ardupilot/libraries/AP_GPS/AP_GPS_406.cpp

90 lines
3.4 KiB
C++

// -*- 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/>.
*/
//
// GPS_406.cpp - 406 GPS library for Arduino
// Code by Michael Smith, Jason Short, Jordi Muñoz and Jose Julio. DIYDrones.com
// This code works with boards based on ATMega168/328 ATMega1280 (Serial port 1)
//
#include <AP_HAL.h>
#include "AP_GPS_406.h"
extern const AP_HAL::HAL& hal;
static const char init_str[] = "$PSRF100,0,57600,8,1,0*37";
// Public Methods ////////////////////////////////////////////////////////////////////
void AP_GPS_406::init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting)
{
_change_to_sirf_protocol(); // Changes to SIRF protocol and sets baud rate
_configure_gps(); // Function to configure GPS, to output only the desired msg's
AP_GPS_SIRF::init(s, nav_setting); // let the superclass do anything it might need here
}
// Private Methods //////////////////////////////////////////////////////////////
void
AP_GPS_406::_configure_gps(void)
{
const uint8_t gps_header[] = {0xA0, 0xA2, 0x00, 0x08, 0xA6, 0x00};
const uint8_t gps_payload[] = {0x02, 0x04, 0x07, 0x09, 0x1B};
const uint8_t gps_checksum[] = {0xA8, 0xAA, 0xAD, 0xAF, 0xC1};
const uint8_t gps_ender[] = {0xB0, 0xB3};
for(int16_t z = 0; z < 2; z++) {
for(int16_t x = 0; x < 5; x++) {
_port->write(gps_header, sizeof(gps_header)); // Prints the msg header, is the same header for all msg..
_port->write(gps_payload[x]); // Prints the payload, is not the same for every msg
for(int16_t y = 0; y < 6; y++) // Prints 6 zeros
_port->write((uint8_t)0);
_port->write(gps_checksum[x]); // Print the Checksum
_port->write(gps_ender[0]); // Print the Ender of the string, is same on all msg's.
_port->write(gps_ender[1]); // ender
}
}
}
// The EM406 defalts to NMEA at 4800bps. We want to switch it to SiRF binary
// mode at a higher rate.
//
// The change is sticky, but only for as long as the internal supercap holds
// settings (usually less than a week).
//
void
AP_GPS_406::_change_to_sirf_protocol(void)
{
// this is a bit grody...
AP_HAL::UARTDriver *fs = (AP_HAL::UARTDriver*)_port;
fs->begin(4800);
hal.scheduler->delay(300);
_port->print(init_str);
hal.scheduler->delay(300);
fs->begin(9600);
hal.scheduler->delay(300);
_port->print(init_str);
hal.scheduler->delay(300);
fs->begin(GPS_406_BITRATE);
hal.scheduler->delay(300);
_port->print(init_str);
hal.scheduler->delay(300);
}