1
0
mirror of https://bitbucket.org/librepilot/librepilot.git synced 2024-11-30 08:24:11 +01:00
LibrePilot/flight/PiOS/Common/pios_rfm22b_rcvr.c
2012-12-13 21:07:19 -07:00

100 lines
3.0 KiB
C

/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_RFM22B_RCVR RFM22B Receiver Input Functions
* @brief Code to output the PPM signal from the RFM22B
* @{
*
* @file pios_rfm22b_rcvr.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
* @brief Implements a receiver interface to the RFM22B device
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* 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_RFM22B_RCVR)
#include "pios_rfm22b_priv.h"
/* Provide a RCVR driver */
static int32_t PIOS_RFM22B_RCVR_Get(uint32_t rcvr_id, uint8_t channel);
static void PIOS_RFM22B_RCVR_Supervisor(uint32_t rcvr_id);
const struct pios_rcvr_driver pios_rfm22b_rcvr_driver = {
.read = PIOS_RFM22B_RCVR_Get,
};
int32_t PIOS_RFM22B_RCVR_Init(uint32_t rcvr_id)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rcvr_id;
if (!PIOS_RFM22B_validate(rfm22b_dev))
return -1;
// Initialize
for (uint8_t i = 0; i < PIOS_RFM22B_RCVR_MAX_CHANNELS; ++i)
rfm22b_dev->ppm_channel[i] = PIOS_RCVR_TIMEOUT;
rfm22b_dev->ppm_supv_timer = 0;
// Register the failsafe timer callback.
if (!PIOS_RTC_RegisterTickCallback(PIOS_RFM22B_RCVR_Supervisor, rcvr_id))
PIOS_DEBUG_Assert(0);
return 0;
}
static int32_t PIOS_RFM22B_RCVR_Get(uint32_t rcvr_id, uint8_t channel)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rcvr_id;
if (!PIOS_RFM22B_validate(rfm22b_dev))
return -1;
if (channel >= GCSRECEIVER_CHANNEL_NUMELEM)
/* channel is out of range */
return -1;
return rfm22b_dev->ppm_channel[channel];
}
static void PIOS_RFM22B_RCVR_Supervisor(uint32_t rcvr_id) {
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rcvr_id;
if (!PIOS_RFM22B_validate(rfm22b_dev))
return;
// RTC runs at 625Hz.
if (++(rfm22b_dev->ppm_supv_timer) < (PIOS_RFM22B_RCVR_TIMEOUT_MS * 1000 / 625))
return;
rfm22b_dev->ppm_supv_timer = 0;
// Have we received fresh values since the last update?
if (!rfm22b_dev->ppm_fresh)
for (uint8_t i = 0; i < PIOS_RFM22B_RCVR_MAX_CHANNELS; ++i)
rfm22b_dev->ppm_channel[i] = 0;
rfm22b_dev->ppm_fresh = false;
}
#endif /* PIOS_INCLUDE_GCSRCVR */
/**
* @}
* @}
*/