/**
@page ADC_Sequencer ADC conversion example using related peripherals (GPIO, DMA), voltage input from DAC, user control by user button and LED
@verbatim
******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
* @file ADC/ADC_Sequencer/readme.txt
* @author MCD Application Team
* @brief Description of the ADC conversion example
******************************************************************************
* @attention
*
* Copyright (c) 2016 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
@endverbatim
@par Example Description
How to use the ADC peripheral with a sequencer to convert several channels.
The channels converted are, in order, one external channel and two internal
channels (VrefInt and temperature sensors).
Next, voltages and temperature are computed.
WAVEFORM_VOLTAGE_GENERATION_FOR_TEST compilation switch (located in main.h) is
available to generate a waveform voltage for the test :
- "WAVEFORM_VOLTAGE_GENERATION_FOR_TEST" defined: waveform voltage for test is generated
on DAC_CHANNEL_1 (output pin PA.04) by DAC peripheral.
If ADC channel and DAC channel are selected on the same GPIO (default configuration
in this example):
connection is done internally in GPIO pad, user has nothing to connect.
If ADC channel and DAC channel are selected on two different GPIO:
user has just to connect a wire between DAC channel output and ADC input to run this example.
- "WAVEFORM_VOLTAGE_GENERATION_FOR_TEST" not defined: no voltage is generated, user has
to connect a voltage source to the selected ADC channel input to run this example
Other peripherals related to ADC are used:
Mandatory:
- GPIO peripheral is used in analog mode to drive signal from device pin to
ADC input.
Optionally:
- DMA peripheral is used to transfer ADC converted data.
ADC settings:
Sequencer is enabled and set to convert 3 ranks (3 channels) in discontinuous
mode, one by one, each conversion being software-triggered.
ADC conversion results:
- ADC conversions results are transferred automatically by DMA, into variable
array "aADCxConvertedValues".
- Each entry of this array contains one of the converted data of the ADC sequencer three ranks.
- When DMA transfer half-buffer and buffer lengths are reached, callbacks
HAL_ADC_ConvHalfCpltCallback() and HAL_ADC_ConvCpltCallback() are called.
- When the ADC sequence is complete (the three ADC conversions are carried out),
the voltages and temperature are computed and stored in variables:
uhADCChannelToDAC_mVolt, uhVrefInt_mVolt, wTemperature_DegreeCelsius.
Board settings:
- ADC rank 1 is configured to convert ADC_CHANNEL_4 (pin PA.04).
If compilation switch "WAVEFORM_VOLTAGE_GENERATION_FOR_TEST" is defined, the voltage input on ADC channel comes
from the DAC channel. This means that pins PA.04 and PA.04 must
be connected by a wire.
- The voltage input on ADC channel is provided from DAC channel.
ADC and DAC channel have been chosen to have the same pad shared at device level: pin PA.04.
==> Therefore, there is no external connection needed to run this example.
- Voltage is increasing at each click on user button, from 0 to maximum range in 4 steps.
Clicks on user button follow circular cycles: At clicks counter maximum value reached, counter is set back to 0.
Channels on sequencer ranks 2 and 3 are ADC internal channels: no external connection is required.
To observe voltage level applied on ADC channel through GPIO, connect a voltmeter on
pin PA.04 (Arduino connector CN8 pin A2, Morpho connector CN7 pin 32).
STM32F091RC-Nucleo RevC board's LED is be used to monitor the program execution status:
- Normal operation: LED2 is turned-on/off with respect to ADC conversion results.
- Turned-off if sequencer has not yet converted all ranks
- Turned-on if sequencer has converted all ranks
- Error: In case of error, LED2 is toggling at a frequency of 1Hz.
@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
@note The application needs to ensure that the SysTick time base is always set to 1 millisecond
to have correct HAL operation.
@par Directory contents
- ADC/ADC_Sequencer/Inc/stm32f0xx_hal_conf.h HAL configuration file
- ADC/ADC_Sequencer/Inc/stm32f0xx_it.h DMA interrupt handlers header file
- ADC/ADC_Sequencer/Inc/main.h Header for main.c module
- ADC/ADC_Sequencer/Src/stm32f0xx_it.c DMA interrupt handlers
- ADC/ADC_Sequencer/Src/main.c Main program
- ADC/ADC_Sequencer/Src/stm32f0xx_hal_msp.c HAL MSP file
- ADC/ADC_Sequencer/Src/system_stm32f0xx.c STM32F0xx system source file
@par Hardware and Software environment
- This example runs on STM32F0xx devices.
- This example has been tested with STM32F091RC-Nucleo RevC board and can be
easily tailored to any other supported device and development board.
@par How to use it ?
In order to make the program work, you must do the following :
- Open your preferred toolchain
- Rebuild all files and load your image into target memory
- Run the example
*/
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