Because you didn’t have to look up in the printed documentation to find some useless explanation of everything except your actual problem.

Unlikely. The interference from the electric motor just worked because analog TVs used to recieve a (weak) analog signal via antenna. That doesn’t apply to the HDMI/RF connector. I suspect the CRT might not be able to deal with the HDMI converter’s line frequency. Also., I don’t know if the CRT has a separate composite input - if you go in via the antenna input be sure to set the converter to RF, not to composite output if possible. Composite and RF signal are not the same.

Little update: Got it soldered on rasterboard and integrated into my rack, powered by my pedalboard’s isolated ten line-PSU (thanks to individually settable voltages) and running as intended. Just to realize that I’ll need an option to send CC#28 (bypass on/off). I’ve implemented it as “both switches on” (I just had to rewrite the better part of the input routine for it - 2 bits representing D2 and D3 instead of clumsy if-then- else clauses) and am just about to take the whole thing apart to connect the SPI programmer. Might just drill another hole or better extend the ISP header to the outside for easier firmware upgrades- I am afraid that “simple two afternoons job” is about to become one of these projects unless I’ll stand strong against the persuasions of feature creep. If anyone is interested I can upload wiring diagram and code as soon as the last change is tested and working.

…shsh!

tap…Braiiiins!

OMG. Here we go again…

Yes. Exactly that. Had the Nano sitting around for years together with a couple of bare AVR MCs and an SPI programmer but didn’t do much with them because I just had no practical need. I was thinking of making a stand-alone USB host controller to turn some of my USB-MIDI controllers into standalone controllers with DIN connectors, but a Raspi and Yamaha UX-16 1x1 MIDI interface I had in the drawer and a ROLAND A15 that I hadn’t noticed would run as a full controller via DIN-5 when powered up without USB host did the job out-of-the-box. :-)

Actually belonged to a Raspi - I found it while looking for pulldown resistors and tried if it would still stick. Seems it did and I completely forgot it was there.