Added timer.c and timer.h

.gitignore

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+electron-rom-emulator.bin
+electron-rom-emulator.elf
+electron-rom-emulator.hex
+/master_buildss

timer.c

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+#include "timer.h"
+
+void setupOnePulse(void)
+{
+
+  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
+  TIM_ICInitTypeDef       TIM_ICInitStructure;
+  TIM_OCInitTypeDef       TIM_OCInitStructure;
+
+  /* TIM Configuration */
+  TIM_Config();
+
+
+  /* Time base configuration */
+  TIM_TimeBaseStructure.TIM_Period = 27;    // ARR
+  TIM_TimeBaseStructure.TIM_Prescaler = 0;
+  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
+  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
+
+  TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
+
+
+  /* TIM4 PWM2 Mode configuration: Channel1 */
+  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
+  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
+  // 50 = 450ns between trigger and start of one pulse @240MHz
+  // 40 = 370ns between trigger and start of one pulse @240MHz
+  // 30 = 290ns between trigger and start of one pulse @240MHz
+  // 20 = 210ns between trigger and start of one pulse @240MHz
+  // so about 9ns per step
+  TIM_OCInitStructure.TIM_Pulse = 18;        // CCR1
+  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
+
+  TIM_OC1Init(TIM4, &TIM_OCInitStructure);
+
+  /* TIM4 configuration in Input Capture Mode */
+
+  TIM_ICStructInit(&TIM_ICInitStructure);
+
+  TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
+  TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling;
+  TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
+  TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
+  TIM_ICInitStructure.TIM_ICFilter = 0;
+
+  TIM_ICInit(TIM4, &TIM_ICInitStructure);
+
+  /* One Pulse Mode selection */
+  TIM_SelectOnePulseMode(TIM4, TIM_OPMode_Single);
+
+  /* Input Trigger selection */
+  TIM_SelectInputTrigger(TIM4, TIM_TS_TI2FP2);
+
+  /* Slave Mode selection: Trigger Mode */
+  TIM_SelectSlaveMode(TIM4, TIM_SlaveMode_Trigger);
+
+}
+
+/**
+  * @brief  Configure the TIM4 Pins.
+  * @param  None
+  * @retval None
+  */
+void TIM_Config(void)
+{
+  GPIO_InitTypeDef GPIO_InitStructure;
+
+  /* TIM4 clock enable */
+  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
+
+  /* GPIOB clock enable */
+  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
+
+  /* TIM4_CH1 pin (PB.06) configuration */
+  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
+  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_NOPULL;
+  GPIO_Init(GPIOB, &GPIO_InitStructure);
+
+  /* TIM4_CH2 pin (PB.07) configuration */
+  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
+  GPIO_Init(GPIOB, &GPIO_InitStructure);
+
+  /* Connect TIM pins to AF2 */
+  GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_TIM4);
+  GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_TIM4); 
+
+}

timer.h

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+#ifndef __TIMER_H
+#define __TIMER_H
+#include <stdint.h>
+#include "stm32f4xx.h"
+
+
+void setupOnePulse(void);
+void TIM_Config(void);
+
+
+#endif