Hi all! This is my first project log on Hackaday.

This project, Canta-Cart, is a card-sized musical instrument with touch keys — to be an entry to the Business Card Challenge. It comprises 10 keys that make sounds of a diatonic major scale (spanning a tenth interval) and 2 transpose buttons for accidentals and overall transposition.

The design of the electronics has been completed. While they are on their way from the factory/warehouses, I have implemented a simulator on the desktop computer (also ported to the web browser) as a testbed for synthesiser and interaction design. It worked out quite well — tunes can be spelt out without friction on this keyboard; harmonics and musical textures are achievable, especially on the smartphone touchscreen, which is free from the limitation of key conflicts.

This simulator is now live at https://ayuusweetfish.github.io/Canta-Cart/synth/. It supports touchscreens and computer keyboards and has help information built-in.

Meanwhile, I've also looked into how the PY32F003 microcontroller works. This is selected in favour of my go-to STM32G0 in order to reduce the overall cost — at 1 Chinese yuan (US 15¢) it brings the entire device even closer to a business card to give away lots of. Resource material on it does not seem abundant, but after a bit of scouring I managed to put together a minimal, stripped-down LED-blinking firmware project. It compiles, but I'll have to wait until the components arrive to test whether I've got anything off-track.

The circuit board and the components are expected to arrive tomorrow, after which I will get down to the workbench to assemble the parts. Let's look forward to it.