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Add back AP_GPS_IMU to provide Xplane functionality 

git-svn-id: https://arducopter.googlecode.com/svn/trunk@1504 f9c3cf11-9bcb-44bc-f272-b75c42450872
This commit is contained in:
deweibel@gmail.com 2011-01-17 01:50:34 +00:00
parent 709b56f477
commit c9788d7b0b
3 changed files with 271 additions and 0 deletions
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1
libraries/AP_GPS/AP_GPS.h
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@ -13,3 +13,4 @@
#include "AP_GPS_Auto.h" #include "AP_GPS_Auto.h"
#include "AP_GPS_HIL.h" #include "AP_GPS_HIL.h"
#include "AP_GPS_Shim.h" // obsoletes AP_GPS_HIL, use in preference #include "AP_GPS_Shim.h" // obsoletes AP_GPS_HIL, use in preference
#include "AP_GPS_IMU.h" // temporarily reinstated for Xplane support

226
libraries/AP_GPS/AP_GPS_IMU.cpp Normal file
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// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: t -*-
/*
GPS_MTK.cpp - Ublox GPS library for Arduino
Code by Jordi MuÒoz and Jose Julio. DIYDrones.com
This code works with boards based on ATMega168/328 and ATMega1280 (Serial port 1)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
GPS configuration : Costum protocol
Baud rate : 38400
Methods:
init() : GPS initialization
update() : Call this funcion as often as you want to ensure you read the incomming gps data
Properties:
lattitude : lattitude * 10000000 (long value)
longitude : longitude * 10000000 (long value)
altitude : altitude * 100 (meters) (long value)
ground_speed : Speed (m/s) * 100 (long value)
ground_course : Course (degrees) * 100 (long value)
new_data : 1 when a new data is received.
You need to write a 0 to new_data when you read the data
fix : 1: GPS NO fix, 2: 2D fix, 3: 3D fix.
*/
#include "AP_GPS_IMU.h"
#include "WProgram.h"
// Constructors ////////////////////////////////////////////////////////////////
AP_GPS_IMU::AP_GPS_IMU(Stream *s) : GPS(s)
{
}
// Public Methods //////////////////////////////////////////////////////////////
void
AP_GPS_IMU::init(void)
{
// we expect the stream to already be open at the corret bitrate
}
// optimization : This code doesn't wait for data. It only proccess the data available.
// We can call this function on the main loop (50Hz loop)
// If we get a complete packet this function calls parse_IMU_gps() to parse and update the GPS info.
bool
AP_GPS_IMU::read(void)
{
byte data;
int numc = 0;
static byte message_num = 0;
numc = _port->available();
if (numc > 0){
for (int i=0;i<numc;i++){ // Process bytes received
data = _port->read();
switch(step){ //Normally we start from zero. This is a state machine
case 0:
if(data == 0x44) // IMU sync char 1
step++; //OH first data packet is correct, so jump to the next step
break;
case 1:
if(data == 0x49) // IMU sync char 2
step++; //ooh! The second data packet is correct, jump to the step 2
else
step=0; //Nop, is not correct so restart to step zero and try again.
break;
case 2:
if(data == 0x59) // IMU sync char 3
step++; //ooh! The second data packet is correct, jump to the step 2
else
step=0; //Nop, is not correct so restart to step zero and try again.
break;
case 3:
if(data == 0x64) // IMU sync char 4
step++; //ooh! The second data packet is correct, jump to the step 2
else
step=0; //Nop, is not correct so restart to step zero and try again.
break;
case 4:
payload_length = data;
checksum(payload_length);
step++;
if (payload_length > 28){
step = 0; //Bad data, so restart to step zero and try again.
payload_counter = 0;
ck_a = 0;
ck_b = 0;
//payload_error_count++;
}
break;
case 5:
message_num = data;
checksum(data);
step++;
break;
case 6: // Payload data read...
// We stay in this state until we reach the payload_length
buffer[payload_counter] = data;
checksum(data);
payload_counter++;
if (payload_counter >= payload_length) {
step++;
}
break;
case 7:
GPS_ck_a = data; // First checksum byte
step++;
break;
case 8:
GPS_ck_b = data; // Second checksum byte
// We end the IMU/GPS read...
// Verify the received checksum with the generated checksum..
if((ck_a == GPS_ck_a) && (ck_b == GPS_ck_b)) {
if (message_num == 0x02) {
join_data();
} else if (message_num == 0x03) {
GPS_join_data();
} else if (message_num == 0x04) {
join_data_xplane();
} else if (message_num == 0x0a) {
//PERF_join_data();
} else {
// _error("Invalid message number = %d\n", (int)message_num);
}
} else {
// _error("XXX Checksum error\n"); //bad checksum
//imu_checksum_error_count++;
}
// Variable initialization
step = 0;
payload_counter = 0;
ck_a = 0;
ck_b = 0;
break;
}
}// End for...
}
}
/****************************************************************
*
****************************************************************/
void AP_GPS_IMU::join_data(void)
{
//Verifing if we are in class 1, you can change this "IF" for a "Switch" in case you want to use other IMU classes..
//In this case all the message im using are in class 1, to know more about classes check PAGE 60 of DataSheet.
//Storing IMU roll
roll_sensor = *(int *)&buffer[0];
//Storing IMU pitch
pitch_sensor = *(int *)&buffer[2];
//Storing IMU heading (yaw)
ground_course = *(int *)&buffer[4];
imu_ok = true;
}
void AP_GPS_IMU::join_data_xplane()
{
//Storing IMU roll
roll_sensor = *(int *)&buffer[0];
//Storing IMU pitch
pitch_sensor = *(int *)&buffer[2];
//Storing IMU heading (yaw)
ground_course = *(unsigned int *)&buffer[4];
//Storing airspeed
airspeed = *(int *)&buffer[6];
imu_ok = true;
}
void AP_GPS_IMU::GPS_join_data(void)
{
longitude = *(long *)&buffer[0]; // degrees * 10e7
latitude = *(long *)&buffer[4];
//Storing GPS Height above the sea level
altitude = (long)*(int *)&buffer[8] * 10;
//Storing Speed
speed_3d = ground_speed = (float)*(int *)&buffer[10];
//We skip the gps ground course because we use yaw value from the IMU for ground course
time = *(long *)&buffer[14];
imu_health = buffer[15];
new_data = true;
fix = true;
}
/****************************************************************
*
****************************************************************/
// checksum algorithm
void AP_GPS_IMU::checksum(byte data)
{
ck_a += data;
ck_b += ck_a;
}

44
libraries/AP_GPS/AP_GPS_IMU.h Normal file
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// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: t -*-
#ifndef AP_GPS_IMU_h
#define AP_GPS_IMU_h
#include <GPS.h>
#define MAXPAYLOAD 32
class AP_GPS_IMU : public GPS {
public:
// Methods
AP_GPS_IMU(Stream *s);
virtual void init(void);
virtual bool read(void);
// Properties
long roll_sensor; // how much we're turning in deg * 100
long pitch_sensor; // our angle of attack in deg * 100
int airspeed;
float imu_health;
uint8_t imu_ok;
private:
// Packet checksums
uint8_t ck_a;
uint8_t ck_b;
uint8_t GPS_ck_a;
uint8_t GPS_ck_b;
uint8_t step;
uint8_t msg_class;
uint8_t message_num;
uint8_t payload_length;
uint8_t payload_counter;
uint8_t buffer[MAXPAYLOAD];
void join_data();
void join_data_xplane();
void GPS_join_data();
void checksum(unsigned char data);
};
#endif