CBA Podcast

This time, we explore the wonderful world of being zapped by a high(ish) voltage electrolytic cap, some maze-generation algorithms in a nutshell, disassembling a simple step-counter, and starting a scootmobile with a magnet-key.

No idea how this episode got so long... Featured(tm): reselling my HP3455A DMM to the person I bought it from, a meeting of the HCC computer-club (.nl) Retro-section, reverse-engineering a overflow-valve for a laundry-machine, making quick electronics-prototypes by manually engraving copper-clad PCB, and making an enclosure for the DPS5005 power-supply module.

Links:

• the HCC computer-club (.nl) and their Retro-section
• Awesome Space in Utrecht (.nl)
• a video about quickly prototyping electronics by manual milling of copper-clad PCB
• DPS5005 power-supply module
• CSDb-entries for cartridge-adapter demos (click "Attract-screen for...")
• Hackalot hackerspace in Eindhoven (.nl)
• INDIGO indie-game event in Utrecht (.nl)
• IFComp interactive fiction competition

Here's the overflow-valve and a schematic:

...and the DPS5005 in its smudgy anti-theft enclosure:

Quite a long episode this time - hope it doesn't bore you too much. Topics include the ability to ask silly questions and do silly things, sharing a serial link to an AVR between programming and debugging without bootloader, the portable TS100 soldering-iron, interesting game-console candidates, and past and upcoming events.

Links:

• YouTube-video of old vs new Qibec CPU
• Miniware TS100 soldering-iron
• DPS5005 DC/DC power-supply module
• ASxxxx Cross Assemblers
• BASIC 10-liner contest
• HCC Computer Club: Retro-devision (NL, Dutch)
• INDIGO indie game festival (NL, Utrecht, June 29)

This episode talks about what happened to my RetroChallenge RC2018/04 project, software-development for yesterday's computers, the last Hackalot-meeting, components with crappy documentation, disassembling a toaster with actual electronics inside, and the usefulness of various engineering-tools found in my workplace.

Links:

• Hackalot - upcoming hackerspace in Eindhoven (NL)
• the RetroChallenge-event...
• ...and my project for that
• fancy JBC CLMS-A soldering tip cleaner

This episode wraps up my (hobby)work for the RetroChallenge 2018/04, and talks about a favourite scripting-language or the lack thereof, the use of SD-cards, finding a new pet (or PET..?) homecomputer/console, and NE555-sound.

Relevant links:

• RetroChallenge
• ...and my Bait-a-Cart project for that
• ...and some videos of that project (YT playlist)
• Electromagnetic Field camp
• Outline demo-party

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The hot-glued Bait-a-Cart adapter at the end of the project:

In action, displaying a C64-intro hosted on the cartridge-adapter's internal flash:

The NE555 sound-setup (schematic is literally 2 NE555s in cascade, used in astable mode straight from the datasheet):

Made it to episode 20, and it's still a lot of fun - I hope the feeling is mutual. :-)

Topics of interest: a bit of background about this podcast itself, playing around with a vintage Luctor N.V. Multiset AC power-supply, last weeks' effort for the RetroChallenge 2018/04, disassembling a coffee-machine and the upcoming Vintage Computer Festival Europe (VCFe).

Relevant links:

• upcoming Hackalot hackerspace in Eindhoven (NL)
• RetroChallenge 2018, April (RC2018/04)...
• ...and my project for that
• Vintage Computer Festival Europe (VCFe), Muenchen

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RC2018/04 project status, showing C64, Bait-a-Cart cartridge-adapter and existing ROM-cartridge in action, along with the small 2nd hand TV:

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The Luctor N.V. Multiset AC power-supply:

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Pics of the coffee-machine's thermostat before and after destruction:

(First of all, apologies for the many "uhhh"s and "ummm"s you can hear - no idea what was going on there. Edited out a lot, and next time it should be better.)

Topics this time are my effort so far for the RetroChallenge 2018/04 (25% in), a short and biased discussion of some available handheld oscilloscopes, disassembling consumer-scales to see what was going on inside, hacking together a small digital probe to distinguish high/low/floating pins, and blowing a fuse while poking at electronics.

