Posted on September 18, 2013 at 02:26
// STM32F4-Discovery TIM4 Triphase Output PD.12, PD.13 and PD.14 - sourcer32@gmail.com
#include ''stm32f4xx.h''
//******************************************************************************
void RCC_Configuration(void)
{
/* enable peripheral clock for TIM4 */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
/* GPIOD clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
}
//******************************************************************************
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* GPIOD Configuration: TIM4 on PD12/PD13/PD14 LED */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOD, &GPIO_InitStructure);
/* Connect TIM4 pin */
GPIO_PinAFConfig(GPIOD, GPIO_PinSource12, GPIO_AF_TIM4); // PD12 TIM4_CH1 GREEN
GPIO_PinAFConfig(GPIOD, GPIO_PinSource13, GPIO_AF_TIM4); // PD13 TIM4_CH2 ORANGE
GPIO_PinAFConfig(GPIOD, GPIO_PinSource14, GPIO_AF_TIM4); // PD13 TIM4_CH3 RED
}
//******************************************************************************
void TIM4_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
int Prescaler, Period;
Prescaler = ((SystemCoreClock / 2) / 360000); // ~360 KHz timebase, assumes APB1 H/4 TIMCLK4 H/2
Period = 36000; // ~10 Hz -> ~ 5 Hz
// The toggle halves the frequency
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = Period - 1;
TIM_TimeBaseStructure.TIM_Prescaler = Prescaler - 1;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
/* Output Compare Toggle Mode configuration: Channel 1, 2 and 3 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
/* Don't want to set 0 or Period, but have 3 points at 120 degrees from each other */
TIM_OCInitStructure.TIM_Pulse = ((Period * 1) / 3) - 1;
TIM_OC1Init(TIM4, &TIM_OCInitStructure);
TIM_OCInitStructure.TIM_Pulse = ((Period * 2) / 3) - 1;
TIM_OC2Init(TIM4, &TIM_OCInitStructure);
TIM_OCInitStructure.TIM_Pulse = ((Period * 3) / 3) - 1;
TIM_OC3Init(TIM4, &TIM_OCInitStructure);
/* TIM4 enable counter */
TIM_Cmd(TIM4, ENABLE);
}
//******************************************************************************
int main(void)
{
RCC_Configuration();
GPIO_Configuration();
TIM4_Configuration();
while(1); /* Infinite loop */
}
