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