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electronicsbasickid
Associate III
May 17, 2021
Solved

STM32L100RCT6 - timer PWM with boolean variable

  • May 17, 2021
  • 1 reply
  • 606 views

Hello,

I am working with the discovery board STM32L100RC. I am trying to have three different timers (TIM2, TIM3, TIM4) as PWM. I'd like to do it's to have each timer ouput at '1' (3.3v) when a boolean variable is equal to '1' and at '0' (0V) when the same variable is equal to '0' .

Here's what I started to code for each timer :

static void MX_TIM2_Init(void)
{
 
 TIM_ClockConfigTypeDef sClockSourceConfig = {0};
 TIM_MasterConfigTypeDef sMasterConfig = {0};
 TIM_OC_InitTypeDef sConfigOC = {0};
 
 htim2.Instance = TIM2;
 htim2.Init.Prescaler = 1;
 htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
 htim2.Init.Period = 15999;
 htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
 htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
 if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
 {
 Error_Handler();
 }
 sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
 if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_TIM_PWM_Init(&htim2) != HAL_OK)
 {
 Error_Handler();
 }
 sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
 sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
 if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
 {
 Error_Handler();
 }
 sConfigOC.OCMode = TIM_OCMODE_PWM1;
 sConfigOC.Pulse = 0;
 sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
 sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
 if (HAL_TIM_PWM_ConfigChannel(&htim2, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
 {
 Error_Handler();
 }
 
 HAL_TIM_MspPostInit(&htim2);
}

My question is the following one : how can we ask the timer to change its value according to a variable ?

Thank you in advance for you help,

Jay.

This topic has been closed for replies.
Best answer by TDK

There's no way to tie a timer output to a variable so that it changes automatically when the variable changes value. You'll need to change the timer output via enabling/disabling or changing duty cycle manually when the variable changes.

1 reply

TDK
TDKBest answer
Super User
May 17, 2021

There's no way to tie a timer output to a variable so that it changes automatically when the variable changes value. You'll need to change the timer output via enabling/disabling or changing duty cycle manually when the variable changes.

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