Eggtimer TRS - Dual-Deployment Controller with GPS/RF Tracking

Eggtimer Rocketry is pleased to announce the Eggtimer TRS (for "Total Recovery System"). In one device you get:

o Dual-deployment based on the same mach-immune and glitch-proof design as the Eggtimer Flight Computer
o 32-flight memory, flight summary and detail can be downloaded in TXT/CSV format to any computer
using the standard Eggtimer USB-TTL data cable (not included)
o GPS/RF tracking, compatible with Eggfinder RX and LCD receivers
o Range: Approx. 10,000', about double that using external "rubber duckie" antennas
o Frequency can be programmed using the USB-TTL data cable, plus support for 8 ID codes,
for a total of 72 possible combinations
o When used with the Eggfinder LCD receiver, you get:
- Remote deployment channel programming
- Remote battery and deployment channel status
- Remote arming for flight
- Flight summary display of all 32 flights
- Remote deployment channel testing
o Also, adds real-time baro altitude and deployment channel status to the standard Eggfinder LCD display
(in addition to NMEA coordinates, SiV, HDOP graph)

You can read more about it at:

https://www.eggtimerrocketry.com/page23.php

Like all Eggtimer Rocketry products, it's a kit. That means that you have to solder it together, of course, but in exchange for a bit of work you get an excellent value. The list price for the Eggtimer TRS is $90, availability will be just in time for the Black Friday (Black Week?) sales. Yes, that means that it will be discounted...

If you're interested, drop us an email at [email protected]. We'd like to get an idea of how many we're going to need to kit up ahead of the sales... we don't want to be caught short like we did for the last one! Thanks for your interest, and for your continued support!

Cris Erving
Eggtimer Rocketry

That's a very cool all-in-one solution.

Another cool product, Cris. You're on a roll.

Does the recorded flight data include the GPS co-ordinates?

It looks like it has out of the box single battery operation?

xenon said:

It looks like it has out of the box single battery operation?

Click to expand...

What he said. If this is single battery GPS + Altimeter, it's high on my list of prospective units. Dual battery is annoying.

Hmm count me in. Have thought about a micro altimeter with DD.

I'll assemble these too! I guess I will have to get myself one first so Im sure I know what I'm doing


https://www.rocketryforum.com/showthread.php?119859-Eggfinder-Eggtimer-Assembly

I wish it had an option to add accelerometers to get good velocity measurement for mach busting flights.


Sent from my iPhone using Rocketry Forum

Looks great...and I just finished assembling and testing my 3 Eggtimers today, all functioning nominally.

Count me in Cris!

I'll be in for at least one!

I suspected as much when I checked the website this AM and saw the ET TRS empty directories. I thought with the opt-isolation of the pyro channels it would be easier to combine both units and not have to worry about Rf interference. Sort of a poor man's Tele-Metrum but without all the two way communication bells and whistles that fine product has.

The only caution is no metallic paint on the rocket where the antenna is going to project and not to have all thread parallel to the antenna.
The unit begs for a bulkhead mount on the sustainer side of the ebay so it's out in the breeze at apogee. Something like this:
https://www.ebay.com/itm/cable-RP-S...Coaxial_Cables_Connectors&hash=item3f2eb8c2e1

The other thing one can do with a tight situation is drill a tight form fitting hole in the forward bulkhead and simply have the wire antenna
project into the main parachute bay. How does one keep it from getting smushed/squished by the main chute in a small rocket? Simple,
just put the cardboard tube that AT wire igniters come it to stent the antenna. Wrap it in duct tape for a little flame protection and use clay to
help "stick it" to the bulkhead. I've used this technique with great success in a Wildman Junior that has the Raven II riding aft in the ebay and
a Beeline GPS riding forward on the sled. The wire antenna projects into the main chute upper bay. No metallic paint and it has great range.

Remember, the Egg Timer uses a very simple serial interface that one "will have to" read the instructions. No fancy eye candy interface. For that trade off, one gets real economy with a programmable flight computer and now one with a GPS tracker onboard. No more lost rockets in standing corn. A compatriot at MWP 12 had a ship land in
the standing corn south of the launchsite but with a TLA GPS unit onboard, had no problemo finding it.
My WMJr. landed a little northwest of his project out in a harvested field but I didn't get a visual lock until I was
70' away with my Garmin 60Cs, D72 and BLGPS. Realtime GPS tracking really removes a lot of dread and saves
time in recovery. Kurt

Wow. Count me in. Well done!

Yes - very interested in this.

Also interested in where to get the correct freq rubber duck antennas. Price is not so much an issue as getting a good match to the freq range. Part numbers etc. would be helpful.

patelldp said:

What he said. If this is single battery GPS + Altimeter, it's high on my list of prospective units. Dual battery is annoying.

Click to expand...

You can set it up either way. I've flown it both ways. I flew it at ROCStock to 3700' on a Wildman Mini with an I204, using a 200 mah LiPo and Q2G2's. I also flew my Escape Velocity to 8K & Mach 1.2 on a J420, also single battery (350 mah LiPo). The difference between two batteries and one is basically one wire, since you have to put a switch inline with the + lead of the deployment battery (NAR/TRA rules).

