Disclaimer: I got lazy^W late and didn't post this log on time. This log is dated 11st-12nd of June.

Hello! This is the first "work weekend" for ICeeData project. Today and tomorrow, I'm working on data demodulation.

This is also a small milestone. What's been ordered so far?

• Various RTL-SDR versions to make a small test of which is more and which is less suitable for our tasks, as well as to use for capture units.
• A couple of Raspberry Pi boards for assembling independent capture&decode units, first of which is going to be left at Estonia, with the base station of our participant. + various accessories for these.
• An EX1150 base station. To immediately be disassembled and hacked into. Shipping costs are a bitch, and I once again thank Hackaday Prize for this. I might order another one - as a spare in case my hardware hacking goes wrong.

What's to be ordered?

• A more powerful SDR. Frankly, I'm still overwhelmed with the possible options. HackRF One seems like a good match, but there are many other viable choices for the task. I'm quite curious about LimeSDR, for example - it might just be a much better choice since it's more capable and therefore should provide more for the future research. It's a crowdfunding campaign, though, and there's the problem - a small chance of being left without money.

As a starting point for working with data I've got, the transmissions I've got contain plenty of empty space. I'd need to remove that with some kind of a visual redactor. However, it doesn't seem to be that simple since all I know for this task is Audacity and it seems to not work well with raw data in the format I've got. What are the options?

1. Convert to WAV with a GNU/Radio workflow
2. Use some other visual editor

But first, let's greate a GitHub repo!

I'll try to go with the first approach. A quick google showed me a StackOverflow question which explained some details about the files I've got and the files I'd need.

Setting up Raspberry Pi. Installed: GNU/Radio, rtl-sdr tools, all the GNU/Radio plugins in the repo and Audacity.

To avoid permission problems, I added "pi" user to the "usrp" group created by something installed along GNU/Radio. After a logout and login, it worked beautifully, allowing me to use the "pi" user for GUI applications interacting with SDR hardware.

RTL-SDR I've recently bought seems to enumerate successfully. I could also see FFT of recorded files using this workflow.

Okay, time to convert files to WAVs! Here's the workflow I've made for this, as per StackOverflow suggestion. Then I cut them in Audacity and went on making a FSK decode routine. I've decided to look at the file FFT in Audacity. It didn't show any frequencies, showing a huge hill of frequencies instead. What the hell?

Let's look at the WAVs in Audacity:

What the fuck? Why does it look like crap?

Well... As per @geekskunk suggestion, my files might just suck. Unfortunately, this is a possibility. However, I've got SDRs now, and I'm receiving a base station this week, so I'll record more files. Also, I do definitely need one more base station. One I already have is to be disassembled and hacked into, another will be used for capturing new data for initial transmissions to make decoding algorithms and later for testing those.

I've also downloaded and compiled Inspectrum. A nice tool for analysis, though there are things to wish for.

These signals are strangely mirrored. Why so?

I intended to post this log on the Monday right after this, but had unrelated health problems which took a part of my energy. Therefore, it's only now that I post this. However, don't be disappointed, next log is about the base station teardown!