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Timers & alternate functions

Question asked by ressel.tim on Jan 7, 2016
Latest reply on Jan 7, 2016 by Clive One
Hi,

Noob here, trying to get life out of some hardware. I got basic I/O working (blink an LED) but now I am trying to get timers and alternate functions to work, with no luck. I am testing on a Nucleo-F410RE just to get my feet wet.
My Code:
#include "stm32f4xx.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_tim.h"
 
void TM_LEDS_Init(void) {
    GPIO_InitTypeDef GPIO_InitStruct;
 
    /* Clock for GPIOD */
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
 
    /* Alternating functions for pins */
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource4, GPIO_AF_TIM4);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_TIM4);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_TIM4);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_TIM4);
 
    /* Set pins */
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_Init(GPIOA, &GPIO_InitStruct);
}
 
void TM_TIMER_Init(void) {
    TIM_TimeBaseInitTypeDef TIM_BaseStruct;
 
    /* Enable clock for TIM4 */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
 
    TIM_BaseStruct.TIM_Prescaler = 0;
    /* Count up */
    TIM_BaseStruct.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_BaseStruct.TIM_Period = 8399; /* 10kHz PWM */
    TIM_BaseStruct.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_BaseStruct.TIM_RepetitionCounter = 0;
    /* Initialize TIM4 */
    TIM_TimeBaseInit(TIM4, &TIM_BaseStruct);
    /* Start count on TIM4 */
    TIM_Cmd(TIM4, ENABLE);
}
 
void TM_PWM_Init(void) {
    TIM_OCInitTypeDef TIM_OCStruct;
 
    TIM_OCStruct.TIM_OCMode = TIM_OCMode_PWM2;
    TIM_OCStruct.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCStruct.TIM_OCPolarity = TIM_OCPolarity_Low;
 
    TIM_OCStruct.TIM_Pulse = 2099; /* 25% duty cycle */
    TIM_OC1Init(TIM4, &TIM_OCStruct);
    TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);
 
    TIM_OCStruct.TIM_Pulse = 4199; /* 50% duty cycle */
    TIM_OC2Init(TIM4, &TIM_OCStruct);
    TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);
 
    TIM_OCStruct.TIM_Pulse = 6299; /* 75% duty cycle */
    TIM_OC3Init(TIM4, &TIM_OCStruct);
    TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);
 
    TIM_OCStruct.TIM_Pulse = 8399; /* 100% duty cycle */
    TIM_OC4Init(TIM4, &TIM_OCStruct);
    TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);
}
 
int main(void) {
    /* Initialize system */
    SystemInit();
    /* Init leds */
    TM_LEDS_Init();
    /* Init timer */
    TM_TIMER_Init();
    /* Init PWM */
    TM_PWM_Init();
 
    while (1) {
 
    }
}
Looking at the debugger I can see the timer value changing, but there no output. I can't verify id the timer output is actually changing, nor can I verify if I have the alternate function set up right.

Help?

--TimR

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