Awesome to see HAB on hacker news! Was following some of your development years ago when I developed a small APRS tracker, have been meaning to revisit that project someday. Also developed a WSPR version that I haven't published any info on, but had a great trans-atlantic flight with that one. Keep up the great work!
http://protofusion.org/wordpress/2015/10/featherhab-2-gram-h...
http://protofusion.org/wordpress/2016/02/featherhab-source-c...
I did one of these balloon launches myself several years ago, and attempted to build a flight computer myself with Arduino and multiple sensors. I could not find an efficient way to read all of the data from the selection of sensors in the limited memory, so I wound up using a Mega. Nobody involved was a licensed radio operator, so our live tracking was very primitive. It wasn't until after 45k' that we realized our GPS tracking stopped tracking at that altitude because why would a civilian be at that altitude. Of course we didn't know that until researching it after recovery, but we were very relieved when it started to updating once it came back under 45k'. Unfortunately, something happened (my coding to be sure) that caused the log to not be written as expected. Was hoping to be able to compare the GPS of the actual flight against the forecast model we used. This is the very thing I would have loved to have for future launches. I even made friends with a licensed operator to make it legit. (couldn't be bothered to take the test myself)
One thing to keep in mind for anyone wanting to do their first one. If you go to the trouble of printing up contact info for an "If Found", don't forget to attach it before lift off like I did.
Interesting!
I'm thinking of building a small PCB for ballooning too.
But I most likely will shift the design decisions a bit:
- 2.4GHz LoRa for high-rate telemetry as reciving can recycle Wifi-Antenna gear. The Semtech SX128x chips are easy to handle.
- Low rate telemetry on 433MHz with a SX12xx or SX17xx.
In terms of chips most likely something around the STM32U series.
The company ePeas has very interesting energy harvesters. Not super cheap - but still affordable. They have special profiles for supercaps which are very resistant against freezing.
You should check out Sceye, they're hiring and doing this. Unfortunately you have to live in the middle of the desert in New Mexico, otherwise it's a cool company
looks like a bunch of NEWBS.
(guessing github.com/NEWBS was taken)
Love this. Have a friend that regularly sends $30 balloons a few times around the world. They routinely end up over interesting areas like hot spots in the Middle East or North Korea. Would be great to issue commands to a light weight camera but the bandwidth is so limited - payload is a factor too - can only be under 100 grams or so. Bandwidth is in the order of 30 bytes per minute. Would be fun to take picture remotely and then drop the payload/memory card when the balloon circled back to friendlier territory.