_ The Arduino n' Gameduino _ _ | | Satellite Tracker
/ | ' \/ _ (-< |
_,|||__, //_| Written by Mark VandeWettering, K6HX, 2011
|/ brainwagon@gmail.com
Angst is an application that I wrote for the Arduino and Gameduino. It is being distributed under the so-called "2-class BSD License", which I think grants potential users the greatest possible freedom to integrate this code into their own projects. I would, however, consider it a great courtesy if you could email me and tell me about your project and how this code was used, just for my own continued personal gratification.
Angst includes P13, a port of the Plan 13 algorithm, originally written by James Miller, G3RUH and documented here:
http://www.amsat.org/amsat/articles/g3ruh/111.htmlOther implementations exist, even for embedded platforms, such as the qrpTracker library of Bruce Robertson, VE9QRP and G6LVB's PIC implementation that is part of his embedded satellite tracker. My own code was ported from a quick and dirty Python implementation of my own, and retains a bit of the object orientation that I imposed in that code.
While the P13 library is reasonably independent and can be used in other applications, the remainder of the code is fairly specific to the particular hardware I had on hand:
The Gameduino
James Bowman developed the Gameduino as an Arduino shield to
generate sound and graphics which might have been typical of
8 bit computers of the 1980s. It consists of a Xilinx FPGA,
programmed with a version of his J1 Forth processor, and
generates video and sound. It is programmed from the Arduino
using a simple set of commands sent over the I2C bus.You can find more information here:
http://excamera.com/sphinx/gameduino/A DS1307 RTC
Sparkfun has a Dallas Semiconductor DS1307 chip mounted on a
handly little breakout board. I used this chip to keep track
of time. It's not particularly great: it drifts by a couple
of minutes a week in my prototype: a better and more accurate
timepiece would enhance the usability of this prototype. I've
considered using a GPS to keep track of time, that extension is
left as an exercise for the motivated reader.An AT24C1024 Serial EEPROM
The ATMEGA328 used in the Arduino contains a mere 512 bytes of
EEPROM. This is enough space to store a few satellites, but I
wanted to have greater capacitity. So, I got some 128K byte
EEPROMS for about $4 from digikey. Each one of these can store
the data for about 750 satellites. My prototype just uses one,
but it's possible to chain up to four of them together.A Rotary Encoder
The entire interface is driven from a single rotary encoder w/ a built in switch, similar to this one:
http://www.sparkfun.com/products/9117 The code turns on the necessary internal pullup resistors to allow it to be directly wired to the Arduino input pins.
Currently the encoder is read in the polling main event loop. This means that quick motion of the encoder is not adequately tracked: consider this another exercise for the motivated reader.
I hope you enjoy the code, and find it useful and/or informative!
Copyright 2011, Mark VandeWettering. All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
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THIS SOFTWARE IS PROVIDED BY MARK VANDEWETTERING ''AS IS'' AND ANY
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The views and conclusions contained in the software and documentation are those of the authors and should not be interpreted as representing official policies, either expressed or implied, of Mark VandeWettering