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 one of the latest integrated GPS modules, 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. This 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 $90. 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 attained a clear-air range of over 3 miles with no signal loss (the rocket went way out of sight but starting coming down before we ran out of signal!) If you change out the included 1/4 wave “stick” antenna on the receiver for a RP-SMA connector and our optional external “rubber duckie” antenna, you can easily double this range… we’ve tracked rockets over 5 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.
Even though the GPS module and the RF transceiver modules are surface mount modules, they are not terribly difficult to solder onto the board; we include special .020″ low-temperature no-clean solder to make it easier. If you have any prior kit-building experience (i.e. you’ve build an Eggtimer Flight Computer) then putting an Eggfinder together will be a breeze.
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: 4/5
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…)
Eggtimer TRS GPS Tracker/Flight Computer Kit: $90 Degree of Assembly Difficulty: 5/5
The Eggtimer TRS combines GPS tracking features of the Eggfinder TX transmitter with the basic flight computer functions of the Eggtimer Classic altimeter. You get the same GPS tracking features as the Eggfinder TX, but you also get two output channels for electronic deployments. Most functions can be controlled remotely using the Eggfinder LCD receiver… programming, continuity/voltage status, arming, and remote deployment testing (it makes testing with live charges a lot easier!).
Eggfinder RX “Dongle” Receiver KIt: $25 Degree of Assembly Difficulty: 2/5
Our “basic” receiver, the Eggfinder RX plugs into your 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
(Shown with TX transmitter)
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. In addition, we make a GPS module add-on for the LCD receiver, which gives you a single-device tracking solution. You get the the distance to your rocket, its compass direction in relation to you, your track (the compass direction that you’re moving), and the best part… an arrow and bearing to your rocket. You follow the arrow and it literally takes you to your rocket. It’s about the easiest tracking solution there is. 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.
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!
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.