117 lines
5.3 KiB
Plaintext
117 lines
5.3 KiB
Plaintext
/**
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@page ADC_AnalogWatchdog ADC conversion example with analog watchdog, using
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related peripherals (GPIO, DMA, Timer), voltage input from DAC, user control
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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_AnalogWatchdog/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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* Copyright (c) 2016 STMicroelectronics.
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* All rights reserved.
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*
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* This software is licensed under terms that can be found in the LICENSE file
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* in the root directory of this software component.
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* If no LICENSE file comes with this software, it is provided AS-IS.
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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 with an analog watchdog
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and out-of-window interrupts enabled.
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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 DAC_CHANNEL_1 (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 conversion are triggered by external event (timer at 1kHz).
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- Continuous mode is disabled to yield only 1 conversion at each conversion trigger.
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- Analog watchdog 1 is enabled, minimum and maximum thresholds are respectively set
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to 1/8 and 5/8 of full range scale (between 0.41V and 2.06V with full range of 3.3V).
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ADC conversion results:
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- ADC conversions results are transferred automatically by DMA, into variable
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array "aADCxConvertedValues".
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- DMA and ADC are configured to operate continuously, in circular mode.
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When DMA transfer half-buffer and full buffer lengths are reached, callbacks
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HAL_ADC_ConvHalfCpltCallback() and HAL_ADC_ConvCpltCallback() are called.
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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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- Apply an analog voltage on pin PA.04 and click on push button to update the ADC
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analog watchdog result on STM32F103RB-Nucleo board LED.
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Note: This example, on some other STM32 boards, is using DAC to generate an analog voltage to ADC input.
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On STM32F103RB-Nucleo, the device has no DAC available, therefore analog signal must be supplied externally.
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STM32F103RB-Nucleo board LED is be used to monitor the program execution status:
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- Normal operation: LED2 is turned-on/off in function of ADC conversion
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result.
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- Turned-off if voltage into of AWD window
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- Turned-on if voltage is out of AWD window
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- Error: In case of error, LED2 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_AnalogWatchdog/Inc/stm32f1xx_hal_conf.h HAL configuration file
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- ADC/ADC_AnalogWatchdog/Inc/stm32f1xx_it.h HAL interrupt handlers header file
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- ADC/ADC_AnalogWatchdog/Inc/main.h Header for main.c module
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- ADC/ADC_AnalogWatchdog/Src/stm32f1xx_it.c HAL interrupt handlers
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- ADC/ADC_AnalogWatchdog/Src/main.c Main program
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- ADC/ADC_AnalogWatchdog/Src/stm32f1xx_hal_msp.c HAL MSP file
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- ADC/ADC_AnalogWatchdog/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 STM32F103RB-Nucleo 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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*/
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