mirror of
https://bitbucket.org/librepilot/librepilot.git
synced 2024-12-10 18:24:11 +01:00
47038af0c0
git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@283 ebee16cc-31ac-478f-84a7-5cbb03baadba
108 lines
3.0 KiB
C
108 lines
3.0 KiB
C
/**
|
|
******************************************************************************
|
|
*
|
|
* @file pios_delay.c
|
|
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
|
|
* Parts by Thorsten Klose (tk@midibox.org) (tk@midibox.org)
|
|
* @brief Delay Functions
|
|
* - Provides a micro-second granular delay using a TIM
|
|
* @see The GNU Public License (GPL) Version 3
|
|
* @defgroup PIOS_DELAY Delay 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_DELAY)
|
|
|
|
/**
|
|
* Initialises the Timer used by PIOS_DELAY functions<BR>
|
|
* This is called from pios.c as part of the main() function
|
|
* at system start up.
|
|
* \return < 0 if initialisation failed
|
|
*/
|
|
|
|
|
|
int32_t PIOS_DELAY_Init(void)
|
|
{
|
|
/* Enable timer clock */
|
|
PIOS_DELAY_TIMER_RCC_FUNC;
|
|
|
|
/* Time base configuration */
|
|
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
|
|
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
|
|
TIM_TimeBaseStructure.TIM_Period = 65535; // maximum value
|
|
TIM_TimeBaseStructure.TIM_Prescaler = 72-1; // for 1 uS accuracy fixed to 72Mhz
|
|
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
|
|
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
|
|
TIM_TimeBaseInit(PIOS_DELAY_TIMER, &TIM_TimeBaseStructure);
|
|
|
|
/* Enable counter */
|
|
TIM_Cmd(PIOS_DELAY_TIMER, ENABLE);
|
|
|
|
/* No error */
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Waits for a specific number of uS<BR>
|
|
* Example:<BR>
|
|
* \code
|
|
* // Wait for 500 uS
|
|
* PIOS_DELAY_Wait_uS(500);
|
|
* \endcode
|
|
* \param[in] uS delay (1..65535 microseconds)
|
|
* \return < 0 on errors
|
|
*/
|
|
int32_t PIOS_DELAY_WaituS(uint16_t uS)
|
|
{
|
|
uint16_t start = PIOS_DELAY_TIMER->CNT;
|
|
|
|
/* Note that this event works on 16bit counter wrap-arounds */
|
|
while((uint16_t)(PIOS_DELAY_TIMER->CNT - start) <= uS);
|
|
|
|
/* No error */
|
|
return 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* Waits for a specific number of mS<BR>
|
|
* Example:<BR>
|
|
* \code
|
|
* // Wait for 500 mS
|
|
* PIOS_DELAY_Wait_mS(500);
|
|
* \endcode
|
|
* \param[in] mS delay (1..65535 milliseconds)
|
|
* \return < 0 on errors
|
|
*/
|
|
int32_t PIOS_DELAY_WaitmS(uint16_t mS)
|
|
{
|
|
for(int i = 0; i < mS; i++) {
|
|
PIOS_DELAY_WaituS(1000);
|
|
}
|
|
|
|
/* No error */
|
|
return 0;
|
|
}
|
|
|
|
#endif
|