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LibrePilot/flight/pios/inc/pios_dsm_priv.h

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/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_DSM Spektrum/JR DSMx satellite receiver functions
* @brief PIOS interface to bind and read Spektrum/JR DSMx satellite receiver
* @{
*
* @file pios_dsm_priv.h
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2011.
* @brief Spektrum/JR DSMx satellite receiver private structures.
* @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
*/
#ifndef PIOS_DSM_PRIV_H
#define PIOS_DSM_PRIV_H
#include <pios.h>
#include <pios_stm32.h>
#include <pios_usart_priv.h>
/*
* Currently known DSMx (DSM2, DSMJ, DSMX) satellite serial port settings:
* 115200bps serial stream, 8 bits, no parity, 1 stop bit
* size of each frame: 16 bytes
* data resolution: 10 or 11 bits
* number of frames: 1 or 2
* frame period: 11ms or 22ms
*
* Currently known DSMx frame structure:
* 2 bytes - depend on protocol version:
* for DSM2/DSMJ:
* 1 byte - lost frame counter (8 bit)
* 1 byte - data format (for master receiver bound with 3 or 5 pulses),
* or unknown (for slave receiver bound with 4 or 6 pulses,
* some sources call it also the lost frame counter)
* for DSMX:
* 1 byte - unknown data (does not look like lost frame counter)
* 1 byte - unknown data, has been seen only 0xB2 so far
* 14 bytes - up to 7 channels (16 bit word per channel) with encoded channel
* number, channel value, the "2nd frame in a sequence" flag.
* Unused channels have FF FF instead of data bytes.
*
* Data format identification:
* - for DSM2/DSMJ: [0 0 0 R 0 0 N1 N0]
* where
* R is data resolution (0 - 10 bits, 1 - 11 bits),
* N1..N0 is the number of frames required to receive all channel
* data (01 or 10 are known to the moment, which means 1 or 2 frames).
* Three values for the transmitter information byte have been seen
* thus far: 0x01, 0x02, 0x12.
* - for DSMX this byte contains just 0xB2 or 0xA2 value for any resolution.
* It is not known at the moment how to find the exact resolution from the
* DSMX data stream. The frame number (1 or 2) and 10/11 bit resolution were
* found in different data streams. So it is safer at the moment to ask user
* explicitly choose the resolution.
* Also some weird throttle channel (0) behavior was found in some streams
* from DX8 transmitter (all zeroes). Thus DSMX needs special processing.
*
* Channel data are:
* - for 10 bit: [F 0 C3 C2 C1 C0 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0]
* - for 11 bit: [F C3 C2 C1 C0 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0]
* where
* F is normally 0 but set to 1 for the first channel of the 2nd frame,
* C3 to C0 is the channel number, 4 bit, zero-based, in any order,
* Dx..D0 - channel data (10 or 11 bits)
*
* DSM2 protocol bug: in some cases in 2-frame format some bytes of the
* frame can contain invalid values from the previous frame. They usually
* are the last 5 bytes and can be equal to FF or other data from last
* frame. There is no explicit workaround currently known.
*
* Binding: the number of pulses within bind window after power up defines
* if this receiver is a master (provides receiver capabilities info to
* the transmitter to choose data format) or slave (does not respond to
* the transmitter which falls back to the old DSM mode in that case).
* Currently known are 3(4) pulses for low resolution (10 bit) DSM2 mode,
* 5(6) pulses for high resolution (11 bit) DSM2 mode, and also 7(8) and
* 9(10) pulses for DSMX modes. Thus only 3, 5, 7 or 9 pulses should be
* used for stand-alone satellite receiver to be bound correctly as the
* master.
*/
#define DSM_CHANNELS_PER_FRAME 7
#define DSM_FRAME_LENGTH (1 + 1 + DSM_CHANNELS_PER_FRAME * 2)
#define DSM_2ND_FRAME_MASK 0x8000
/* lower this value as needed if your satellite requires less delay to enter binding. */
#define DSM_BIND_MIN_DELAY_US 90000
/*
* Include lost frame counter and provide it as a last channel value
* for debugging. Currently is not used by the receiver layer.
*/
// #define DSM_LOST_FRAME_COUNTER
/* DSM receiver instance configuration */
struct pios_dsm_cfg {
struct stm32_gpio bind;
};
extern const struct pios_rcvr_driver pios_dsm_rcvr_driver;
extern int32_t PIOS_DSM_Init(uint32_t *dsm_id,
const struct pios_dsm_cfg *cfg,
const struct pios_com_driver *driver,
uint32_t lower_id,
uint8_t bind);
#endif /* PIOS_DSM_PRIV_H */
/**
* @}
* @}
*/