V-ARC (Violin Audio Regulation and Control

This is the last post before I submit for funding, so here is an additional description of what V-ARC actually is. I’m also including the pictures again.

Progress update:

I finished all of the details for costs, fixed an issue with the footprint for the 1/4” jacks on the PCB, and made an overview on the GitHub page

What is V-ARC?

V-ARC is a multi-effects pedal, preamp, ble page turner, and looper designed for electric violin. It can also be used for other electric instruments such as guitar. It runs on 2 separate controllers and includes a Lipo battery. It will be capable of being wirelessly reprogrammed for convienience, and should have an app later in development so that settings can be tweaked or effects swapped without interacting with it. It is also going to feature MIDI conversion and wireless playback in the future.

I made the firmware for both controllers. They should be able to communicate over UART. Here’s a code snippet since I’m required to have an image here. All I have left before submitting my funding request is to add details to the GitHub repo and get a cost breakdown/BOM.

I finished the PCB. It has a nice ground zone setup so the analog and digital grounds get mixed near the power where the noise shouldn’t cause issues. Here’s some pictures of the PCB finished.

I finished laying out the PCB and added some ground zones for both analog and digital grounds. These will make up the majority of layer two, except where I need to make vias for crossing other traces and where I have THT components. I started wiring, but I have only just begun that part.

I made a few small changes, including making the input jack have a switch to prevent noise if not plugged in. I also remembered to send the final image this time. Anyway, I did footprint assignment and have now started to lay out the PCB, but I’ll be routing once that’s done. I have to be careful since this is a 2-layer PCB and I have to make one layer almost entirely 2 ground planes. But progress shall be made.

So I finished the schematic by adding the Xiao ESP32-S3 side of the design, which will control the wireless capabilities such as the built in page-turner and should later allow for reflashing or editing the Daisy Seed 3 board wirelessly. I also took awhile to organize all the sheets in the schematic to make it easier to reference and debug if I find errors (and for anyone else that may make one of these or design software for it. Once I do a few more checks it’ll be onto PCB design.
Edit: I missed the picture of the new section, but Stardance doesn’t allow adding more files, so I’ll add it in the next devlog I guess.

I made the audio front end sheet which will allow it to take in the audio from the violin and amplify it before processing the other effects and such. I also updated the name. Then, I made the sheet for the audio core, which uses a daisy seed 3 board and a whole lot of switches. Here’s some pictures of the progress

Ok, so I’ve been playing violin for around 8 years now, and I finally decided to get a 5-string electric one. However, I find that preamps and effect pedals, especially ones actually intended for violin, are rather expensive. The same is true of page turner pedals. So my goal here is to design one that is far cheaper, has more features, and can be customized. I also wanted to implement a wireless page turner and power it with a rechargeable battery. So to start, I made a power management sheet. It takes in USB-C power, charges a 3000 mAh battery, and converts it to a +5V, +9V, and -9V.