Balloon Based Satellite


This project provides an opportunity to conduct near space experiments. The flight computer, BalloonSat Extreme, is controlled by a BASIC Stamp 2pe. The complete BOM with PCB artwork is provided. There is enough hardware to control cameras, servos, a Gps, and five digital I/O. The computer is also equipped with a 12 bit ADC to log experiment results. The device seems limited to 30KB of storage. Though the author suggests this memory limitation is more than adequate, we are wondering if an implementation of the Nyquist sampling theorem is in use at all. For further reading the author has provided information regarding Amateur Radio High Altitude Ballooning.

[via adafruit]

14 thoughts on “Balloon Based Satellite

  1. hehe.. i am working on something like this.

    So far the plan is to have it relay back data optically via an RF based pointer (locks in on a local radio station)

    Ideally it would use a mobile phone camera with a bit banging routine to write the data directly to an SD card with one of those 512kbit RAM 8 pin chips featured a while back.
    Koff Saleae Logic /koff :)

  2. “we are wondering if an implementation of the Nyquist sampling theorem is in use at all.”

    I haven’t the faintest idea what you mean here. The balloon goes up, and then it hurtles back down. You only make measurements on the way up. Which frequency are you concerned about?

  3. “we are wondering if an implementation of the Nyquist sampling theorem is in use at all.”

    “we” are wondering if you’re sure you know what the nyquist sampling theorem actually means…

  4. That was snarkier than it had to be.

    But your sampling rate doesn’t have to correspond in any way to your data storage rate. If you’re sampling a thermistor, and need one second intervals, you could be free to sampling it at 250ksps (or whatever), and do an averaging on it.

    If you actually wanted to measure a frequency, then the nyquist thereom comes into play in terms of sampling rate. I doubt you’d want to simply capture the waveform though. it’d be much better to do an fft on it, and store the resultant amplitudes of the frequencies of interest.

  5. I agree the photo looks wrong but I don’t think it was to be misleading. It looks like the photo was taken from the side, then stretched to provide a more top-down perspective…. or something like that.

  6. “we are wondering if an implementation of the Nyquist sampling theorem is in use at all.”

    you do not know that every sampler has already the Nyquist sampling theorem built in.
    and that is free !

  7. The photo was resampled to 450×254. I could have cropped it but that would be lossy.

    About the sampling theorem, i was just hinting around that periodic events are likely to alias which would render some of the data useless. I probably should have said something about sampling EM wave shifting to clear that up a bit.

    Yes you could also do fourier transformation, if you have the cpu to back it up. In some cases you can cheat with power series approximations, if you don’t have enough cpu for hard realtime DFT/FFT and can justify a loss of precision /obviously based on the series terms/

    It can be hard getting some of the ideas across on the blog without diving deep in the prerequisites. Anyway the thing is based on a Basicstamp so we can’t expect too much from it other than control.

  8. Basically a single board computer tied to a balloon.

    A better, and get this, easier, implementation can be done with parallax propeller chips; you could even drastically reduce board space and cost by using them.

    A typical embedded CMOS camera censor is going to be useless for this without customized optics, and you can’t legally broadcast anything from it with out a high level ham license.

    I’d personally use it for Digital Radio Mondiale research or signal rebroadcasting. It might be good for amateur climate research too on a budget.

  9. The flight ocmputer isn’t all that heavy. It’s a concept board for larger and heavier BalloonSats. I have an article about in The Citizen Scientist. It permits several people/teams to design experiments and share a single airframe. The additional serial port allows a GPS to be connected so things like altitude data can be collected (something not often done on a BalloonSat mission). The image is taken at an angle and rescaled.

    There are other, smaller designs on my website (these are kits) for single experiment, single team BalloonSats. Check

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