mirror of
https://bitbucket.org/librepilot/librepilot.git
synced 2024-12-13 20:48:42 +01:00
f1694527cc
git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@411 ebee16cc-31ac-478f-84a7-5cbb03baadba
234 lines
7.1 KiB
C
234 lines
7.1 KiB
C
/**
|
|
******************************************************************************
|
|
*
|
|
* @file pios_ppm.c
|
|
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
|
|
* @brief PPM Input functions
|
|
* @see The GNU Public License (GPL) Version 3
|
|
* @defgroup PIOS_PPM PPM 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"
|
|
|
|
#if defined(PIOS_INCLUDE_PPM)
|
|
|
|
/* Local Variables */
|
|
|
|
static TIM_ICInitTypeDef TIM_ICInitStructure;
|
|
static uint8_t PulseIndex;
|
|
static uint32_t PreviousValue;
|
|
static uint32_t CurrentValue;
|
|
static uint32_t CapturedValue;
|
|
static uint32_t CaptureValue[PIOS_PPM_NUM_INPUTS];
|
|
|
|
static uint8_t SupervisorState = 0;
|
|
static uint32_t CapCounter[PIOS_PPM_NUM_INPUTS];
|
|
static uint32_t CapCounterPrev[PIOS_PPM_NUM_INPUTS];
|
|
|
|
|
|
/**
|
|
* Initialises all the LED's
|
|
*/
|
|
void PIOS_PPM_Init(void)
|
|
{
|
|
/* Flush counter variables */
|
|
int32_t i;
|
|
|
|
PulseIndex = 0;
|
|
PreviousValue = 0;
|
|
CurrentValue = 0;
|
|
CapturedValue = 0;
|
|
|
|
for(i = 0; i < PIOS_PPM_NUM_INPUTS; i++) {
|
|
CaptureValue[i] = 0;
|
|
}
|
|
|
|
/* Setup RCC */
|
|
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
|
|
|
|
/* Enable timer interrupts */
|
|
NVIC_InitTypeDef NVIC_InitStructure;
|
|
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
|
|
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
|
|
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
|
|
NVIC_InitStructure.NVIC_IRQChannel = PIOS_PPM_TIM_IRQ;
|
|
NVIC_Init(&NVIC_InitStructure);
|
|
|
|
/* Configure input pins */
|
|
GPIO_InitTypeDef GPIO_InitStructure;
|
|
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD;
|
|
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
|
|
GPIO_InitStructure.GPIO_Pin = PIOS_PPM_GPIO_PIN;
|
|
GPIO_Init(PIOS_PPM_GPIO_PORT, &GPIO_InitStructure);
|
|
|
|
/* Configure timer for input capture */
|
|
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
|
|
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
|
|
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
|
|
TIM_ICInitStructure.TIM_ICFilter = 0x0;
|
|
TIM_ICInitStructure.TIM_Channel = PIOS_PPM_TIM_CHANNEL;
|
|
TIM_ICInit(PIOS_PPM_TIM_PORT, &TIM_ICInitStructure);
|
|
|
|
/* Configure timer clocks */
|
|
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
|
|
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
|
|
TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
|
|
TIM_TimeBaseStructure.TIM_Prescaler = (PIOS_MASTER_CLOCK / 1000000) - 1;
|
|
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
|
|
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
|
|
TIM_InternalClockConfig(PIOS_PPM_TIM_PORT);
|
|
TIM_TimeBaseInit(PIOS_PPM_TIM_PORT, &TIM_TimeBaseStructure);
|
|
|
|
/* Enable the Capture Compare Interrupt Request */
|
|
TIM_ITConfig(PIOS_PPM_TIM_PORT, PIOS_PPM_TIM_CCR, ENABLE);
|
|
|
|
/* Enable timers */
|
|
TIM_Cmd(PIOS_PPM_TIM, ENABLE);
|
|
|
|
/* Supervisor Setup */
|
|
#if (PIOS_PPM_SUPV_ENABLED)
|
|
/* Flush counter variables */
|
|
for(i = 0; i < PIOS_PPM_NUM_INPUTS; i++) {
|
|
CapCounter[i] = 0;
|
|
}
|
|
for(i = 0; i < PIOS_PPM_NUM_INPUTS; i++) {
|
|
CapCounterPrev[i] = 0;
|
|
}
|
|
|
|
/* Enable timer clock */
|
|
PIOS_PPM_SUPV_TIMER_RCC_FUNC;
|
|
|
|
/* Configure interrupts */
|
|
