HAB Payload tracker

[Nick McCloud]

Tony is about to be the lucky recipient of a parcel with a loan Pi-in-the-Sky kit, pigtails to turn in to aerials and a receiver board so you can setup a LoRa tracker.

Pretty much everything you need to know to get this going can be found here:

http://www.pi-in-the-sky.com/index.php?id=support

http://www.pi-in-the-sky.com/data/uploads/pits-manual.pdf

In software terms it's pretty bomb proof - at worst you'll just learn ways not to do things with software.

Hardware wise, please be careful about battery polarity - please put the battery snap on the battery holder before plugging it in to the board - just in case the battery snap is offered up the wrong way round - can & does happen. I've several melted battery packs from students short circuiting the wired ends of the battery connector! And due to a misunderstanding about polarity input protection and being rather tired, I recently blew up a Pi 3 and a £45 motor controller board, so happens to all of us.

Pretty much any Raspberry Pi 2 or 3 will be fine to get started. To fly, we will use a Pi A to save battery life. You can also use a Pi 2 or 3 for the LoRa receiver. Any Pi camera will be fine for testing but we have to fly a real genuine Pi camera as the Chinese ones tend to crash the GPS components.

Feel free to give up early on getting test flight documents setup on http://habhub.org and ask questions.

I'm sure the museum will help with the pigtail aerials. You'll need two, one for the RTTY, one for LoRa. The radio heads will want to do a full monty aerial with ground plane - which will be a total bugger to get on to the payload box and will not be happening on this flight but feel free to be shown how to make the ooh shiny spring wire eye pokers - I've a couple - they are fab but not practical on the small payload you are flying. Simply cut the pigtails (very accurately) to the correct length (measure twice, cut once). I get about 100km range out of them.

Instructions for setting up a Pi based LoRa tracker can be found here; http://www.pi-in-the-sky.com/index.php?id=making-a-lora-tracker.  You'll need to borrow an external aerial (or get another pigtail). There are some wrinkles in getting the auto-tune to work - so if it doesn't, I can provide guidance. To make them portable, I use a Pi Touch Screen and a really big battery pack. I've already got two portable trackers so you don't need to make them just yet.

For the RTTY, I use a handheld Yupiteru 7100 or 9000 with a rubber duck aerial for testing and an external mag mount on the chase - something that can receive 434MHz with Single Side Band - plus an audio cable to a laptop - use a low cost sound card USB dongle if it doesn't have sound in (most don't) and then enjoy the fun of tuning the radio and then getting the waterfall on dl-fldigi right - again, don't burn too much midnight oil going round the houses, ask away.

More to come on the physical payload - more pressingly, you'll need to choose a launch site where there is explicit permission to be there - one where the Police won't turn up with Glocks and Heckler & Koch MP5s due to the nutters with the big blue cylinder and the radio gear in a public space. Ideally, something with trees on the north-west corner (the prevailing wind in this country) and no trees downwind (south-east) for at least 2/300m to allow the balloon to get some height.