PWM Output on STM32F2XX (Solved)

[th2]

Posted on February 02, 2012 at 14:30

Greetings,

I am currently toying around with the KEIL MCBSTM32F200 Evaluation Board(the STM32F207VG uC) and have run into some problems with the PWM output.I want a simple PWM-signal on TIM1, Channel1 (PA8 for STM32F205&207) usingthe standard peripheral library for STM32Fxx.The code below is a mix from the different examples from the standardperipheral library examples for PWM, and I'm sure something critical ismissing.After initializing, all TIM1 registers looks ''ok'' (as far as I can tell, thetimer is a bit too advanced for me...) and the TIM1_CNT register is countingup and resetting.When connecting the oscilloscope to PA8, all I get is a steady 3.3V signal,no PWM.What am I missing here? It's quite frustrating since all other peripheralsI'm using are working fine. Thanks in advance.(code also at

http://pastebin.com/yUmZbXUL

: http://pastebin.com/yUmZbXUL)&sharpinclude ''stm32f2xx.h''&sharpinclude ''stm32f2xx_gpio.h''&sharpinclude ''stm32f2xx_rcc.h''&sharpinclude ''stm32f2xx_tim.h''&sharpinclude ''system_stm32f2xx.h''/****************************************************************************/void main(void) { TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCInitTypeDef TIM_OCInitStructure; GPIO_InitTypeDef GPIO_InitStructure; uint16_t period; uint16_t pulse; /* Initialize clock - defined in system_stm32f2xx.h */ SystemInit(); /* Compute the value for the ARR register to have a period of 20 KHz */ period = (SystemCoreClock / 20000 ) - 1; /* Compute the CCR1 value to generate a PWN signal with 50% duty cycle */ pulse = (uint16_t) (((uint32_t) 5 * (period - 1)) / 10); /* GPIOA clock enable */ RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); /* Initialize PA8, Alternative Function, 100Mhz, Output, Push-pull */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ; GPIO_Init(GPIOA, &GPIO_InitStructure); GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_TIM1); /* TIM1 clock enable */ RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 , ENABLE); /* Timer Base configuration */ TIM_TimeBaseStructInit(&TIM_TimeBaseStructure); TIM_TimeBaseStructure.TIM_Prescaler = 0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseStructure.TIM_Period = period; TIM_TimeBaseStructure.TIM_ClockDivision = 0; TIM_TimeBaseStructure.TIM_RepetitionCounter = 0; TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); /* Channel 1 output configuration */ TIM_OCStructInit(&TIM_OCInitStructure); TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = pulse; TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set; TIM_OC1Init(TIM1, &TIM_OCInitStructure); /* TIM1 counter enable */ TIM_Cmd(TIM1, ENABLE); /* TIM1 Main Output Enable */ TIM_CtrlPWMOutputs(TIM1, ENABLE); /* forever... */ while (1) { __asm(''nop''); }} #stm32f2xx-pwm-tim1

[Tesla DeLorean]

Posted on July 18, 2016 at 17:47

This should work for a F2/F4 part with TIM1_CH1 on PE9

// STM32 PWM (TIM1 CH1 PE.09) STM32F4 Discovery - sourcer32@gmail.com
#include ''stm32f4_discovery.h''
/**************************************************************************************/
void RCC_Configuration(void)
{
/* --------------------------- System Clocks Configuration -----------------*/
/* TIM1 clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
/* GPIOE clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
}
/**************************************************************************************/
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/*-------------------------- GPIO Configuration ----------------------------*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOE, &GPIO_InitStructure);
/* Connect TIM1 pins to AF */
GPIO_PinAFConfig(GPIOE, GPIO_PinSource9, GPIO_AF_TIM1);
}
/**************************************************************************************/
void TIM1_Configuration(void)
{
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
uint16_t Period;
Period = 1000000 / 20000; // 20 KHz for 1MHz prescaled
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Prescaler = (SystemCoreClock / 1000000) - 1; // Get clock to 1 MHz on STM32F2/F4
TIM_TimeBaseStructure.TIM_Period = Period - 1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
/* Enable TIM1 Preload register on ARR */
TIM_ARRPreloadConfig(TIM1, ENABLE);
/* TIM PWM1 Mode configuration */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_Pulse = Period / 2; // 50%
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
/* Output Compare PWM1 Mode configuration: Channel1 PA.08 */
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
/* TIM1 Main Output Enable */
TIM_CtrlPWMOutputs(TIM1, ENABLE);
/* TIM1 enable counter */
TIM_Cmd(TIM1, ENABLE);
}
/**************************************************************************************/
int main(void)
{
RCC_Configuration();
GPIO_Configuration();
TIM1_Configuration();
while(1); // Don't want to exit
}
/**************************************************************************************/
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf(''Wrong parameters value: file %s on line %d

'', file, line) */
/* Infinite loop */
while (1)
{
}
}
#endif
/**************************************************************************************/