The Eggfinder is a GPS telemetry system that sends out a stream of NMEA-formatted serial data from a transmitter located in your rocket to a receiver on the ground. The purpose is to track your rocket in flight, and more importantly get it back. Using an integrated GPS module, the Eggfinder transmitter sends out a position update once a second, giving you the exact latitude and longitude of the rocket at that point in time. If you have the Eggfinder LCD receiver, you’ll get the coordinates displayed on the screen, which can be plugged into a navigation app on your phone, or you can get the optional LCD-GPS Module and it will show you exactly which way to go and how far without any additional equipment. With the optional Voice Module, it will literally “tell” you where to go… great for those long recoveries where you may have to drive out to the rocket.
If you use the RX “dongle” receiver with a PC or Android, the data can be fed real-time into a number of free software programs to track your rocket, and if using something like Google Earth or MapSphere you can actually get a map that will show you where your rocket landed. If you have a GPS-enabled smartphone like an iPhone or Android, you can plug the landing coordinates into an application such as MotionX and you can literally walk right up to your rocket.
Like other Eggtimer Rocketry products, the Eggfinders are sold as kits, depending on your options a complete system can be had for as little as $100. This makes an Eggfinder the least expensive GPS tracking system on the market. We use RF radio modules that transmit on the 900 MHz license-free ISM band at 100 mW, and have tracked rockets over six miles away. This makes the Eggfinder an ideal tracking solution for those situations in which your rocket may not be strato-busting but may go out of sight and therefore be difficult to find.
We pre-mount any parts that aren’t hand-solderable (i.e. the GPS modules, which are a leadless package) to make it easier on you. The surface mount parts are at least 0805-size (we prefer 1206 if we can fit them on the board), and the IC’s have at least a 1.27mm/.050″ pitch, so with a decent iron and tip you shouldn’t have any trouble soldering them.
Eggfinder TX Transmitter Kit: $70 Degree of Assembly Difficulty: 3/5
The Eggfinder TX transmitter is our “basic” transmitter, designed to be mounted in the nose cone of most hobby rockets. It measures about .9″ x 3″, and the antenna adds about another 3″. It can easily fit in the nose cone of a 38mm or 54mm rocket, and can fit into a 29mm coupler if you have enough length. The Eggfinder TX will also take an OpenLog datalogger module, so you can save your NMEA-formatted data to a micro-SD card so you can import the data into a program like Google Earth and get a really cool track of your rocket’s path. You can program it to any one of 72 frequency/ID combinations using the included pairing cable with an Eggfinder LCD receiver (non-US frequncies/ID’s may vary).
Eggfinder Mini Transmitter Kit: $75 Degree of Assembly Difficulty: 3/5
The Eggfinder Mini is the smallest GPS transmitter available, a mere .7″ side x 3.25″ long INCLUDING the antenna. It will even fit into an 18mm body tube, and it uses a special stubby antenna to make it even smaller. It’s so small that you can easily wrap it up in a Nomex “burrito” and attach it to your shock cord… no special sled necessary. There are some 3D-printed mounts available specifically to mount it in a 29mm or 38mm nose cone. It is functionally identical to the Eggfinder TX transmitter, except that there’s no place to add an OpenLog datalogger (just no room…)
Eggfinder RX “Dongle” Receiver KIt: $35 (includes ext. antenna) Degree of Assembly Difficulty: 2/5
Our “basic” receiver, the Eggfinder RX plugs into your Windows laptop (with the USB cable option) and can be used with software such as MapSphere to track your rocket in real time. With the Bluetooth option, you can send the GPS data to an Android device and get the coordinates and the track of your rocket using programs such as GPS Rocket Locator or Rocket Tracker. It’s ideal for setting up a “ground station” receiver with a laptop/tablet to get a real-time track of your rocket.
Eggfinder LCD Handheld Receiver Kit: $55 Degree of Assembly Difficulty: 2/5
The Eggfinder LCD receiver has a display that shows you the GPS coordinates, GPS altitude, and some fix quality informtion, and can be easily taken with you to retrieve your rocket so you have the most current GPS location as you approach it. You can also add a Bluetooth module to it so you can use it for real-time tracking with an Android device, as well as having the GPS coordinates displayed. It’s an extensible platform (just had to throw some buzz words in…), so there are things that you can add onto it to make it even better… see below.
Eggfinder LCD-GPS Module Kit: $40 Degree of Assembly Difficulty: 3/5
The Eggfinder LCD-GPS Module is an add-on for the Eggfinder LCD receiver, it gives you a single-device tracking solution… no phone/tablet/laptop required. In addtion to the standard GPS coordinate and GPS ASL altitude display, you also get the distance to your rocket, its compass heading in relation to you, your track (the compass heading that you’re moving at), and (the best part…) an arrow and bearing to your rocket. You just follow the arrow and it will literally take you right to your rocket. It’s the easiest tracking solution around!
Eggtimer Voice Module Kit: $20 Degree of Assembly Difficulty: 2/5
The Eggtimer Voice Module is an add-on for the Eggfinder LCD receiver, when used with an Eggfinder GPS transmitter it will speak out your rocket’s compass direction and distance from your set waypoint. If you have the Eggfinder LCD-GPS module in your LCD receiver, it will also literally tell you which way you need to go and how far to get your rocket. Plug it into the AUX jack on your vehicle’s stereo, and you can concentrate on where you’re going instead of looking down at the display all the time. It’s ideal for those long recoveries in rough terrain! If you have an Eggtimer TRS (or an Eggtimer altimeter with the Eggtimer Telemetry Module) it will speak out your real-time altitude, apogee, and deployment events too. It’s great for letting everybody know how awesome your flight is!
About our Degree of Difficulty Scale…
We rate Degree of Difficulty from 1 to 5, based on how small the parts are, how many parts there are, how long it takes to build, and how critical to proper operation minor soldering mistakes would be. A kit rated 1 is all through-hole, and is relatively forgiving of less than perfect solder joints. A kit rated 5 has a lot of small 0805 surface mount parts, and has .050″ pitch IC’s. If you’ve never built a kit before we recommend that you stay with the lower numbered kits, once you have successfully built a few of them then you can tackle the 4’s and 5’s.