/** ****************************************************************************** * * @file pios_pwm.c * @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2009. * @brief PWM Input functions * @see The GNU Public License (GPL) Version 3 * @defgroup PIOS_PWM PWM Input Functions * @{ * *****************************************************************************/ /* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* Project Includes */ #include "pios.h" /* Local Variables */ volatile uint16_t IC3Value = 0; volatile uint16_t DutyCycle = 0; volatile uint32_t Frequency = 0; /** * Initialises all the LED's */ void PIOS_PWM_Init(void) { /* Setup RCC */ RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); /* Enable the TIM3 global Interrupt */ NVIC_InitTypeDef NVIC_InitStructure; NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); /* TIM3 channel 2 pin (PA.01) configuration */ GPIO_InitTypeDef GPIO_InitStructure; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//GPIO_Mode_AF_OD GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz; GPIO_InitStructure.GPIO_Pin = RECEIVER1_PIN; GPIO_Init(RECEIVER1_GPIO_PORT, &GPIO_InitStructure); /* TIM3 configuration: PWM Input mode ------------------------ The Rising edge is used as active edge, The TIM3 CCR2 is used to compute the frequency value The TIM3 CCR1 is used to compute the duty cycle value ------------------------------------------------------------ */ TIM_ICInitTypeDef TIM_ICInitStructure; 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 = 0x0; TIM_ICInitStructure.TIM_Channel = RECEIVER1_CH; TIM_PWMIConfig(TIM3, &TIM_ICInitStructure); /* Select the TIM3 Input Trigger: TI2FP2 */ TIM_SelectInputTrigger(TIM3, TIM_TS_TI2FP2); /* Select the slave Mode: Reset Mode */ TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Reset); /* Enable the Master/Slave Mode */ TIM_SelectMasterSlaveMode(TIM3, TIM_MasterSlaveMode_Enable); /* TIM enable counter */ TIM_Cmd(TIM3, ENABLE); /* Enable the CC3 Interrupt Request */ TIM_ITConfig(TIM3, TIM_IT_CC3, ENABLE); } /** * This function handles TIM3 global interrupt request. */ void TIM3_IRQHandler(void) { /* Clear TIM3 Capture compare interrupt pending bit */ TIM_ClearITPendingBit(TIM3, TIM_IT_CC3); /* Get the Input Capture value */ IC3Value = TIM_GetCapture3(TIM3); // if (IC3Value != 0) // { // /* Duty cycle computation */ // DutyCycle = (TIM_GetCapture1(TIM3) * 100) / IC3Value; // // /* Frequency computation */ // Frequency = 72000000 / IC3Value; // } else { // DutyCycle = 0; // Frequency = 0; // } }