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/** @page TIM_PWMOutput TIM PWM Output example @verbatim ******************** (C) COPYRIGHT 2016 STMicroelectronics ******************* * @file TIM/TIM_PWMOutput/readme.txt * @author MCD Application Team * @brief Description of the PWM signals generation using TIM1 ****************************************************************************** * @attention * * <h2><center>© Copyright (c) 2016 STMicroelectronics. * All rights reserved.</center></h2> * * 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 Configuration of the TIM peripheral in PWM (pulse width modulation) mode. SystemCoreClock is set to 48 MHz for STM32F0xx Devices. In this example TIM1 input clock (TIM1CLK) is set to APB1 clock (PCLK1), since APB1 prescaler is equal to 1. TIM1CLK = PCLK1 PCLK1 = HCLK => TIM1CLK = HCLK = SystemCoreClock To get TIM1 counter clock at 16 MHz, the prescaler is computed as follows: Prescaler = (TIM1CLK / TIM1 counter clock) - 1 Prescaler = ((SystemCoreClock) /16 MHz) - 1 To get TIM1 output clock at 24 KHz, the period (ARR)) is computed as follows: ARR = (TIM1 counter clock / TIM1 output clock) - 1 = 665 TIM1 Channel1 duty cycle = (TIM1_CCR1/ TIM1_ARR + 1)* 100 = 50% TIM1 Channel2 duty cycle = (TIM1_CCR2/ TIM1_ARR + 1)* 100 = 37.5% TIM1 Channel3 duty cycle = (TIM1_CCR3/ TIM1_ARR + 1)* 100 = 25% TIM1 Channel4 duty cycle = (TIM1_CCR4/ TIM1_ARR + 1)* 100 = 12.5% The PWM waveforms can be displayed using an oscilloscope. @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 need to ensure that the SysTick time base is always set to 1 millisecond to have correct HAL operation. @par Directory contents - TIM/TIM_PWMOutput/Inc/stm32f0xx_hal_conf.h HAL configuration file - TIM/TIM_PWMOutput/Inc/stm32f0xx_it.h Interrupt handlers header file - TIM/TIM_PWMOutput/Inc/main.h Header for main.c module - TIM/TIM_PWMOutput/Src/stm32f0xx_it.c Interrupt handlers - TIM/TIM_PWMOutput/Src/main.c Main program - TIM/TIM_PWMOutput/Src/stm32f0xx_hal_msp.c HAL MSP file - TIM/TIM_PWMOutput/Src/system_stm32f0xx.c STM32F0xx system source file @par Hardware and Software environment - This example runs on STM32F0xx devices. - In this example, the clock is set to 48 MHz. - This example has been tested with STMicroelectronics STM32072B-EVAL RevB board and can be easily tailored to any other supported device and development board. - STM32072B-EVAL RevB Set-up Connect the following pins to an oscilloscope to monitor the different waveforms: - TIM1_CH1 : PA.08 (pin 8 in CN7 connector) - TIM1_CH2 : PA.09 (pin 7 in CN7 connector) - TIM1_CH3 : PA.10 (pin 9 in CN7 connector) - TIM1_CH4 : PA.11 (pin 12 in CN7 connector) @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> */