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2023-02-21 - Tech - Compy - Raspad Fun (a todo list)

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This is a short post on where my Raspad (Raspberry Pi tablet) tinkering has gotten. The past week I’ve cleared out a few cobwebs off my todo list. But there is always more to be done. I don’t know if one can justly state that the Raspad is the Volkswagen of tablet computing. But it is certainly more flexible than any I’ve seen, both in hardware and soft. The downside to this has been the necessity to get my hands dirty with compiling source code. This is not really a bad thing… unless I can’t figure it out. Lately I’ve been muddling through.

I’ve hit a small wall on certain seemingly obvious and basic interface issues. I have Touchégg running, but not the gui Touché. (Or is that vice versy?) The most annoying of these include the edge mismatch on the touch screen. I’ve recalibrated X, but it still won’t correct on that outer 5mm or so. Likewise, the lack of decent CJK handwriting IME in Linux land is bizarre. The only one which isn’t a moribund project uses Google servers, and so that is entirely not on.

CPU frequency scaling (over/underclocking) is a basic need of all mobile devices. The Linux management in this is scattershot and needlessly obtuse. Just compare the config.txt ecology of Raspbian to Ubuntu Mate for Pi if you don’t believe me. Really, cpu freq scaling is a victim of the Unix paradigm downsides. Despite pitching it on a few GitHub projects, no one skilled seems interested to solve this, so I shall have to DIY it. I’ve done that a wee bit using aliases, but this doesn’t do for quotidian use. A panel widget to adjust cpu_freq is needed, and behind it a new governor which will throttle the chip down to 200kcs or so on idle.

For these gripes, I am much happier with Raspbian than I was, and LXDE. I’ve puffed up and better spaced quite a few icon buttons. Now and then I even note a “tablet mode” some kind dev has installed in their windowed programmes, for which I’m ever so thankful. I am using both evdev “long tap” and Touchégg “two finger tap” for right click. Both are handy in different contexts. When properly set, they are organic enough.

I’m even more pleased with how well Guake works in a tablet. It makes *nix computing on a tablet natural, when coupled with OnBoard. Windowshades are a sorely underdeployed interface for tablets, really. I’d like more such things, perhaps by customizing Guake’s boot, thunking Emacs toys in. Right now it doesn’t keep state across power cycles, for some reason, and no one can tell me why. It should be scriptable to pop up terminal doohickeys in anacron or whatever.

One of the signal virtues of a tablet is in a direct art programme. I have precious little skill in visual art. So I find a tablet quite forgiving compared with paper. One deficiency is for brush art, which one might think easy to fix. But all the capacitive brushes I’ve found, and there aren’t many, are splayed out western style brushes. There seems to be no real workalike for a traditional Chinese brush. The stylus-plus-soft-brushes are emphatically a chintzy kludge. Perhaps this cannot (or should not) be fixed. But for all the times I’ve spider smudged a character or misplaced a stroke in an otherwise painstaking formal letter, I surely wish I could find a way to truly handwrite on tablet. Oh, to press the ↪️ redo key on paper!

My hope for Raspad is that the components are of durable quality enough to last a decade or so. The 4B motherboard and io daughter board at least seem durable. Two decades are even better. One last infoprosthetic to rule them all. Before too long, “temporary” supply chain woes are likely to become permanent anyway. Best to be ahead of that curve a few paces.

Raspad Hopes - Near Term

Transition to Raspad as primary carried device by midsummer.

Dependencies

Fix the ruddy styling and interface once and for all. Duplo block all buttons. Some programmes still refuse to obey my gtk & qt styles. Why? No one seems to know, so far. But someone somewhere does. Likewise obliterate all remaining drag-drop and pinching nuisances. (Why enable pinch zoom at the same time as two finger scroll? What cocksure athlete uses these contrary idioms?)

Tangentially, finish the custom Onboard SVG keyboards. A split keyboard for emulated games too, now that it is tenable. Fix the login keyboard, apparently made solely for smartphones. Make OnBoard language modes for the major (and fave but not so major) Chinese IME layouts - Rime Nanking pinyin, intelligent pinyin, shuangyin, Rime pinyin+, traditional wubi + pinyin, stroke + pinyin, Jyutping, Cangjie.

Set RTC away from the Pi 4B, on a secondary i2c address, so the first can be used for the accelerometer again.

A buckboost converter to maximize solar power efficiency. 15v is deuce awkward for a 12v bus aficionada, chaps.

Cooling - a better fan, possibly controlled by GPIO pwm. At least install the pesky hard switch.

A better panel widget for cpu frequency scaling, with a custom deep-slow clock on idle governor. This I must likely DIY, it seems.

Finish Nextcloud integration (armhf tools rot here). I’ve made progress on this front recently. I need some town time for a fast broadband migration. We still wait on snows for that.

A cute protector case. Handles, strap anchor loops, and/or MOLLE. A pocket for the Bluetooth keyboard. I can sew it, and have batting for quilting, but still need some rubbery sheet plastic for the clamppy bumpers. Maybe I ought to just 3D print something to protect the screen.

An ergonomic home keyboard. Some old usb junk. But it should be split and have a trackpad.

Get 中日韓越壯 handwriting working. Google handwriting IME, but consults Zinnia. Probably a deep diy. Capacitive brush?

Raspad By and By - Long Term

HackRF - case, antennas, balun to 300ohm, linear PA and LPF for select bands.

Chassis ground screws and ferrite beads.

A small radio built in. Tx? For VHF/UHF packet. The guts of a used UV9r might do.

Set up straight key and programmes for CW, somehow.

Enlarge battery bank - just add some more 18650’s in parallel?

A flip-out, 90° turntable “noir” camera. Cheap on Adafruit.

Inset a full GPIO pin access breadboard type panel.

Copper foil shielding. Outside for antiseptic and durability?

Spring loaded splined joints. 3D print to fit - Aluminium tubing. Flat, high tension springs. SS bolts &c.

A rotating upside down base.

Integrate with the boost converter line.

USB-C power?

A clean micro UPS?

A tactical foldout solar panel.

A Mingkuai IME for Rime! A “full luxury” custom handwriting IME for Rime! Transition away from slovenly pinyin.

Full uxn suite for programming learning. Get back to Lisp and WYLang projects long term.

Emacs in windowshade.

An electronic stylus and softtoys. Apple Pencil? Real brushes?

Spare parts for backups. Can use Orange Pi &c. for motherboard?

Low power alternative motherboard. PotatoOS? Puppy? Plan9?

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