Trackuino – An Open Source Arduino APRS Tracker

trackuino board

Trackuino is a new open source (GPLv2 license) Arduino APRS tracker designed by [Javier Martin]. If you are unfamiliar: APRS (Automatic Packet Reporting System) is an amateur radio method used to relay small packets of position-tracking data to an online database for easy access and mapping. In this case, GPS telemetry data is used to track latitude, longitude, altitude, course, speed, and time measurements in near real-time via

Although this reminds us of the WhereAVR that we covered previously, the Trackuino includes an onboard radio so no external handheld unit is necessary. Since the Trackuino was designed primarily for high-altitude balloon tracking, a number of useful related features are also included: dual temperature sensors, support for a humidity sensor, and a remote “cut-down” trigger really make this a complete package.

Initially there was some concern that the 300mW radio used would not be powerful enough to reach the ground-based receivers from peak altitudes. This was clearly not an issue however, as the signal was heard from nearly 600Km away during the maiden voyage. If this still doesn’t sound like enough power, a 500mW radio is also supported.

Make sure to check out [Javier]’s blog for some amazing high-altitude photos and everything needed to get your own Trackuino up and running in no time!

Thanks [Brad]!

31 thoughts on “Trackuino – An Open Source Arduino APRS Tracker

  1. After googling for the project, and reading the data sheet for the module, I’m not so sure about this. I’m happy they’re getting results, but I don’t think the TXD line on the module is really meant to be PWM’d. I’m concerned that there would be “splattering” on adjacent channels using this method.

  2. @trialex

    Seriously, John is right. If you can even follow along with these projects, you could pass with no problem. We need more hackers in Ham. There are far too many retirees with too much money polluting the hobby. ;p

  3. If you’re not licensed, you could replace the radiometrix module with another for one of the unlicensed bands for whatever country your in.

    In Australia at least, the foundation license only allows you to transmit voice. For data you need a standard license which is much more difficult to get.

  4. @hpux735
    We tested it with a spectrum analyzer and it is well within acceptable limits.
    The HX1 is made to have TTL input. It then converts the serial to a FSK RF output.

    So the HX1 ONLY does FSK data. We are working on software FSK so that it could be used with another radio utilizing the mic input.

  5. Thanks for all the licence comments. I’m in Australia – this is what the regulators website says: “Just complete a training course with as little as 20 hours training and at the end of the course a 50 question multiple choice examination, a multiple choice regulations examination and if you do not hold a foundation licence, practical test and a few days later yours on the air with your new standard grade licence.”

    The cost for each of the three exams is $70. For my balloon project I just put a message on a local HAM message board and teamed up with someone who was interested.

    Any no license required similar equipment?

  6. @Kyle

    I should mention I only ask questions in such a direct way when I’m really seriously considering using something. I wrote code for the ATMega that did AFSK bell 202 1200 baud modulation. I got stopped dead in my tracks when it came to AX.25. I’m really happy that you wrote or found all that code. It is very likely that I’ll port it to C. (Down with C++ !! :) ) Nice project, b.t.w. I’ll send you a link if I do anything with it. I’ve got a few old 2 meter handheld transceivers that have been waiting for this. It’s all about 5 Watts of power!!

  7. I just happened to be bored at work today and started working on a fairly detailed simulation of a high altitude balloon system (ascent rate, thermal transfer from the capsule, etc), I come home and what do I see? The practice to my theory, good timing.

    This project is really everything I could want. I’ve always been put off by some of the closed source, expensive components necessary (I’m looking at you TNC).

    I’ve wanted to do high altitude ballooning for years now ever since I first saw the autonomous glider project here on HaD:
    That incidentally was the first post I ever read on HaD (4 months after the blog started!) and has kept me coming back everyday since.

    We had a HAB project at my university that almost got off the ground (zing!), but alas the project leader graduated.

  8. We’re starting to ship our new RTrak-HAB (High Altitude Balloon) tracker this week. The HAB is based around the open source OpenTracker 1+ firmware and has a 350 mW, fully programmable VHF/2M transmitter module, good for 144-148 MHz. We also have 5 ADC channels for telemetry and 4 general purpose outputs for controlling devices like a digital camera. See more details and photos at:

  9. @Kyle

    We worked closely with the BEAR group in Canada to make sure our tracker was exactly what the HAB groups were looking for. One thing the BEAR group found was the Radiometrix module was prone to bad drift in cold environments. The MX146LV module that we used on our tracker has an on-board temp sensor used for compensation and keeps it from drifting. The result is a rock solid transmitter for just about any temp range. Our ground based RTrak trackers use these as well and we know of people that leave them in cars all of the time, in all kind of cold and hot weather. They keep going and stay on frequency.

  10. @hpux735

    Well the AFSK magic is in the HX1. And the AX.25 is just the format of the serial data sent to it. So you can just send serial strings in the APRS format to the HX1.
    Javier is the guy to talk to about the specifics of that though.

  11. I had a very surreal moment when I went to

    It was showing me my street just a few hundred meters from my house. It took me a few moments to realize it was not tracking me and it was just someone participating in the project cruising down my street.

  12. If you don’t limit yourself to AX.25 (a particularly inefficient protocol which APRS is built on) you can actually get similar distances with much lower power. Over 500km has been achieved with only 10mw of power using the NTX2, the little brother of the module used here.

  13. I agree with Phil. 300mW only going 600KM with the transmitter at altitude? The antenna must be seriously mis-tuned; I can get 100KM from ground level at that power with just a longwire.

  14. Which radio receiver was used on the balloon for the remote cut-down mechanism mentioned in the summary? I’d like to implement a remote cut-down mechanism myself, I can’t seem to find any details on that on any of the linked pages.

    Thanks for clarifying this point.

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