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Links/show-notes, in that order:

• my effort this week for the RetroChallenge 2018/04 (April)
• some portable scopes:
  • the ones I used:
    • Velleman HPS140i (1-channel)
    • Velleman WFS210 (WiFi, 2-channel)
    • Seeedstudio DSO Nano v1 (1-channel)
  • nice but starting from approx EUR 400:
    • Owon HDS series
    • Micsig tBook series
    • Siglent SHS series
  • PC-based:
    • Owon VDS series
    • LabNation SmartScope (software any good..?)
• Awesome Space retro-place (Utrecht, NL)
• Makersbase fablab (Breda, NL)
• Hackalot hackspace (Eindhoven, NL)

W.r.t the blown fuse: I made the rookie mistake of connecting probe-ground to something main-referenced (but not earth)... #makeagoodfirstimpression

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Some pics of scales-disassembly:

(load-sensor mounted in one of the scales' 4 feet)

(strain-gauge element (?) embedded in metal spring-thing)

Note that when the metal thing is flexed, both "halves" of the element would decrease in resistance - a few hundred Ohms when flexing them by hand. That's why I don't understand why there were 3 wires bonded to this thing. Why not use 2? (From what I read and discussed with a friend, one "half" would ideally have to have a constant or at least less-decreasing-when-flexed resistance, to be used in a Wheatstone bridge.)

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Schematic and pics of the digital probe:

(probe in a blob of hot-glue)

This episode covers one more PCB-failure (see previous episode for more fail), a LED that would still emit light at a rediculously low current, shortcomings of DIY lasercut stencils from a previous episode, my entry for the upcoming IFComp, disassembly of an old bread-toaster, the RC2018/04 Retro Challenge which will start tomorrow, and some more upcoming events.

• IFComp - Interactive Fiction Competition
• Retro Challenge RC2018/04 in April...
• ...and my entry for the RC2018/04
• Outline demo-party (10-13 May)
• Hackalot: upcoming hackerspace in NL

For the upcoming IFComp, I want to make an interactive cassette-tape, where the tape-reel is replaced by software driving a magnetic element to emit sound/speech, where the user interacts with the game by pressing fast-forward/rewind/play/stop on the tape-player.

The project will thus consist of a reworked cassette-tape adapter (fitted with electronics) implementing an adventure-game. Let's create the actual game within the IFComp contest-period, and make the hardware-platform in advance - as in, now.

Reed-switches and magnet forming a simple encoder, and the magnetic element to emit audio towards the tape-player's head:

Testing the tape inside a pretty tape-player:

Signals from both reeds-switches. By observing delays, frequency and phase-shift, the software can process game-input:

Tetris'ing electrical components within the tape's enclosure:

Testing the toaster. Cold-spray, stopwatch and 2 thermocouples:

The actual "circuit". No idea what the pink wire was for. "M" is the heater specifically for the bimetallic strip, and "H" is the main bread-heater:

Only a short time between the last episode and this one, so I didn't do a whole lot of stuff: spent 1 day volunteering at a local Home Computer Museum, decided on a project for the upcoming Retro Challenge 2018/04, went through all PCB-design I've ever made and made a list of common failures, and fixed a headphone with built-in microphone (that is, removed the microphone-part).

• HomeComputerMuseum (Helmond, NL)
• Retro Challenge 2018/04...
• ...and my entry for that
• IFcomp: interactive fiction competition

Here's a pic of the microphone/pushbutton thing on the mentioned headphone, with a circuit of what's actually going on:

(the cap is probably a 22 nF one though... Just blindly copied what the meter told me :-)

Maker Faire Ruhr (Dortmund, .de) came and went, so this is the last time you'll hear about my project for that - finally. Apart from that, this episode is about hot air soldering and upcoming events, local and remote, on- and offline.

• recent Maker Faire Ruhr (2018-03-10 & -11)
• IFcomp (submission for entries starts on June 1st)
• Retro Challenge (in April)
• HomeComputerMuseum (Helmond, .nl) opens on March 17th
• my Maker Faire entry: Qibec 1-bit 1-instruction transistor-CPU
• Hackalot hackerspace (Eindhoven, .nl)
• Electromagnetic Fields camp (Aug/Sept, England)
• Mithotronic's LEDmePlay game-platform
• Vintage Computer Festival Europe 19.0 (Muenchen, .de, end of April)

Some pics of my Maker Faire Ruhr project: