109 lines
5.1 KiB
Plaintext
109 lines
5.1 KiB
Plaintext
/**
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@page ADC_MultimodeDualInterleaved ADC example
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@verbatim
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******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
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* @file Examples_LL/ADC/ADC_MultimodeDualInterleaved/readme.txt
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* @author MCD Application Team
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* @brief Description of the ADC_MultimodeDualInterleaved 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 several ADC peripherals in multimode and interleaved mode.
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This example is based on the STM32F1xx ADC LL API.
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The peripheral initialization is done using LL unitary service functions
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for optimization purposes (performance and size).
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Description of multimode interleaved:
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ADC master instance synchronizes and manages ADC slave instance.
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Multimode interleaved combines ADC instances to convert
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the same channel and increase the overall ADC conversion rate.
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This example configures the ADC to perform conversions at the
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maximum ADC conversion rate possible (with a sampling time
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corresponding to ADC resolution 12 bits).
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Example configuration:
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ADC1 and ADC2 instances (master and slave) are configured in continuous conversion mode,
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from SW trigger (in order to reach more simply the maximum conversion rate possible,
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but trigger from timer is also possible).
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Both ADC instances are configured to convert a single channel (1 channel from a GPIO),
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this channel is common to ADC1 and ADC2.
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DMA is configured to transfer conversion data in an array, in circular mode.
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Note: One DMA channel is used (the one of ADC master) to transfer data from
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both ADC instances (master and slave).
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Usage of two DMA channels (one for ADC master, one for ADC slave) is also
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possible: this is the recommended configuration in case of high ADC
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conversions rates and applications using other DMA channels intensively.
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Example execution:
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From the first press on push button, the ADC converts the selected channel
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continuously.
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DMA transfers conversion data to the array, transfer complete interruption occurs.
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Results array is updated indefinitely (DMA in circular mode).
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LED2 is turned on when the DMA transfer is completed (results array full)
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and turned off at next DMA half-transfer (result array first half updated).
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Note: ADC is converting at high frequency, therefore LED2 is toggling at high frequency
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and will appear as dimming.
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Use an oscilloscope probe on LED2 to watch DMA transfers frequency.
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Note: A file is provide with this example to detail the ADC conversions timings.
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Refer to file "ADC MultimodeDualInterleaved timing simulation STM32F1.xls".
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For debug: variables to monitor with debugger watch window:
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- "aADCxADCyMultimodeDualConvertedData[ADC_CONVERTED_DATA_BUFFER_SIZE]": ADC multimode dual conversion data: ADC master and ADC slave conversion data are concatenated in a registers of 32 bits.
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- "aADCxMultimodeDualMasterConvertedData[ADC_CONVERTED_DATA_BUFFER_SIZE]": For the purpose of this example, dispatch multimode dual conversion data into array corresponding to ADC master conversion data.
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- "aADCyMultimodeDualSlaveConvertedData[ADC_CONVERTED_DATA_BUFFER_SIZE]": For the purpose of this example, dispatch multimode dual conversion data into array corresponding to ADC slave conversion data.
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- "ubDmaTransferStatus": status of DMA transfer of ADC group regular conversions
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Connection needed:
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Use an external power supply, adjust supply voltage and connect it to analog input pin (cf pin below).
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Other peripherals used:
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1 GPIO for push button
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1 GPIO for LED2
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1 GPIO for analog input: PA.04 (Arduino connector CN8 pin A2, Morpho connector CN7 pin 32)
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DMA
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@par Directory contents
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- ADC/ADC_MultimodeDualInterleaved/Inc/stm32f1xx_it.h Interrupt handlers header file
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- ADC/ADC_MultimodeDualInterleaved/Inc/main.h Header for main.c module
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- ADC/ADC_MultimodeDualInterleaved/Inc/stm32_assert.h Template file to include assert_failed function
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- ADC/ADC_MultimodeDualInterleaved/Src/stm32f1xx_it.c Interrupt handlers
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- ADC/ADC_MultimodeDualInterleaved/Src/main.c Main program
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- ADC/ADC_MultimodeDualInterleaved/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 STM32F103xB 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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* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
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*/
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