112 lines
4.8 KiB
Plaintext
112 lines
4.8 KiB
Plaintext
/**
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@page ADC_Sequencer ADC conversion example, using related peripherals (GPIO, DMA), voltage input from DAC, user 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_Sequencer/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 with a sequencer to convert several channels.
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The channels converted are, in order, one external channel and two internal
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channels (VrefInt and temperature sensors).
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Moreover, voltage and temperature are then computed.
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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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- DMA peripheral is used to transfer ADC conversions data.
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ADC settings:
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Sequencer is enabled, and set to convert 3 ranks (3 channels) in discontinuous
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mode, one by one at each conversion trig.
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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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- Each address of this array is containing the conversion data of 1 rank of the
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ADC sequencer.
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- When DMA transfer half-buffer and buffer length are reached, callbacks
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HAL_ADC_ConvHalfCpltCallback() and HAL_ADC_ConvCpltCallback() are called.
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- When the ADC sequence is fully completed (3 ADC conversions), the
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voltage and temperature are computed and placed in variables:
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uhADCChannelToDAC_mVolt, uhVrefInt_mVolt, wTemperature_DegreeCelsius.
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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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- The voltage input on ADC channel is provided from potentiometer RV2.
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Turning this potentiometer will make the voltage vary into full range: from 0 to Vdda (3.3V).
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==> Therefore, there is no external connection needed to run this example.
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STM3210E-EVAL RevD board's LEDs are be used to monitor the program execution status:
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- Normal operation: LED1 is turned-on/off in function of ADC conversion
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result.
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- Turned-off if sequencer has not yet converted all ranks
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- Turned-on if sequencer has converted all ranks
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- Error: In case of error, LED3 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_Sequencer/Inc/stm32f1xx_hal_conf.h HAL configuration file
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- ADC/ADC_Sequencer/Inc/stm32f1xx_it.h DMA interrupt handlers header file
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- ADC/ADC_Sequencer/Inc/main.h Header for main.c module
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- ADC/ADC_Sequencer/Src/stm32f1xx_it.c DMA interrupt handlers
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- ADC/ADC_Sequencer/Src/main.c Main program
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- ADC/ADC_Sequencer/Src/stm32f1xx_hal_msp.c HAL MSP file
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- ADC/ADC_Sequencer/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 STM3210E-EVAL RevD 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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