82 lines
3.3 KiB
Plaintext
82 lines
3.3 KiB
Plaintext
/**
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@page TIM_InputCapture TIM example
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@verbatim
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******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
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* @file Examples_LL/TIM/TIM_InputCapture/readme.txt
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* @author MCD Application Team
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* @brief Description of the TIM_InputCapture 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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Use of the TIM peripheral to measure a periodic signal frequency
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provided either by an external signal generator or by
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another timer instance. This example is based on the STM32F1xx TIM
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LL API. The peripheral initialization uses LL unitary service functions
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for optimization purposes (performance and size).
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TIM3_CH1 is configured in input capture mode. The TIM3CLK frequency is set to
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its maximum value (Prescaler is 1) in order to get the best possible resolution.
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So the TIM3 counter clock is SystemCoreClock.
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SystemCoreClock is set to 72 MHz for STM32F1xx Devices.
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The "uwMeasuredFrequency" variable contains the measured signal frequency.
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It is calculated within the capture/compare 1 interrupt service routine.
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The minimum frequency value to measure is TIM3 counter clock / TIMx_CCR1 MAX
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= 72 MHz / 65535
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Due to TIM3_IRQHandler processing time (around 3.50us), the maximum
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frequency value to measure is around 300 kHz.
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TIM2_CH1 is configured to generate a PWM signal. User push-button can be used to
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change the frequency of this signal from 2 kHz up to 20 kHz by steps of 2 kHz.
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It is then possible to run this example without a signal generator by connecting
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TIM2_CH1 to TIM3_CH1.
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@par Directory contents
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- TIM/TIM_InputCapture/Inc/stm32f1xx_it.h Interrupt handlers header file
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- TIM/TIM_InputCapture/Inc/main.h Header for main.c module
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- TIM/TIM_InputCapture/Inc/stm32_assert.h Template file to include assert_failed function
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- TIM/TIM_InputCapture/Src/stm32f1xx_it.c Interrupt handlers
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- TIM/TIM_InputCapture/Src/main.c Main program
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- TIM/TIM_InputCapture/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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- STM32F103RB-Nucleo Set-up
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- When no signal generator is used TIM2_CH1 can be connected to TIM3_CH1:
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- TIM3_CH1 PA.06: connected to pin 5 of CN5 connector
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- TIM2_CH1 PA.00: connected to pin 1 of CN8 connector
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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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