Eggtimer Rocketry
Eggtimer TRS

Eggtimer TRS (Total Recovery System) 

The Eggtimer TRS is an integrated flight computer and GPS rocket-recovery solution.  In one device, you get two channels of electronic parachute deployment (Drogue and Main) to bring your rocket down safely, and GPS tracking so you can find exactly where your rocket landed.  Like the "classic" Eggtimer, it records up to 32 flights so you can download both flight statistics and detail data, and you can easily import the CSV-formatted data into Excel or any graphing software.  NMEA-formatted GPS location data is streamed real-time to an Eggfinder receiver, so you can walk right up to your rocket after it lands.  

Used in conjunction with the Eggfinder LCD receiver, you can set the flight settings, test the deployment channels, get battery condition and channel continuity status, and arm the TRS to start a flight, all remotely.  You also get real-time altitude and channel continuity status during your flight.  You can also review the major flight milestones (apogee, maximum velocity, deployment altitudes, etc.) remotely without having to use a data cable.

The TRS' deployment circuitry is based on the time-tested Eggtimer Flight Computer, incorporating the same brownout-proof and mach-immune features.  You can use separate batteries for the computer and deployment side if you wish, to guarantee that even a dead short on the deployment side can't affect the flight computer and GPS functions.  You can also use it with a single battery, too (2S 7.4V LiPo batteries recommended).  Mach-immunity from premature parachute deployments is built-in and automatic; you don't have to set any timers or do anything at all.  You can use the TRS as the primary deployment controller in your rocket, or you can set the drogue and main deployments to fire later so it can be used as a backup controller in projects that require redundant deployment systems.

The GPS side is compatible with the Eggfinder Tracking System, you can use it with either the Eggfinder RX "dongle" receiver or the Eggfinder LCD handheld receiver.   Besides the features that those receivers provide, you can program the TRS' frequency to match your Eggfinder receiver, and additionally use any of up to 8 ID codes if you have the Eggfinder LCD receiver, so it's possible to have up to 72 TRS units operating simultaneously without interference.

Size is about 3.9" x 1.3" (+ 3.2" for the wire antenna, or about 1/2" for an RP-SMA connector for an external antenna).  It fits just fine in a 38mm coupler.  Weight is about 25 grams.   Like other Eggtimer Rocketry products, it is a kit... that means that you have to solder it together.  Construction is similar to the Eggfinder TX transmitter, except that most of the through-hole passive components have been made surface-mount to make the board a bit smaller and more robust.  They're all 0805 sized, so if you have a lighted magnifier you shouldn't have any trouble soldering them... we include special .020" no-clean low-temperature solder to make it easier.