Insulation

Found this polystyrene box at work

It's probably a bit big for what we need, but it's nice and thick.

Unfortunately, I weighed it & it's a fraction under 300g - I think we are going to have to be careful of our all up weight!

RAMFly can sing ....

Well actually, more like tweet (like a bird, not like a teenager...) 

I spent way too long again last night, but eventually I got a basic radio telemetry setup working. I can now transmit information a massive 1.5m across my desk. That's without antenna and other required things which should boost the range to many Km.

Ramfly transmitting dummy data across my bench - click to expand

Here you can see my receiver collecting strings from the RFM22B. The second line has a receive fault (but the spelling mistake is all mine ... :) This was at 50 bps, 100+ proves very unreliable. However, remember there are no antenna though. The blue/yellow band at the bottom of the image is called the 'waterfall' and allows you to visualise non visual energy. Yellow/Red indicates energy and the darker parts silence. You can see here a 1200Hz sound and 1675 Hz sound. These are the sounds produced by the SDR radio in response to frequency shifts and corresponding Upper Side Band (USB) frequency compared with the reference frequency. The better the transmission the brighter/narrower the yellow/red bands will be. Although you can't see very well, there are two vertical red lines (directly beneath the red scale markers). These have to be very precisely aligned with the yellow/red waterfall marks to indicate the two frequencies produced by the payload. The horizontal blue band is the gap between two transmissions.

Wanna hear ramfly sing? 

The good chaps on freenode #highaltitude were very helpful. I was labouring under a misapprehension about how to set up dl-fldigi for a couple of hours - very frustrating

SDR

Well, that was harder than it ought to have been... Finally got the SDR working on my PC and (almost) on my laptop. The first problem was getting the SDR software, SDR#, to talk to the DVB-T dongle. Despite this being one of the approved ones, it still didn't want to play ball. Depending on where you look, there are a range of different recommended drivers...
Then it was extremely difficult to find a suitable variant (ahem) of the s/w needed to link the output of the SDR radio to the input of dl-fldigi. However, 4 hours later, I am now listening to Radio 1 on the most elaborate radio set-up you're likely to encounter... :)  
Time for bed I think...

Power

Figured we are going to need some battery packs, so I've ordered a few sizes:

9v clips
6 x AA
5 x AA
4 x AA
3 x AAA
2 x AAA

mostly like this from ebay:








All the arduinos seem to need 5v to run, but need 7-12v input voltage

might need to start adding up how much power we need vs weight of batteries

GPS log

Why cant I add pictures to a comment on a post?

Anyway, heres an hour or so of data collected from the GPS module
my house seems to be travelling a few knots, and hovering somewhere between 40 and 100 meters above sea level

GPS working

Looks like the GPS module working fine, (though not quite sure why my back window is doing 1.05 kts)
This one has its own ariel built onto the chip, and will also data log for around 16 hrs
Seems to work ok through the back window, so should be ok through a polystyrene box I reckon

output from Arduino:

Time: 13:48:4.0
Date: 1/3/2013
Fix: 1 quality: 1
Location: 5212.3139N, 0.3604E
Speed (knots): 1.05
Angle: 129.66
Altitude: 75.20
Satellites: 7


This was just using the stock Adafruit code, so we can strip it down & make sure the pins are correct for the payload

GPS - kit

GPS module turned up last night

Adafruit Ultimate GPS Breakout - 66 channel w/10 Hz updates - Version 3

plugged it into the breadboard by the arduino & now its time to start seeing if I can get it to work :)

The red pcb is a 3 axis compas module left over from the RAMboat project.  It might be useful to log direction of cameras on the balloon