Best Radio Module for Telemetry?

[diyaerospace]

Hello,
In the past few months, I have developed an altimeter that logs onboard data to a micro SD card. Since I plan on using this for my L1 I think it could be cool to send onboard data back to a ground station. I have found several projects on long-range communication and other rocket telemetry systems. They all use different radio transmitters and receivers and I would like some guidance on which one is ideal for my specific application.

I don't plan on flying over 3000 ft so I don't need super long-range communication. It would also be ideal if I could display the ground station data on my laptop in real-time using a program that I will write in processing or python. I currently have two RFM69 radios from adafruit that I used for a separate project, could these be used for the transmit telemetry? It would be a huge help if someone who has had success with telemetry before could send me some code if that is possible.

Thanks,
Walter

 

[waltr]

900MHz?
These LoRa transceivers do work well and reported to have good range.
3000feet line of sight would be no problem even with rubber duckies on each end.

I have read on this forum about people using 900MHz LoRa. Do a search to read about them.

Eggfinders use 900MHz Hope RF modules for the GPS telemetry. Work very well out to a few miles. The optional 400MHz modules (Requires an FCC ham radio license) go 10's of miles and is only needed if rocket is going very high and expected to recover miles away.

 

[diyaerospace]

900MHz?
These LoRa transceivers do work well and reported to have good range.
3000feet line of sight would be no problem even with rubber duckies on each end.

I have read on this forum about people using 900MHz LoRa. Do a search to read about them.

Eggfinders use 900MHz Hope RF modules for the GPS telemetry. Work very well out to a few miles. The optional 400MHz modules (Requires an FCC ham radio license) go 10's of miles and is only needed if rocket is going very high and expected to recover miles away.

I have this just the " non-feather " variant.
https://www.adafruit.com/product/3230They are 433Mhz.

 

[waltr]

Yes, these will have good range with a proper antenna (antenna is the key) and great for telemetry. That board has option for an SMA connector for a rubber duck or other antenna.
Adafruit's tutorials are good and they should have code examples (Ardinuo) to setup and operate these RF modules.

However:

RFM69 @ 433 MHz - basic packetized FSK/GFSK/MSK/GMSK/OOK radio at 433 MHz for use in Europe ITU 1 license-free ISM, or for amateur use with restrictions (check your local amateur regulations!)

This one REQUIRES an FCC Ham Radio license to legally operate.

A Technician Class license is easy to get. Its a simple written test.
Look up the ARRL for details about getting your ham license.

 

[Hobie1dog]

However:

This one REQUIRES an FCC Ham Radio license to legally operate.

A Technician Class license is easy to get. Its a simple written test.
Look up the ARRL for details about getting your ham license.

you just have to know the answers to all 426 questions in the pool.

 

[diyaerospace]

Does anyone know if there are any other radios that I can use that don't require a Ham Radio License? I am 14 years old and I don't know if I will be able to take the test.

Thanks,
Walter

 

[Titan II]

I am 14 years old and I don't know if I will be able to take the test.

Yes you can and the test is a no brainer. Just Google it for all the info.

 

[heada]

Does anyone know if there are any other radios that I can use that don't require a Ham Radio License? I am 14 years old and I don't know if I will be able to take the test.

Thanks,
Walter

RFM95 is the 900MHz version of the RFM69 module and does not require a HAM license.

https://www.adafruit.com/product/3072
The examples show how to use both and the Arduino code is nearly the same between them.

 

[OverTheTop]

The RFD900 series of modems is great. Probably a bit more expensive than the modules you are looking at.
http://rfdesign.com.au/products/
Over 40km range is quoted. Some products feature multiple antennas and diversity switching. Up to 1W transmit power.

Based on my experience these are really clean transceivers and have great features and performance.

There are Chinese knock-offs of these but they have less performance apparently.

 

[Hobie1dog]

Does anyone know if there are any other radios that I can use that don't require a Ham Radio License? I am 14 years old and I don't know if I will be able to take the test.

It doesn't make a difference how young you are. Anybody can take the test and you can go to a website like eham.net and they have practice test, and after taking the practice test 20 or 30 times you will probably get to the point of reaching the 85% mark which is what you need to be up to before you attempt to take the test.

 

[plugger]

About the only thing I'd recommend that hasn't been mentioned is to stay away from FHSS radios. Having your comms on a single static frequency is very useful if you'd like to RDF the transmitter to find the rocket.

 

[waltr]

Yep, the 900MHz versions are License free.


Some other threads on this subject:
https://www.rocketryforum.com/threads/rfm95w-transceiver-convert-packet-to-variables.171060/
https://www.rocketryforum.com/threa...ht-computers-or-the-meshtastic-system.174244/
https://www.rocketryforum.com/threa...hz-rdf-ranging-and-altitude-telemetry.150446/
I'm sure there are more if you search.

 

[bdureau]

I have been using 3DR chinese clones as well as Lora modules with great success (433Mhz and 900Mhz) for my talking telemetry

 

[John Kemker]

you just have to know the answers to all 426 questions in the pool.

Not that difficult. Go to http://www.hamexam.org or http://www.hamexam.com (first is free, second has a subscription) and keep taking it until you can pass on a regular basis.

Does anyone know if there are any other radios that I can use that don't require a Ham Radio License? I am 14 years old and I don't know if I will be able to take the test.

Thanks,
Walter

There are licensed hams that are as young as 8 years old. No age requirement to take the test or get the license.

Please don't let the test scare you off.

 

[waltr]

For some research check what Eggtimer has:
http://eggtimerrocketry.com/eggtimer-telemetry-faqs/