For single battery use, my recommendation to prevent any chance of a short causing a problem is that you want your battery capacity (mah x C) to be at least 10x the all-fire current of the igniter. For example, if you are using a J-Tek which has about a 1 amp all-fire rating you'll need 10A, or 10,000 ma of current available. A 500 mah LiPo rated at 20C would do it, so would a 350 mah LiPo at 30C.

ksaves2 said:

Remember, the Egg Timer uses a very simple serial interface that one "will have to" read the instructions. ... Kurt

Click to expand...

You can also program it with the LCD receiver, that's one of the best things about it. I actually forgot my laptop when I left for ROC, no problem... you really only need it for programming the frequency, device name, and for downloading the detailed flight data.

In for one..you can drop ship it to ConMan - when the sale happens.

We were just talking about a remote, electronic confirmation that the Altimeter is armed - thought it would be a BlueTooth activated switch and app ...and here is the concept already shipping !

Way to go, Cris! And nice to see you flying at ROCstock also !

Kenny

If the EF LCD is flash updated to the new firmware for the TRS, will it still function nominally when used with a "plain" Egg Finder tracker?
Kurt

Yes, the only differences will be that 1) You need to select ID zero when you're setting the LCD frequency to match your Eggfinder TX (zero is the default anyway), and 2) There will be a short screen ("Waiting for Sync") while it looks for an Eggtimer TRS to pair with. If it doesn't get sync with one, it goes into the familiar "Waiting for Fix" screen.

I expect to have the Assembly and Users guides posted by the end of the week, along with the EF LCD firmware required to support the TRS.

matthew said:

Does the recorded flight data include the GPS co-ordinates?

Click to expand...

Just wondering..

matthew said:

Does the recorded flight data include the GPS co-ordinates?

Click to expand...

It does not, but you can get it real-time from your Eggfinder receiver either with a serial cable or Bluetooth, just like the Eggfinder TX.

I agonized over this, because in order to add that capability it would have required a substantial amount of extra hardware/software. The reason for that is because it would mean going to SPI flash instead of I2C EEPROM, and there aren't enough pins on an ATMEGA328 to handle everything. I would have either had to go to a larger Atmel chip (ATMEGA644, a 40-pin brute or a 44-pin QFP that would have to be pre-mounted), or something else. The Eggtimer TRS doesn't actually "read" the NMEA data stream, it does some multiplexing with the NMEA and altitude/status data from the MCU so that the additional data going to the receiver doesn't interfere with the NMEA stream. In order to save it to flash, I would have to read the data as a serial data stream and buffer it until I got enough data to write a page (since Flash has to be written a page at a time). The existing hardware can't do that.

Sometimes you have to make choices that are not necessarily optimal when you design something, this was one of them. On the other hand, the design goal was to create an integrated DD deployment controller with GPS tracking, so data gathering beyond what the Eggtimer does really wasn't in the cards.

The way I look at it, you're getting the regular Eggfinder (already an amazing value) plus all the capabilities of a dual deployment altimeter for only another $20. Too good to pass up - and the simplicity with the LCD display is hard to beat!

I want one with the LCD. Shipped to conman for assembly.

NikeMikey

NikeMikey said:

I want one with the LCD. Shipped to conman for assembly.

NikeMikey

Click to expand...

Looks like Connor is going to be busy. Oh well, he's young and tough. Kurt

ksaves2 said:

Looks like Connor is going to be busy. Oh well, he's young and tough. Kurt

Click to expand...

Lots of extra $$ for all the Black Sat sales!

cerving said:

It does not

Click to expand...

Thanks, Cris. I figured that if I was curious, others would be, too. For me, the remote arming will be worth the price of entry. I have a project on the go that this will be perfect for.

Does this require a lipo battery or can it be run with standard 9 volt alkaline?

I'll take 1.

terryg said:

Does this require a lipo battery or can it be run with standard 9 volt alkaline?

Click to expand...

If your ematch will fire with a 9V battery, it's fine to use one for the DEPLOYMENT power.

On the computer end, you can test it with a 9V battery but I wouldn't fly with one. They just don't have enough capacity, you'll be lucky to get more than an hour or two out of them. GPS's and RF take a lot of power.

If you want to run a single battery, you may if you observe the rule... your battery's mah capacity x the "C" rating must be at least 10 times the all-fire current of your ematch. A 350 mah 30C pack can handle J-Teks; a 200 mah 10C pack can handle Q2G2's. If you're going to use two batteries, you just need a deployment battery capable of firing your ematch and a computer battery that has enough capacity to handle however long you want it to run.

Always good to see you Chris-ROC 40 was great fun for me. I'm pretty sure Wayne and Sharon would give you superlative reviews as Sharon's wound up past the power lines after the drag race to 13k and she retrieved in good time thanks to your magic box!