ardupilot/libraries/GCS_MAVLink/GCS_MAVLink.cpp

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2013-05-29 20:50:57 -03:00
// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
/*
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, see <http://www.gnu.org/licenses/>.
*/
/// @file GCS_MAVLink.cpp
/*
This provides some support code and variables for MAVLink enabled sketches
*/
#include <AP_HAL.h>
#include <AP_Common.h>
#include <GCS_MAVLink.h>
#include <GCS.h>
#include <AP_GPS.h>
#ifdef MAVLINK_SEPARATE_HELPERS
#include "include/mavlink/v1.0/mavlink_helpers.h"
#endif
AP_HAL::BetterStream *mavlink_comm_0_port;
AP_HAL::BetterStream *mavlink_comm_1_port;
#if MAVLINK_COMM_NUM_BUFFERS > 2
AP_HAL::BetterStream *mavlink_comm_2_port;
#endif
mavlink_system_t mavlink_system = {7,1,0,0};
// mask of serial ports disabled to allow for SERIAL_CONTROL
static uint8_t mavlink_locked_mask;
/*
lock a channel, preventing use by MAVLink
*/
void GCS_MAVLINK::lock_channel(mavlink_channel_t _chan, bool lock)
{
if (_chan >= MAVLINK_COMM_NUM_BUFFERS) {
return;
}
if (lock) {
mavlink_locked_mask |= (1U<<(unsigned)_chan);
} else {
mavlink_locked_mask &= ~(1U<<(unsigned)_chan);
}
}
uint8_t mavlink_check_target(uint8_t sysid, uint8_t compid)
{
if (sysid != mavlink_system.sysid)
return 1;
// Currently we are not checking for correct compid since APM is not passing mavlink info to any subsystem
// If it is addressed to our system ID we assume it is for us
return 0; // no error
}
// return a MAVLink variable type given a AP_Param type
uint8_t mav_var_type(enum ap_var_type t)
{
if (t == AP_PARAM_INT8) {
return MAVLINK_TYPE_INT8_T;
}
if (t == AP_PARAM_INT16) {
return MAVLINK_TYPE_INT16_T;
}
if (t == AP_PARAM_INT32) {
return MAVLINK_TYPE_INT32_T;
}
// treat any others as float
return MAVLINK_TYPE_FLOAT;
}
/// Read a byte from the nominated MAVLink channel
///
/// @param chan Channel to receive on
/// @returns Byte read
///
uint8_t comm_receive_ch(mavlink_channel_t chan)
{
uint8_t data = 0;
switch(chan) {
case MAVLINK_COMM_0:
data = mavlink_comm_0_port->read();
break;
case MAVLINK_COMM_1:
data = mavlink_comm_1_port->read();
break;
#if MAVLINK_COMM_NUM_BUFFERS > 2
case MAVLINK_COMM_2:
data = mavlink_comm_2_port->read();
break;
#endif
default:
break;
}
return data;
}
/// Check for available transmit space on the nominated MAVLink channel
///
/// @param chan Channel to check
/// @returns Number of bytes available
uint16_t comm_get_txspace(mavlink_channel_t chan)
{
if ((1U<<chan) & mavlink_locked_mask) {
return 0;
}
int16_t ret = 0;
switch(chan) {
case MAVLINK_COMM_0:
ret = mavlink_comm_0_port->txspace();
break;
case MAVLINK_COMM_1:
ret = mavlink_comm_1_port->txspace();
break;
#if MAVLINK_COMM_NUM_BUFFERS > 2
case MAVLINK_COMM_2:
ret = mavlink_comm_2_port->txspace();
break;
#endif
default:
break;
}
if (ret < 0) {
ret = 0;
}
return (uint16_t)ret;
}
/// Check for available data on the nominated MAVLink channel
///
/// @param chan Channel to check
/// @returns Number of bytes available
uint16_t comm_get_available(mavlink_channel_t chan)
{
if ((1U<<chan) & mavlink_locked_mask) {
return 0;
}
int16_t bytes = 0;
switch(chan) {
case MAVLINK_COMM_0:
bytes = mavlink_comm_0_port->available();
break;
case MAVLINK_COMM_1:
bytes = mavlink_comm_1_port->available();
break;
#if MAVLINK_COMM_NUM_BUFFERS > 2
case MAVLINK_COMM_2:
bytes = mavlink_comm_2_port->available();
break;
#endif
default:
break;
}
if (bytes == -1) {
return 0;
}
return (uint16_t)bytes;
}
/*
send a buffer out a MAVLink channel
*/
void comm_send_buffer(mavlink_channel_t chan, const uint8_t *buf, uint8_t len)
{
switch(chan) {
case MAVLINK_COMM_0:
mavlink_comm_0_port->write(buf, len);
break;
case MAVLINK_COMM_1:
mavlink_comm_1_port->write(buf, len);
break;
#if MAVLINK_COMM_NUM_BUFFERS > 2
case MAVLINK_COMM_2:
mavlink_comm_2_port->write(buf, len);
break;
#endif
default:
break;
}
}
static const uint8_t mavlink_message_crc_progmem[256] PROGMEM = MAVLINK_MESSAGE_CRCS;
// return CRC byte for a mavlink message ID
uint8_t mavlink_get_message_crc(uint8_t msgid)
{
return pgm_read_byte(&mavlink_message_crc_progmem[msgid]);
}
extern const AP_HAL::HAL& hal;
/*
return true if the MAVLink parser is idle, so there is no partly parsed
MAVLink message being processed
*/
bool comm_is_idle(mavlink_channel_t chan)
{
mavlink_status_t *status = mavlink_get_channel_status(chan);
return status == NULL || status->parse_state <= MAVLINK_PARSE_STATE_IDLE;
}