mirror of
https://github.com/STMicroelectronics/STM32CubeF7.git
synced 2025-05-07 19:29:17 +08:00
89 lines
4.3 KiB
Plaintext
89 lines
4.3 KiB
Plaintext
/**
|
||
@page ADC_RegularConversion_Polling conversion using Polling
|
||
|
||
@verbatim
|
||
******************************************************************************
|
||
* @file ADC/ADC_RegularConversion_Polling/readme.txt
|
||
* @author MCD Application Team
|
||
* @brief Description of the ADC RegularConversion Polling example.
|
||
******************************************************************************
|
||
*
|
||
* Copyright (c) 2016 STMicroelectronics. All rights reserved.
|
||
*
|
||
* This software component is licensed by ST under BSD 3-Clause license,
|
||
* the "License"; You may not use this file except in compliance with the
|
||
* License. You may obtain a copy of the License at:
|
||
* opensource.org/licenses/BSD-3-Clause
|
||
*
|
||
******************************************************************************
|
||
@endverbatim
|
||
|
||
@par Example Description
|
||
|
||
How to use the ADC in Polling mode to convert data through the HAL API.
|
||
|
||
When the end of conversion occurs, the converted data of ADC3 DR register is
|
||
affected to the uhADCxConvertedValue variable.
|
||
|
||
In this example, the system clock is 216MHz, APB2 = 108MHz and ADC clock = APB2/4.
|
||
Since ADC3 clock is 27 MHz and sampling time is set to 3 cycles, the conversion
|
||
time to 12bit data is 12 cycles so the total conversion time is (12+3)/27= 0.55us (1.8Msps).
|
||
|
||
User can vary the ADC_CHANNEL_8 voltage using the Eval Board potentiometer (RV1) connected to PF.10.
|
||
The converted value is monitored through debugger: uhADCxConvertedValue variable.
|
||
|
||
The uhADCxConvertedValue read value is coded on 12 bits, the Vref+ reference voltage is connected
|
||
on the board to VDD (+3.3V), the Vref- reference voltage is connected on the board to the ground.
|
||
To convert the read value in volts, here is the equation to apply :
|
||
Voltage = uhADCxConvertedValue * (Vref+ - Vref-) / (2^12) = uhADCxConvertedValue * 3.3 / 4096
|
||
|
||
STM32 Eval board's LEDs can be used to monitor the transfer status:
|
||
- LED3 is ON when there are an error in initialization.
|
||
|
||
@par Keywords
|
||
|
||
Analog, ADC, Analog to Digital Converter, Regular Conversion, Polling, Single Conversion
|
||
|
||
@Note<74>If the user code size exceeds the DTCM-RAM size or starts from internal cacheable memories (SRAM1 and SRAM2),that is shared between several processors,
|
||
<20><><EFBFBD><EFBFBD><EFBFBD>then it is highly recommended to enable the CPU cache and maintain its coherence at application level.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>The address and the size of cacheable buffers (shared between CPU and other masters) must be properly updated to be aligned to cache line size (32 bytes).
|
||
|
||
@Note It is recommended to enable the cache and maintain its coherence, but depending on the use case
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> It is also possible to configure the MPU as "Write through", to guarantee the write access coherence.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>In that case, the MPU must be configured as Cacheable/Bufferable/Not Shareable.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Even though the user must manage the cache coherence for read accesses.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Please refer to the AN4838 <20>Managing memory protection unit (MPU) in STM32 MCUs<55>
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Please refer to the AN4839 <20>Level 1 cache on STM32F7 Series<65>
|
||
|
||
@par Directory contents
|
||
|
||
- ADC/ADC_RegularConversion_Polling/Inc/stm32f7xx_hal_conf.h HAL configuration file
|
||
- ADC/ADC_RegularConversion_Polling/Inc/stm32f7xx_it.h DMA interrupt handlers header file
|
||
- ADC/ADC_RegularConversion_Polling/Inc/main.h Header for main.c module
|
||
- ADC/ADC_RegularConversion_Polling/Src/stm32f7xx_it.c DMA interrupt handlers
|
||
- ADC/ADC_RegularConversion_Polling/Src/main.c Main program
|
||
- ADC/ADC_RegularConversion_Polling/Src/stm32f7xx_hal_msp.c HAL MSP file
|
||
- ADC/ADC_RegularConversion_Polling/Src/system_stm32f7xx.c STM32F7xx system source file
|
||
|
||
@par Hardware and Software environment
|
||
|
||
- This example runs on STM32F756xx/STM32F746xx devices.
|
||
|
||
- This example has been tested with STM327x6G-EVAL board revB and can be
|
||
easily tailored to any other supported device and development board.
|
||
|
||
- STM327x6G-EVAL revB Set-up
|
||
- Use the Potentiometer (RV1) of the Eval board (connected to PF.10).
|
||
- JP24 must be fitted in 1-2 positions
|
||
- JP23 must be fitted in 2-3 positions
|
||
|
||
@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
|
||
|
||
* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
|
||
*/
|