With my electronic harp mandolin project I've been enjoying working with analog and embedded audio hardware. And a few weeks ago, after reading about Ugo Conti's whistle-controlled synth I wrote to him, he gave me a call, and we had a really interesting conversation. And my existing combination of hardware for my whistle synth [1] is bulky and expensive. Which has me excited about a new project: I'd like to make an embedded version.

Yesterday I got started on the first component: getting audio into the microcontroller. I want to start with a standard dynamic mic, so I can keep using the same mic for talkbox and whistle synth, so it should take standard balanced audio on XLR as input. In a full version this would need an XLR port, but for now I can pull back the housing on an XLR cable:

While I'm not really at a clear stopping point, I wanted to write up my recent progress with the electronic harp mandolin project. If I go too much further without writing anything up I'm going to start forgetting things. First, a demo:

Or, if you're prefer a different model:

Since last time, I:

• Fixed my interference issues by:

  1. Grounding the piezo input instead of putting it at +1.65v.
  2. Shielding my longer wires.
  3. Soldering my ground and power pins that I'd missed initially (!!)

• Got the software working reasonably reliably.

• Designed and 3D printed a case, with lots of help from my MAS.837 TA, Lancelot.

  

• Dumped epoxy all over the back of the metal plate to make it less likely the little piezo wires will break off.

  

• Revived the Mac version of my MIDI mapper and made a cut down version that is designed to drive a wind instrument synth (code).

While this works, it's a little bulky for attaching to the mandolin. I also don't like having a bunch of wires running from the teeth to the computer and that I only have thirteen of the eighteen inputs hooked up. I've also been enjoying playing it with my fingers, in more of a piano orientation. I decided to make a new version that's all a single board:

The squares show where the "teeth" will go.

I've prepared a new batch of eighteen pluck sensors:

Sanding them smooth was a good fit for watching the kids at the park.

I'm a bit nervous with this design that something will break and it will be hard to repair because it's all on one board, but it's got to be better than the giant blob of epoxy in the v1 design.

If this works well I might make a case for it where only the teeth poke out?

Tomorrow, Lily and I will be leading a Kids Contra Jam at NEFFA (2pm in the Sudbury room!). We'll be playing off of Lily's tune list, but someone was asking about chords. I decided to have a go at writing out the simplest acceptable chords for each of the tunes we're planning. Each letter represents two downbeats:

A friend asked whether anyone else had noticed a pattern where big contra dance events were generally booking more established callers since restarting. This could make a lot of sense: the established callers will be less "overplayed" than they had been, and many events will be less robust financially and so more risk averse. Can we use the trycontra.com/events data to see if this is happening?

In 2020 I renovated the small building in our backyard which had fallen into disrepair. It was zoned for use as a home office, and had electric but not plumbing. I wrote about how I was thinking about insulating it and comparing framing options but then apparently I never got around to writing up how I finished it!

I'm generally a pretty big fan of transparency, and one way I try to promote this is writing up our finances every few years (2022, 2020, 2018, 2016, 2014). This is also useful to me: putting things into a form where others can understand it is pretty good for getting myself to really understand it!

This post uses the same approach as last year, which is almost the same as before then. Numbers are monthly, based on 2023 spending: