Posted on July 08, 2017 at 23:04
Attempts to capture external PWM signal with TIM.h library have been unsuccessful. I figured using semihosting to print values to console would be helpful in debugging however the values refuse to change although I know the output is changing. I have reviewed code many times with no luck finding errors. Any guidance would be greatly appreciated. Below I attach printout in semihosting window as well as my source code. Thank you in advance.
Semihosting Console:
Source Code:
&sharpinclude <stm32f10x_rcc.h>
&sharpinclude <stm32f10x_gpio.h>&sharpinclude <stm32f10x_tim.h>void main(void){ uint16_t TIM_Prescaler = 0; uint16_t TIM_Period = 0; int DutyCycle,Frequency,IC2Value; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; GPIO_InitTypeDef GPIO_InitStructure; TIM_ICInitTypeDef TIM_ICInitStructure; /* TIM3/GPIO A clock enable */ RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA ,ENABLE);/* TIM3 chennel2 configuration : PA.07 */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOA, &GPIO_InitStructure);TIM_ICInitStructure.TIM_Channel = TIM_Channel_2 ;
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; TIM_ICInitStructure.TIM_ICFilter = 0;TIM_TimeBaseStructure.TIM_Period = TIM_Period;
TIM_TimeBaseStructure.TIM_Prescaler = TIM_Prescaler; TIM_TimeBaseStructure.TIM_ClockDivision = 0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);TIM_PWMIConfig(TIM3, &TIM_ICInitStructure);
/* Select the TIM3 Input Trigger: TI2FP2 */
TIM_SelectInputTrigger(TIM3, TIM_TS_TI2FP2);/* Select the slave Mode: Reset Mode */
TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Reset); TIM_SelectMasterSlaveMode(TIM3,TIM_MasterSlaveMode_Enable);/* TIM enable counter */
TIM_Cmd(TIM3, ENABLE); TIM_ITConfig(TIM3, TIM_IT_CC2, ENABLE); while (1) { IC2Value = TIM_GetCapture2(TIM3);if (IC2Value != 0)
{ /* Duty cycle computation */ DutyCycle = (TIM_GetCapture1(TIM3) * 100) / IC2Value; Frequency = IC2Value; } else { DutyCycle = 0; Frequency = 0; } printf(''DutyCycle: %d\r\n Frequency: %d\r\n'' +DutyCycle +Frequency);}
}
#coocox #gpio.h #stm32f100rb #input-capture #pwm #tim.h