NVIC_InitStructure.NVIC_IRQChannel = PIOS_PPM_SUPV_IRQ_CHANNEL;
|
|
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
|
|
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
|
|
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
|
|
NVIC_Init(&NVIC_InitStructure);
|
|
|
|
/* Time base configuration */
|
|
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
|
|
TIM_TimeBaseStructure.TIM_Period = ((1000000 / PIOS_PPM_SUPV_HZ) - 1);
|
|
TIM_TimeBaseStructure.TIM_Prescaler = (PIOS_MASTER_CLOCK / 1000000) - 1; /* For 1 uS accuracy */
|
|
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
|
|
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
|
|
TIM_TimeBaseInit(PIOS_PPM_SUPV_TIMER, &TIM_TimeBaseStructure);
|
|
|
|
/* Enable the CC2 Interrupt Request */
|
|
TIM_ITConfig(PIOS_PPM_SUPV_TIMER, TIM_IT_Update, ENABLE);
|
|
|
|
/* Clear update pending flag */
|
|
TIM_ClearFlag(TIM2, TIM_FLAG_Update);
|
|
|
|
/* Enable counter */
|
|
TIM_Cmd(PIOS_PPM_SUPV_TIMER, ENABLE);
|
|
#endif
|
|
|
|
/* Setup local variable which stays in this scope */
|
|
/* Doing this here and using a local variable saves doing it in the ISR */
|
|
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
|
|
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
|
|
TIM_ICInitStructure.TIM_ICFilter = 0x0;
|
|
}
|
|
|
|
/**
|
|
* Get the value of an input channel
|
|
* \param[in] Channel Number of the channel desired
|
|
* \output -1 Channel not available
|
|
* \output >0 Channel value
|
|
*/
|
|
int32_t PIOS_PPM_Get(int8_t Channel)
|
|
{
|
|
/* Return error if channel not available */
|
|
if(Channel >= PIOS_PPM_NUM_INPUTS) {
|
|
return -1;
|
|
}
|
|
return CaptureValue[Channel];
|
|
}
|
|
|
|
/**
|
|
* Handle TIM1 global interrupt request
|
|
* Some work and testing still needed, need to detect start of frame and decode pulses
|
|
*
|
|
*/
|
|
void TIM1_CC_IRQHandler(void)
|
|
{
|
|
/* Do this as it's more efficient */
|
|
if(TIM_GetITStatus(PIOS_PPM_TIM_PORT, PIOS_PPM_TIM_CCR) == SET) {
|
|
PreviousValue = CurrentValue;
|
|
CurrentValue = TIM_GetCapture2(PIOS_PPM_TIM_PORT);
|
|
}
|
|
|
|
/* Clear TIM3 Capture compare interrupt pending bit */
|
|
TIM_ClearITPendingBit(PIOS_PPM_TIM_PORT, PIOS_PPM_TIM_CCR);
|
|
|
|
/* Capture computation */
|
|
if (CurrentValue > PreviousValue) {
|
|
CapturedValue = (CurrentValue - PreviousValue);
|
|
} else {
|
|
CapturedValue = ((0xFFFF - PreviousValue) + CurrentValue);
|
|
}
|
|
|
|
/* sync pulse */
|
|
if(CapturedValue > 8000) {
|
|
PulseIndex = 0;
|
|
/* trying to detect bad pulses, not sure this is working correctly yet. I need a scope :P */
|
|
} else if(CapturedValue > 750 && CapturedValue < 2500) {
|
|
if(PulseIndex < PIOS_PPM_NUM_INPUTS) {
|
|
CaptureValue[PulseIndex] = CapturedValue;
|
|
CapCounter[PulseIndex]++;
|
|
PulseIndex++;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This function handles TIM3 global interrupt request.
|
|
*/
|
|
PIOS_PPM_SUPV_IRQ_FUNC
|
|
{
|
|
/* Clear timer interrupt pending bit */
|
|
TIM_ClearITPendingBit(PIOS_PPM_SUPV_TIMER, TIM_IT_Update);
|
|
|
|
/* Simple state machine */
|
|
if(SupervisorState == 0) {
|
|
/* Save this states values */
|
|
for(int32_t i = 0; i < PIOS_PPM_NUM_INPUTS; i++) {
|
|
CapCounterPrev[i] = CapCounter[i];
|
|
}
|
|
|
|
/* Move to next state */
|
|
SupervisorState = 1;
|
|
} else {
|
|
/* See what channels have been updated */
|
|
for(int32_t i = 0; i < PIOS_PPM_NUM_INPUTS; i++) {
|
|
if(CapCounter[i] == CapCounterPrev[i]) {
|
|
CaptureValue[i] = 0;
|
|
}
|
|
}
|
|
|
|
/* Move to next state */
|
|
SupervisorState = 0;
|
|
}
|
|
}
|
|
|
|
#endif
|