Arm, ex-Chromebooks and me

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 So, my sister had an Arm-powered Asus C201 Chromebook. This recently got de-supported by Google, it's no longer receiving any updates. It's light, the battery lasts 10h+ and still quite reasonably fast so it's a rubbish decision by Google.

Soooo, I've installed PrawnOS on an SD card. PrawnOS is a distribution for this hardware, runs on Debian 11 but it's got a custom kernel. The graphics card is well supported and works fast enough, (unlike some other Arm Debian distro I had tried) but the Wifi is an utter failure. The maintainer refuses to support the binary blob required. 

An old USB Dell docking station was borrowed from the office IT guy so that I can at least update and work on the thing. So far I've managed to get QSSTV and FLDigi working on it. FLDigi actually works quite well - all of this is plugged into the FT-818 via ttyUSB0 and a small £4 USB Soundcard that actually works very well. 

But JS8Call and WSJT-X refuse to detect any sound card, nor they print out a meaningful output. I haven't figured out how to put them into debug mode yet. I used to compile WSJT-X from scratch so I cloned the JS8Call repo and will check if I can build the thing with Pulse/alsa support. The problem is as follows.


Both packages are compiled for Linux, but no repository is available (which is a very weird choice in 2021). There are Intel 32 and 64 bit packages for Debian, and a pair of RaspPi OS ARM binaries. So I used the ARM binaries, but no. I'm confused because even on Raspberry Pi you'd need a USB sound card, so I'd expect that to work. I cannot figure out why else they are refusing to work. I've spent approx 30 mins on it so I guess I need to retry tomorrow.


Other than that, I managed to get FT-818 and FT-847 to talk to each other. There's something wrong with FT-847's data in/out - or my old cable is rubbish.I managed to dig out my old cables, and after much testing and frustration I managed to get the FT-847 work through the mic input and the headphone output. Not ideal, but it works. Then I dug out my USB to RS232 adapter, and also found a long RS232 cable, and started to use CAT w/o a fuss.


The audio side was a bit more interesting. Double-checking with an SDR, I can clearly see something is wrong with my audio when I'm using the mic input. When I was using the data input, the power level was completely inoperative, but from the mic input the power is effective. I've double-checked the manual and this doesn't make sense. 

Even with the minimum power, from a couple of metres away I could receive all sorts of digital mods w/o a problem. FLDigi works like a dream, QSSTV - not so much. I guess I should actually read the manual but I'm pretty sure I had solid QSSTV apps a decade ago, and I cannot figure out why I cannot find them anymore anywhere. Everyone goes "Oh, SSTV? Then QSSTV is the one".  if you ask me, it's overrated.


Anyway, I'll be making some new cables when the parts arrives, and by the time they are shipped and travelled from China to here I don't forget what the project was, I'm going to build a series of audio interfaces. I've ordered

  • USB to RS232 chips
  • octocouplers
  • audio transformer couplers - already have them
  • soldering platforms - got them
  • 2.5mm and 3.5mm audio sockets with multiple poles - got them but might have to order some more.
  • mic input socket for C5800
So, I'm thinking of making audio interfaces with RS232 PTT support using RTS for
  • A pair of FT-65s
  • Baefong UV-5R
  • Standard C5800
  • FT-847
Alright!

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