PWM Time shifting signal

[bmwael1]

Posted on January 08, 2013 at 11:55

Hi,

I program a

PW

M sig

nal in PB4 port using TIM3 using this program

int
main (
void
)
{
while
(1)
{
TIM3->CCR1 = 1000 ; 
}
}
/*____________________________TIM3______________________________*/
/* TIM3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
/* GPIOB Clock */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_0 | GPIO_Pin_1;
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(GPIOB, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource4, GPIO_AF_TIM3);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource5, GPIO_AF_TIM3);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource0, GPIO_AF_TIM3);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource1, GPIO_AF_TIM3);
//________________________________________________________________
/*__________________________TIM3____________________________________*/
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 1999;
TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
/* PWM1 Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);
/* PWM1 Mode configuration: Channel2 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);
/* PWM1 Mode configuration: Channel3 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OC3Init(TIM3, &TIM_OCInitStructure);
TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);
/* PWM1 Mode configuration: Channel4 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OC4Init(TIM3, &TIM_OCInitStructure);
TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM3, ENABLE);
/* TIM3 enable counter */
TIM_Cmd(TIM3, ENABLE);
//________________________________________________________________

It gives a PWM with

50% Duty Cycle

I want to shift time of this signal like this

I have already Signal 1 i want to create Signal 2 shifted by period T

Wh

at

parameter have

i to change ?

Thank you

[bmwael1]

Posted on January 09, 2013 at 14:45

/* PWM1 Mode configuration: Channel1 */

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = 0; TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; TIM_OC1Init(TIM3, &TIM_OCInitStructure); TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

I noticed here that the PWM used is PWM1 i changed it to PWM2

I see that the signal change In PWM1 mode it begin with 0 value then 1 ... But in PWM2 mode it begin with 1 value then 0 .... Are there another mode that i can shift the signal with specific time ?

[bmwael1]

Posted on March 19, 2013 at 17:32

Any help please ?

[Tesla DeLorean]

Posted on March 19, 2013 at 17:53

Not sure you can do this with a singular timer. You could presumably use two timers, and adjust the relative phase by changing the value of CNT with respect to each other.