PWM: Complementary signals

On this example we configure two complementary PWM channels ( when one channel is in high polarity the complement is in low ) with dead time insertion. This configuration is really useful to control single phase driver motors in H bridge mode. It is necessary to call HAL_TIMEx_PWMN_Start function to generate the complementary signal.

#include "bsp.h"

TIM_HandleTypeDef TimHandle;    /*TIM control structure*/
TIM_OC_InitTypeDef sConfig;     /*PWM channel structure*/
/*dead time config structure*/
TIM_BreakDeadTimeConfigTypeDef sBrkConfig; 

int main( void )
{
    HAL_Init();  /*Init library*/

    /* Config TIM1 to generate a signal with a 2KHz period*/
    TimHandle.Instance           = TIM1;
    TimHandle.Init.Prescaler     = 10;
    TimHandle.Init.Period        = 800;
    TimHandle.Init.CounterMode   = TIM_COUNTERMODE_UP;
    HAL_TIM_PWM_Init( &TimHandle );

    /* Config PWM channel with high polarity at 50% duty cycle */
    sConfig.OCMode       = TIM_OCMODE_PWM1;
    sConfig.OCPolarity   = TIM_OCPOLARITY_HIGH;
    sConfig.OCNPolarity  = TIM_OCNPOLARITY_HIGH;
    HAL_TIM_PWM_ConfigChannel( &TimHandle, &sConfig, TIM_CHANNEL_1 );

    /* Enable dead times to avoid conflicts when polarity changes */
    sBrkConfig.BreakState       = TIM_BREAK_DISABLE;
    sBrkConfig.DeadTime         = 200;
    HAL_TIMEx_ConfigBreakDeadTime( &TimHandle, &sBrkConfig );

    /* start the complementary signals */
    HAL_TIM_PWM_Start( &TimHandle, TIM_CHANNEL_1 );
    HAL_TIMEx_PWMN_Start( &TimHandle, TIM_CHANNEL_1 );
    
    while (1)
    {
    
    }
}

msps.c

/*function called by HAL_TIM_PWM_Init to configure the slected pins as PWM outputs*/
void HAL_TIM_PWM_MspInit( TIM_HandleTypeDef *htim )
{
    GPIO_InitTypeDef   GPIO_InitStruct;

    __TIM1_CLK_ENABLE();  /*eneable clock in TIM1*/
    __GPIOA_CLK_ENABLE(); /*eneable clock on port A*/

    /* pin A7 like TIM1_CH1N, A8 like TIM1_CH1 */
    GPIO_InitStruct.Pin = GPIO_PIN_7 | GPIO_PIN_8; 
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF1_TIM1;
    HAL_GPIO_Init( GPIOA, &GPIO_InitStruct );
}