How to use TeleMetrum?

Hello everyone,
I am new to the HPR also rocketry in general, I have a few questions which I cannot find an answer anywhere online.
We're, as a team, building a rocket that goes up to 3 kilometers and I am dealing with the electronics part. I came across with TeleMetrum first, it seemed like it satisfies most of our needs but I am not sure if I can programme it myself. Like arduino or teensy. If so, how do I do it? For example, I want Telemetrum to give 3amp current for just 5 seconds then 1amp for the whole flight can I do that? And how does TeleMetrum deploys the chutes? With the current flow? Basically, how do we use and control it? Also, did you have any problems with Telemetrum?
Additionally, do you think if it is better to design a custom PCB with sensors and microcontroller and everything?

Let me guess, engineer student, senior project. You guys get dumped into HPR without a mentor. Been there done that. It’s a f***ing nightmare without a mentor. There’s all this hobby knowledge out on the real launch day that you simply can’t research everything on the net. Go to a HPR launch site and find a high power rocketry mentor if able before your project launches. It will go smoother. Trust me. It’s the hobbyists details and methods not in books. It matters. People will show you how to pack chutes and rig shock cords right and set up dual deployment in person.

With Altus metrum products you download software AltusOS. It has a UI interface which you can configure the device settings.
You control Telemetrum products through a base the blue dongle starter pack and a teledongle laptop pack or the wireless teleBT option. Some of the products like TeleGPS use a data cable while on ground to set a frequency first using the downloadable software. You’ll need a FCC technician license to operate it. Visit a ham radio club take a test wait for FCC to grant permission first before turning device on. Your best bet is dig through the manual then play with device. Post more questions after playing with it.

For parachute deployments there should be a drogue chute (Apogee) channel, a main chute channel, and back up channels. I have the Telemini dual deploy altimeter and a teleGPS tracker. Telemini auto detects Apogee highest point via barometer then the user on ground configures the main deployment altitude using Altus software. No programming language skills required but you do wireless configure it after plugging battery in. You’ll need MJG firewires to ignite electronically a parachute deployment charge of about 1-1.5 grams or more of FFFG make sure to size the charge for the size of rocket appropriately and ground test it. Make sure chutes deploy on ground first while testing. You’ll want a Featherweight magnetic switch or other kind of switch for safe arming of electronics while rocket is on launch rail. Bottom line you need a switch for safety.

Having done two senior design projects and placing third then first in national engineering rocketry competitions I would not make the recommendation to alter the device or go custom route. The device will have enough amperage to ignite fire-wires and e matches. Spend the effort on using off the shelf hardware and have a backup system. (This is complex enough, don’t make the mistake of designing all own components.) And... we spent our efforts on custom airframe components which paid off big time. Mentor the next team your school has. Pass knowledge on.

Sorry if my answer isn’t the best I don’t have that specific Altus model. The process of using it is similar. If you can’t get a mentor. This forum will mentor you. It saved my arse and my grade. Do not underestimate recovery or deadlines.

Subscribe to Altus Metrum mailing list. Post your question and you should get a response pretty quickly.
https://lists.gag.com/mailman/listinfo/altusmetrum

Andrew_ASC said:

You’ll need MJG firewires to ignite electronically a parachute deployment charge of about 1-1.5 grams or more of FFFG make sure to size the charge for the size of rocket appropriately and ground test it.

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I didn't fully understand this part. Could you explain a bit more? So the telemetrum uses current flow to fire the chutes?

You are almost right, it's not a senior project but yes I am an engineering student. We'll participate in a national HPR competition. Thanks for all the advice, I will come back with more questions.

timbucktoo said:

Subscribe to Altus Metrum mailing list. Post your question and you should get a response pretty quickly.
https://lists.gag.com/mailman/listinfo/altusmetrum

Click to expand...

THANKS A LOT! I really needed this.

Telemetrum will send a current to a FireWire initiator when connected to the device at the programmed values based on data it collects in flight.

The FireWire then burns after current is applied and ignites a small black powder charge that you compress in a enclosure so it pressurizes rapidly similar to an explosion releasing a lot of gaseous vapors and forcing the parachute out of the rocket safely.

https://electricmatch.com/pyrotechnics/see/6/5/mjg-firewire-initiator

You can get Firewires here they are non ATF items. You’ll have to source black powder and charge containers separately for parachute deployment to work. FFFG is the grain size recommended by hobbyists but other sizes may work in a pinch.

Thank you Andrew_ASC, now i have a different question. It may sound silly but i couldn't figure it out. So do we need to TeleDongle in order to control Telemetrum? And you said you have Telemini and Telegps, how are they different? Can I use TeleGPS to control Telemetrum?

If you just need deployment control, there are many simpler options than the Telemetrum which may be easier for you to deal with.

Willyw said:

Thank you Andrew_ASC, now i have a different question. It may sound silly but i couldn't figure it out. So do we need to TeleDongle in order to control Telemetrum? And you said you have Telemini and Telegps, how are they different? Can I use TeleGPS to control Telemetrum?

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Read the section about products.
https://altusmetrum.org/

Willyw said:

Thank you Andrew_ASC, now i have a different question. It may sound silly but i couldn't figure it out. So do we need to TeleDongle in order to control Telemetrum? And you said you have Telemini and Telegps, how are they different? Can I use TeleGPS to control Telemetrum?

Click to expand...

Yes, you need TeleDongle+laptop or TeleBT+smart phone to control and initial configure settings on the TeleMetrum and receive data from it during ground tests or flight. The Teledongle acts as a receiver. The Telemetrum acts as live telemetry a transceiver because it receives and transmits data.

Telemini is a dual deploy altimeter with a tracking RDF beacon (a radio beacon). TeleGPS is a small tracker GPS only that communicates with satellites and the ground station (tele dongle). The main difference is TeleGPS will not fire pyro charges. Telemetrum combined all of these features.

In addition to Teledongle.

You’ll need at a minimum a
Yaseu VX-6R with a quality signal meter if you want to use the radio beacon on the Telemetrum.

Add a Yagi 440-3 or -5 from Arrow Antennas.

Add bNC to SMA cables.

add Arrow Antenna 4Mhz offset antenuator (if you plan to use radio beacon tracking capability)

Otherwise just a Yagi and baofeng UV-5R will work for GPS provided you input the coordinates from laptop or smartphone into another device manually to go find the rocket.