Trying out Gnu plus Linux on the desktop again. First search result about my first problem is an angry forum dweller chastising a first time poster for not using the search function. I am using "EndeavourOs" which advertises that one is its main benefits is a "friendly community".
It really expects you too test it with a midi-to-usb-to-mini-usb configuration, but i have no such big-to-mini usb adapter, so the plan is to send midi the traditional way
Unsurprisingly, it's not coming to life on the first attempt. I never worked with midi signals or opto-isolators before, but i can tell there's no signal on the scope.
(Yes I'm using a circuit by a fedi mutual. no I'm not crediting with a mention yet lest they think I'm asking for tech support lol. I need to be way more out of options than this before i ask for help)
So, it turns out the keytar i was using wasn't sending any MIDI. In fact i couldn't get it to work with some other gear such as a volca.
I think it's expecting a greater load than my circuit to start sending anything on the MIDI out.
I swapped to another keyboard (some of you nerds will immediately recognize it) and this one does send MIDI! You can see the messages on the scope.
Still not getting the opto-isolator circuit to work yet, but that's progress.
Remaking the opto-isolator MIDI in circuit, i'm convinced I'm sending proper MIDI. It's hard to diagnose what's going wrong. Maybe the DAC is not working, maybe it's not acknowledging the data.
Once i received a F<>F USB adapter it will be easier to test it as intended, using MIDI USB.
I received these 2 adapters this week, they should help me get the project unstuck.
The F-F USB adapter lets me connect a USB MIDI device without having to splice a cable, while the HDMI to mini-HDMI adapter will let me connect a display with speakers
So far, it looks like it can recognize the USB MIDI adapter.... But that's all i have for now.
Got the MiniDexed to work partially! With USB MIDI and HDMI sound outputs, it emits sound, but with a considerable delay (seems about 150ms). So that means i had something wrong with the DAC.
This will also allow me to check that my MIDI in circuit works properly later.
Not sure how I can embed peertube videos properly in Akkoma, it's weird, if I repost the post from peertube it embeds correctly on akkoma, if i look at the previous post in this thread from a mastodon install it embeds properly, but on akkoma a link to a peertube page won´t embed the vid.
Ah, with that excitement, I forgot one more step.... I need a power circuit, I can't power it from USB once in the synth. Pretty simple matter to rig up of course.
I had to shuffle the components around to make them fit, and my temperatures are still a bit too high. Sadly, i think for now this build will be USB only. I didn't estimate right what those little regulators can handle.
I entirely forgot that i have a few of those cheapo step down converters! They seem stable and consume less current.... Let's see if they stay stable for a few hours
Gonna be honest, while this was a nice build, it's not very useful in my rack without CV in, I don't really use MIDI, and I use keyboards to compose but don't have the skills to play them live.
The MiniDexed closed the feature request for CV In and suggests using CV to MIDI hardware, but it feels silly to my spending-averse ass: there's some unused GPIO pins, there's some processing power to spare, and reading a few values at control rates can't be that demanding on the CPU. I'll have to look into this.
