2015-07-15 07:12 AM
Hi
I have adapted the program found below from the example 7PWM_Output in the StdPeriph library examples. My aim is to create 3 PWM channels each with it's respective complimentary output as well as inserted dead time and a 60 degree phase shift between each channel: Channel 1 PWM = 0� Channel 2 PWM = 60� Channel 3 PWM = 120� As the program stands the 3 PWM signals and the complementary signals are correct as well as the dead time. My problem is that I cannot figure out how to insert the phase shifts. I am also having trouble identifying the current clock speed. I am using the STM32F103RBT6 Nucleo board with the Cortex M4 @72MHz Code: &sharpinclude ''stm32f10x.h'' TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCInitTypeDef TIM_OCInitStructure; TIM_BDTRInitTypeDef TIM_BDTRInitStructure; uint16_t TimerPeriod = 0; uint16_t Channel1Pulse = 0, Channel2Pulse = 0, Channel3Pulse = 0; void RCC_Configuration(void); void GPIO_Configuration(void); int main(void) { /* System Clocks Configuration */ RCC_Configuration(); /* GPIO Configuration */ GPIO_Configuration(); /* TIM1 Configuration --------------------------------------------------- */ /* Compute the value to be set in ARR regiter to generate signal frequency at 10 Khz */ TimerPeriod = (SystemCoreClock / 90000 ) - 1; /* Compute CCR1 value to generate a duty cycle at 50% for channel 1 and 1N */ Channel1Pulse = (uint16_t) (((uint32_t) 5 * (TimerPeriod - 1)) / 10); /* Compute CCR2 value to generate a duty cycle at 50% for channel 2 and 2N */ Channel2Pulse = (uint16_t) (((uint32_t) 5 * (TimerPeriod - 1)) / 10); /* Compute CCR3 value to generate a duty cycle at 50% for channel 3 and 3N */ Channel3Pulse = (uint16_t) (((uint32_t) 5 * (TimerPeriod - 1)) / 10); /* Time Base configuration */ TIM_TimeBaseStructure.TIM_Prescaler = 0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseStructure.TIM_Period = TimerPeriod; TIM_TimeBaseStructure.TIM_ClockDivision = 0; TIM_TimeBaseStructure.TIM_RepetitionCounter = 0; TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); /* Channel 1, 2,3 and 4 Configuration in PWM mode */ TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable; TIM_OCInitStructure.TIM_Pulse = Channel1Pulse; TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High; TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set; TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset; TIM_OC1Init(TIM1, &TIM_OCInitStructure); TIM_OCInitStructure.TIM_Pulse = Channel2Pulse; TIM_OC2Init(TIM1, &TIM_OCInitStructure); TIM_OCInitStructure.TIM_Pulse = Channel3Pulse; TIM_OC3Init(TIM1, &TIM_OCInitStructure); /* Dead time configuration (3.7 us) */ TIM_BDTRInitStructure.TIM_DeadTime = 30; TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure); /* TIM1 counter enable */ TIM_Cmd(TIM1, ENABLE); /* TIM1 Main Output Enable */ TIM_CtrlPWMOutputs(TIM1, ENABLE); while (1) { } } void RCC_Configuration(void) { /* TIM1, GPIOA, GPIOB and AFIO clocks enable */ RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE); } /* Configure the TIM1 Pins. */ void GPIO_Configuration(void) { GPIO_InitTypeDef GPIO_InitStructure; /* GPIOA Configuration: Channel 1, 2 and 3 as alternate function push-pull */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOA, &GPIO_InitStructure); /* GPIOB Configuration: Channel 1N, 2N and 3N as alternate function push-pull */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15; GPIO_Init(GPIOB, &GPIO_InitStructure); } Any help will be appreciated. Thank you! #stm32-nucleo