RE: High Altitude/Near Space Ballooning

shabaz — Thu, 04 Apr 2013 10:22:46 GMT

Hi,

It sounds fun. I've not seen the schematic (might want to post a jpg image to make it easier for people using mobile devices, etc).

Some comments:

GPS has a height restriction so you may need to rely on barometer if you get really high

Also, as a suggestion, you could also consider maybe just log to RAM or a local non-volatile storage, rather than transmit.

For tracking, an option which doesn't require you to spend time/effort constructing a receiver is to just transmit via radio just morse code of the GPS co-ords for you to record and play a few times to manually interpret, which is feasible even if you don't know morse code. Or, I'm sure there must be free software to do this decoding if you plug the audio from the radio into a laptop (might affect your radio reception though).

You could transmit just occasionally for you to estimate the direction, and transmit more frequently as it descends maybe - I don't know what the flight profile of a balloon is ; )

Edit: Sorry, just ready your post in a little more detail. I think there are some arduino libraries for writing to an SD card, so you should be ok. Your code doesn't need to write in .csv format, since you can post-process the data on your PC. Beware that temperatures will be very extreme, so ensure you're using reliable connectors, a suitable battery, etc. There must already be good forums on ballooning with this type of information I guess. Keep the code simple so that even if nothing else works (e.g. card writes fail or the GPS module or some sensor doesn't respond), at least it can transmit beeps when descending.