How to Trigger TIM2 via TIM3?

[ferhatyol-23]

Hi.

I'm reading Incremental Optic encoder with Timer3. The counter value is 4095 when the encoder rotates one turn. My goal is to produce pulses from 0-25ms through another timer when the Encoder turns half a turn.

In order to do this, I am trying to trigger Timer2 via Timer3. But I couldn't run

This is Encoder Timer Settings

void Encoder_Init(void)
{
  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
	TIM_OCInitTypeDef  TIM_OCInitStructure;
	GPIO_InitTypeDef GPIO_InitStructure;
	
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
 
	// Step 1: Initialize GPIO as input for rotary encoder
	//PA6 (TIM3_CH1) (encoder pin A), PA7 (TIM3_CH2) (encoder pin B)
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	TIM_TimeBaseStructure.TIM_Prescaler = 0;
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up | TIM_CounterMode_Down;
	TIM_TimeBaseStructure.TIM_Period = 4095;
	TIM_TimeBaseStructure.TIM_ClockDivision = 0;
	TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
	
  /* Output Compare Active Mode configuration: Channel1 */
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 1000;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OC1Init(TIM3, &TIM_OCInitStructure);
	
	TIM_SetCounter(TIM3,0);
 
	TIM_EncoderInterfaceConfig(TIM3, TIM_EncoderMode_TI12, TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);
	
	TIM_SelectOutputTrigger(TIM3,TIM_TRGOSource_OC1Ref);
	
	TIM_Cmd(TIM3, ENABLE);
	
}

Slave Timer settings

void SlaveTimerInit(void)
{
  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
  TIM_OCInitTypeDef  TIM_OCInitStructure;
  GPIO_InitTypeDef GPIO_InitStruct;
	
  // Enable clock
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	
  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0;
  GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOA, &GPIO_InitStruct);
	
	  // Time Base configuration
	TIM_TimeBaseStructure.TIM_Prescaler = 72-1;
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
	TIM_TimeBaseStructure.TIM_ClockDivision = 0;
	TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
	
  /* TIM2 PWM2 Mode configuration: Channel1 */
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 20000;  //20ms
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
 
  TIM_OC1Init(TIM2, &TIM_OCInitStructure);
	
  /* One Pulse Mode selection */
  TIM_SelectOnePulseMode(TIM2, TIM_OPMode_Single);
	
  /* Input Trigger selection */
  TIM_SelectInputTrigger(TIM2, TIM_TS_ITR0);
 
  /* Slave Mode selection: Trigger Mode */
  TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Trigger);
	
}

Where am I making mistakes? Thanks. How to do it?

[Tesla DeLorean]

What part specifically are you using?

What routing does the Reference Manual for your part indicate is available?

[ferhatyol-23]

I looked at the Reference Manual, but I could not figure out what direction to do. First, is this Possible? Could you give me an example?

[henry.dick]

1. look at the datasheet. not all timers can be a slave, or master.
2. see examples here: https://dannyelectronics.wordpress.com/2018/07/04/composite-timers-continued/

you either implement that in spl/hal, or just change the smcr register.