Arduino Balloon Tracking

The Ferret is a high-altitude balloon tracking hardware package. Created by [Adam Greig] and [Jon Sowman], it uses an Arduino to gather NMEA data from a GPS unit, format the data into a string, and transmit that string on narrow-band FM. The project, built in one afternoon, is a tribute to the prototyping simplicity the Arduino provides.

The unit was powered by four AA batteries, using the Arduino’s on board voltage regulator. This provided a bit of heat which helps in the frigid reaches of the upper atmosphere. The bundle above was put in a project box and attached to the outside of the balloon’s payload, then covered with foam for warmth and moisture resistance. This tracking is a lot less complicated than some of the photography setups we’ve seen for balloons. It’s also more versatile because it broadcasts the GPS data so that many people can track it, rather than just logging its location.

20 thoughts on “Arduino Balloon Tracking

  1. We stuck this payload on the side of someone else’s main payload, which included a video and still camera. I don’t think that person has written up their project online, but a video of some of the takeoff and some footage from high up in the atmosphere is at:

    includes bonus footage of the first launch attempt with too little helium where we nearly took out some footballers!

    There are some more photos of Ferret on my flickr:


  2. Interesting. Are there FCC issues with that Radiometrix NTX2 narrowband FM module? The site for the module says the standard frequencies are 434.075MHz, 434.650MHz and 458.700MHz.

  3. The NTX2 has a claimed range of 500M, but the website mentions tracking this thing as it went above 78000 feet (24 KM).

    Was it the antenna design (on either end) that made this possible?

  4. sol: Those frequencies are license-exempt in the UK, so we can use them unlicensed. Unfortunately UK amateur radio licenses do not allow airborne use so we cannot operate on normal amateur frequencies or power levels. In the US there are similar frequencies, but you can also use your amateur licenses airborne which nicely gets around the issue.

    Eric: 500m is about correct for on the ground, but as you guess antenna design (and other factors) significantly alter things. The NTX2 can only transmit 10mW of power, which is very, very little (amateurs will tend to use at least 10W and commonly 100W to 1kW for long range contacts).

    However, we have direct line of sight to the balloon while it’s in the sky that covers most of the country, which helps significantly; the antenna on the balloon has a radiation pattern that sends almost all the signal downwards with very little going up, which helps, and most importantly we use very sensitive amateur radios with high gain directional antennas to pick the balloon up:
    is Jon modelling the antenna we use.

    The maximum range we’ve got out of one of these modules with a suitable antenna and receiver was 400km, and at that point the balloon went over the horizon and so became impossible to receive. You can pick them up from a long way away!

  5. @sol

    This is from Radiomextrix’s website:
    “Available for licence-exempt operation in the 433MHz (EU) and 458MHz (UK) bands, the NTX2 & NRX2 modules combine effective screening with internal filtering to minimise spurious radiation and susceptibility thereby ensuring EMC compliance.”

    They’re a UK company, so they only mention Europe frequencies, but 433.05–434.79 MHz is a range within the ISM band here in the states so two of those frequencies would be alright to use.

    Granted, you could probably find cheaper transmitters/receivers out there that use the ISM band.

  6. Bob: I’m using an icom ic7000 with a homemade 8 element yagi for 434mhz, but people all over the country were picking up the balloon and used a variety of radios to do so, anything from a small handheld designed for hitting local repeaters to some very sensitive scanners with yagis on big masts on autorotators. The main thing is just to be able to pick up 434MHz SSB and output it to a computer for decoding in some form.

  7. “This tracking is a lot less complicated than some of the photography setups we’ve seen for balloons.”

    I honestly do not see how this could be less complex than the setup they linked to. That setup used a cellphone with a GPS unit in it, which had a piece of freeware installed on it, so that you could track its location online. That is a 5-10 minute process at most, not a full afternoon process.
    And as for letting multiple people track it, anyone who you give the password to, could track it online, without needing a special computer decoder.

  8. Adam, what site did you have make you the laser cut acrylic for your clock? I’m designing a nixie clock of my own and would love to be able to have someone do that bit for me.

    Excellent work on the balloon transmitter setup, the make-shift antenna is great.


  9. I am pretty sure the cellphone kept tracking the entire flight. They added an exterior antenna to boost the signal, yes, but still.
    IIRC the gps unit didn’t even celling out at any point, but it has been a while since I read their page.

  10. Well I read over it again, and you are right. The cellphone only sends in its location once it gets low enough. Still, some how they found their max altitude, so it must record or something.

  11. @natrium42
    I can’t recall when it happened, but a chap here had his day on the site when he was successful using a balloon and a foam cooler. The contents included a Cell wearing the usual accessories and an older Dell laptop. There were also some sensors, and I believe a webcam to watch the trip. It took two trips but he did accomplish the obvious. Half the problem was in preparing the foam cooler.

  12. @Adam Grieg
    I just visited the home page for your excellent project. It looks very good. Also the tracker site confirms that there is a new balloon aloft.

    However the Flickr site complains that one of the pictures happens to be not available.

  13. @GCL
    That looks like a test, not a real launch. The winds have been very bad in UK this week with predicted landings in the water.

    There quite a few payloads ready to be launched though (2 UK and 1 AUS), feel free to pop in to #highaltitude channel on FreeNode if you are interested.

  14. Hi,

    I’d really like to be able to make this myself, I have a Ardunio board on it’s way too me.
    I’m not great with electronics so is there a step by step guide at making one?

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