131 lines
6.3 KiB
Plaintext
131 lines
6.3 KiB
Plaintext
/**
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@page ADC_Regular_injected_groups ADC conversion example showing the usage of
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the 2 ADC groups: regular group for ADC conversions on main stream and
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injected group for ADC conversions limited on specific events (conversions
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injected within main conversions stream),
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using related peripherals (GPIO, DMA, Timer), voltage input from DAC, user
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control by push button and LED
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@verbatim
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******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
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* @file ADC/ADC_Regular_injected_groups/readme.txt
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* @author MCD Application Team
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* @brief Description of the ADC conversion example
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******************************************************************************
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* @attention
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*
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* <h2><center>© Copyright (c) 2016 STMicroelectronics.
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* All rights reserved.</center></h2>
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*
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* This software component is licensed by ST under BSD 3-Clause license,
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* the "License"; You may not use this file except in compliance with the
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* License. You may obtain a copy of the License at:
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* opensource.org/licenses/BSD-3-Clause
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*
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******************************************************************************
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@endverbatim
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@par Example Description
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How to use the ADC peripheral to perform conversions using the two ADC groups:
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regular group for ADC conversions on the main stream, and injected group for
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ADC conversions limited to specific events (conversions injected into the
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main conversion stream).
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One compilation switch is available to select ADC configuration continuous mode
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and external trigger (located in main.h):
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- "ADC_TRIGGER_FROM_TIMER" defined: ADC is operating in not continuous mode
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and conversions are trigger by external trigger: timer.
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- "ADC_TRIGGER_FROM_TIMER" not defined: ADC is operating in continuous mode
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and first conversion is trigger by software trigger.
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One compilation switch is available to generate a waveform voltage
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for test (located in main.h):
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- "WAVEFORM_VOLTAGE_GENERATION_FOR_TEST" defined: For this example purpose, generates a
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waveform voltage on a spare DAC channel (pin PA.04),
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so user has just to connect a wire between DAC channel output and ADC input to run this example.
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- "WAVEFORM_VOLTAGE_GENERATION_FOR_TEST" not defined: no voltage is generated, user has
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to connect a voltage source to the selected ADC channel input to run this example.
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Other peripherals related to ADC are used:
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Mandatory:
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- GPIO peripheral is used in analog mode to drive signal from device pin to
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ADC input.
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Optionally:
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- Timer peripheral is used to trigger ADC conversions.
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- DMA peripheral is used to transfer ADC converted data.
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ADC settings:
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- Regular group:
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Conversion is triggered by external event (timer at 1kHz).
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Number of conversions is set to 1 and continuous mode is disabled: there is
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only 1 conversion at each trigger event.
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- Injected group:
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Conversion is software-triggered by a mere call to HAL_ADCEx_InjectedStart_IT()
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to convert VREFINT channel at each press on user button.
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ADC conversion results:
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- ADC regular conversions results are transferred automatically by DMA, into variable
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array "aADCxConvertedValues".
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- When DMA transfer half-buffer and buffer lengths are reached, callbacks
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HAL_ADC_ConvCpltCallback() and HAL_ADC_ConvCpltCallback() are called.
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- ADC injected conversions results are retrieved upon JEOC interrupt by
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HAL_ADCEx_InjectedConvCpltCallback() function.
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Board settings:
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- ADC is configured to convert ADC_CHANNEL_4 (pin PA.04).
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- Channel configured on regular group:
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The voltage input on ADC channel is provided from DAC channel.
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ADC and DAC channel have been chosen to have the same pad shared at device level: pin PA.04.
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==> Therefore, there is no external connection needed to run this example.
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- Voltage is increasing at each click on push button, from 0 to maximum range in 4 steps.
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Clicks on push button follow circular cycles: At clicks counter maximum value reached, counter is set back to 0.
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- Channel configured on injected group:
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The voltage input is provided from internal reference voltage VrefInt.
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STM32VL-Discovery board's LEDs are be used to monitor the program execution status:
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- Normal operation: LED3 is turned-on/off in function of ADC conversion
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result.
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- Turned-off if voltage measured by injected group is below voltage measured by regular group (average of results table)
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- Turned-on if voltage measured by injected group is above voltage measured by regular group (average of results table)
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- Error: In case of error, LED4 is toggling at a frequency of 1Hz.
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@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
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based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
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a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
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than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
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To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
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@note The application needs to ensure that the SysTick time base is always set to 1 millisecond
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to have correct HAL operation.
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@par Directory contents
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- ADC/ADC_Regular_injected_groups/Inc/stm32f1xx_hal_conf.h HAL configuration file
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- ADC/ADC_Regular_injected_groups/Inc/stm32f1xx_it.h HAL interrupt handlers header file
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- ADC/ADC_Regular_injected_groups/Inc/main.h Header for main.c module
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- ADC/ADC_Regular_injected_groups/Src/stm32f1xx_it.c HAL interrupt handlers
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- ADC/ADC_Regular_injected_groups/Src/main.c Main program
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- ADC/ADC_Regular_injected_groups/Src/stm32f1xx_hal_msp.c HAL MSP file
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- ADC/ADC_Regular_injected_groups/Src/system_stm32f1xx.c STM32F1xx system source file
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@par Hardware and Software environment
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- This example runs on STM32F1xx devices.
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- This example has been tested with STM32VL-Discovery board and can be
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easily tailored to any other supported device and development board.
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@par How to use it ?
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In order to make the program work, you must do the following :
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- Open your preferred toolchain
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- Rebuild all files and load your image into target memory
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- Run the example
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* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
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*/
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