A10) or A13 (if pinP=A12).
Returns
true if the pins are valid, false otherwise.

◆ startDifferentialFast()

void ADC_Module::startDifferentialFast ( uint8_t  pinP,
uint8_t  pinN 
)

Starts a differential conversion on the pair of pins.

It sets the mux correctly, doesn't do any of the checks on the pin and doesn't change the continuous conversion bit.

Parameters
pinPpositive pin to read.
pinNnegative pin to read.

◆ startPDB()

void ADC_Module::startPDB ( uint32_t  freq)

Start PDB triggering the ADC at the frequency.

Call startSingleRead or startSingleDifferential on the pin that you want to measure before calling this function. See the example adc_pdb.ino.

Parameters
freqis the frequency of the ADC conversion, it can't be lower that 1 Hz

◆ startReadFast()

void ADC_Module::startReadFast ( uint8_t  pin)

Starts a single-ended conversion on the pin.

It sets the mux correctly, doesn't do any of the checks on the pin and doesn't change the continuous conversion bit.

Parameters
pinto read.

◆ startSingleDifferential()

bool ADC_Module::startSingleDifferential ( uint8_t  pinP,
uint8_t  pinN 
)

Start a differential conversion between two pins (pinP - pinN) and enables interrupts.

It returns immediately, get value with readSingle(). If this function interrupts a measurement, it stores the settings in adc_config

Parameters
pinPmust be A10 or A12.
pinNmust be A11 (if pinP=A10) or A13 (if pinP=A12).
Returns
true if the pins are valid, false otherwise.

◆ startSingleRead()

bool ADC_Module::startSingleRead ( uint8_t  pin)

Starts an analog measurement on the pin and enables interrupts.

It returns immediately, get value with readSingle(). If this function interrupts a measurement, it stores the settings in adc_config

Parameters
pinpin to read.
Returns
true if the pin is valid, false otherwise.

◆ startTimer()

void ADC_Module::startTimer ( uint32_t  freq)
inline

Start the default timer (PDB) triggering the ADC at the frequency.

The default timer in this board is the PDB, you can also call it directly with startPDB(). Call startSingleRead or startSingleDifferential on the pin that you want to measure before calling this function. See the example adc_pdb.ino.

Parameters
freqis the frequency of the ADC conversion, it can't be lower that 1 Hz

Member Data Documentation

◆ fail_flag

volatile ADC_ERROR ADC_Module::fail_flag

This flag indicates that some kind of error took place.

Use the defines at the beginning of this file to find out what caused the fail.


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