77 lines
3.1 KiB
Plaintext
77 lines
3.1 KiB
Plaintext
/**
|
|
@page LPTIM_PulseCounter LPTIM example
|
|
|
|
@verbatim
|
|
******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
|
|
* @file Examples_LL/LPTIM/LPTIM_PulseCounter/readme.txt
|
|
* @author MCD Application Team
|
|
* @brief Description of the LPTIM_PulseCounter example.
|
|
******************************************************************************
|
|
* @attention
|
|
*
|
|
* Copyright (c) 2017 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
|
|
|
|
This example describes how to use the LPTIM in counter mode to generate a PWM
|
|
output signal and update PWM duty cycle. This example is based on the STM32F4xx
|
|
LPTIM LL API; peripheral initialization is done using LL unitary services functions
|
|
for optimization purpose (performance and size).
|
|
|
|
To reduce power consumption, MCU enters stop mode after starting counting. Each
|
|
time the counter reaches the maximum value (Period/Autoreload), an interruption
|
|
is generated, the MCU is woke up from stop mode and LED2 toggles the last state.
|
|
|
|
In this example Period value is set to 1000, so each time the counter counts
|
|
(1000 + 1) rising edges on LPTIM1_IN1 pin, an interrupt is generated and LED2
|
|
toggles. If the external function generator is set to provide a square waveform at 1Khz,
|
|
the led will toggle each second.
|
|
|
|
In this example the internal clock provided to the LPTIM1 is LSI (32 kHz),
|
|
so the external input is sampled with LSI clock. In order not to miss any event,
|
|
the frequency of the changes on the external Input1 signal should never exceed the
|
|
frequency of the internal clock provided to the LPTIM1 (LSI for the
|
|
present example).
|
|
|
|
@par Keywords
|
|
|
|
Timer, Low Power, Pulse Counter, Stop mode, Interrupt
|
|
|
|
@par Directory contents
|
|
|
|
- LPTIM/LPTIM_PulseCounter/Inc/stm32f4xx_it.h Interrupt handlers header file
|
|
- LPTIM/LPTIM_PulseCounter/Inc/main.h Header for main.c module
|
|
- LPTIM/LPTIM_PulseCounter/Inc/stm32_assert.h Template file to include assert_failed function
|
|
- LPTIM/LPTIM_PulseCounter/Src/stm32f4xx_it.c Interrupt handlers
|
|
- LPTIM/LPTIM_PulseCounter/Src/main.c Main program
|
|
- LPTIM/LPTIM_PulseCounter/Src/system_stm32f4xx.c STM32F4xx system source file
|
|
|
|
|
|
@par Hardware and Software environment
|
|
|
|
- This example runs on STM32F410xx devices.
|
|
|
|
- This example has been tested with NUCLEO-F410RB RevC board and can be
|
|
easily tailored to any other supported device and development board.
|
|
|
|
- Connect a square waveform generator to PC.00 (pin 6 in CN8 connector).
|
|
If the frequency of the signal is 1 kHz, LED2 toggles every second.
|
|
|
|
@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
|
|
|
|
|
|
*/
|