ADC Peripheral Library (PLIB) for Harmony v2
This library allows you to:
- Initialize the ADC module:
- Enable/disable the ADC module
- Select voltage reference sources
- Select input channel and configure the MUX inputs
- Select scan mode; positive and negative analog input channel
- Select conversion clock
- Set the number of the S&H channels to be used
- Control the ADC sampling process:
- Enable/disable sampling
- Select manual or auto-sampling
- Select conversion trigger and sampling time
- Select the number of readings per interrupt
- Select the number of samples in the DMA buffer for each ADC module and select how the DMA will access the ADC buffers
- Control the ADC conversion process:
- Select conversion trigger and sampling time
- Start and terminate conversion process
- Configure channel pair and trigger source
- Configure interrupt control and conversion order
- Format the result buffer:
- Select how conversion results are stored in the buffer
- Select the result format and assign the result sign
- Select the mode: 10-bit or 2-bit
Example Library Functions
| Description | Associated Functions | |
|---|---|---|
| Voltage reference source; enable/disable ADC | PLIB_ADC_VoltageReferenceSelect (MY_ADC_INSTANCE, ADC_REFERENCE_VREFPLUS_TO_AVSS) PLIB_ADC_Enable (MY_ADC_INSTANCE) PLIB_ADC_Disable (MY_ADC_INSTANCE) |
|
| ADC conversion clock | PLIB_ADC_ConversionClockSet (MY_ADC_INSTANCE, 80000000, 320000000) | |
| Input channel selection; MUX A and B inputs | PLIB_ADC_InputSelectPositive (MY_ADC_INSTANCE, ADC_INPUT_POSITIVE_AN2) PLIB_ADC_InputSelectNegative (ADC_ID_1, ADC_INPUTS_NEGATIVE) |
|
| Determine how sampling will occur | PLIB_ADC_SampleAcquisitionTimeSet (MY_ADC_INSTANCE, 2) | |
| Manual or Auto-Sampling | PLIB_ADC_SampleAutoStartEnable (MY_ADC_INSTANCE) PLIB_ADC_SampleAutoStartDisable (MY_ADC_INSTANCE) |
|
| Conversion trigger, sampling time | PLIB_ADC_ConversionStart (MY_ADC_INSTANCE) PLIB_ADC_ConversionClockSourceSelect (MY_ADC_INSTANCE, ADC_CLOCK_SOURCE) PLIB_ADC_ConversionTriggerSourceSelect (MY_ADC_INSTANCE, ADC_CLOCK_SOURCE_SYSTEM_CLOCK) |
|
| Conversion results buffer | PLIB_ADC_ResultBufferModeSelect (MY_ADC_INSTANCE,ADC_BUFFER_MODE_TWO_8WORD_BUFFERS) | |
| Result sign format | PLIB_ADC_ResultFormatSelect (MY_ADC_INSTANCE, ADC_RESULT_FORMAT) | |
| Number of readings per interrupt | PLIB_ADC_SamplesPerInterruptSelect (MY_ADC_INSTANCE, ADC_16SAMPLES_PER_INTERRUPT) | |
| Number of samples in the DMA buffer for each ADC; how the DMA will access the ADC buffers | PLIB_ADC_DMAEnable (MY_ADC_INSTANCE) PLIB_ADC_DMADisable (MY_ADC_INSTANCE) PLIB_ADC_DMAInputBufferSelect (MY_ADC_INSTANCE, ADC_DMA_INPUT_BUFFER_1WORD) |
|
| 10-bit or 12-bit mode | PLIB_ADC_ResultSizeSelect (MY_ADC_INSTANCE, ADC_RESULT_SIZE_10_BITS) | |
| Channel pair configuration | PLIB_ADC_PairTriggerSourceSelect (MY_ADC_INSTANCE, ADC_PAIR_AN0_AN1,ADC_CONVERSION_TRIGGER_TMR3_COMPARE_MATCH) | |
| Misc. ADC functions: • Asynchronous sampling selection • Conversion order selection • Global software trigger control |
PLIB_ADC_AsynchronousDedicatedSamplingEnable (MY_ADC_INSTANCE) PLIB_ADC_AsynchronousDedicatedSamplingDisable (MY_ADC_INSTANCE) PLIB_ADC_GlobalSoftwareTriggerSet (MY_ADC_INSTANCE) | |
NOTE: MY_ADC_INSTANCE is the ADC instance selected for use by the application developer. E.g.,
#define MY_ADC_INSTANCE DRV_ADC_INDEX_0
int main ( )
{….}
DRV_ADC_INDEX is the ADC module's index number macro, defined in the DRV_ADC header file. These provide the ADC index definitions. E.g.,
#define DRV_ADC_INDEX_0 0
Important notes on using this library:
- The MPLAB® Harmony PLIB Overview provides more details and background on PLIB usage
- Peripheral Libraries are only supported for internal (on board) microcontroller peripherals. External peripherals are always connected to the microcontroller through one or more internal peripheral interfaces and therefore, do not require peripheral library support.