Nine PsyLinks

Recently I've been assembling some PsyLinks for anyone who is curious to try it out:

It was a huge help that the SMD parts were already soldered on by PCBWay. These were partially sponsored by PCBWay, which I am very grateful for. The quality is perfect, couldn't have done it better myself.

You can't imagine how happy I am for not having to hand-solder the tiny SC-70 voltage booster (2mm x 2mm) anymore! I also appreciate that PCBWay left no break-off points on the sides of the PCBs, since they tend to scratch the skin and I usually have to file them off manually.

I still can't outsource the assembly of through-hole components since I manually have to cut the connectors short enough so the bottom side doesn't scratch the skin. But I hope some day I can fully outsource the assembly and can focus on research and development instead.

Of the 9 PsyLinks on the photo, 4 are already reserved, but feel free to ask for one if you are interested!

Android: First Step

The new PsyLink GUI now builds on Android!

One part is still missing: Bluetooth connections. So, currently the app is effectively useless, as it will scan for PsyLink devices but never find any. A good first step though.

You can find the Android build instructions in the BUILDING.md. It's quite the wrestling match.

Rev2 Firmware

The PsyLink Arduino firmware now officially supports revision 2 ("Rev2") of the Arduino Nano 33 BLE (Sense).

You can toggle between Rev1 and Rev2 by setting the variable ARDUINO_REV2 to true or false.

Prototype Fund

I almost can't believe it, but this project is receiving a grant from the Prototype Fund!

The funding goal is to build new software for the PsyLink that runs platform-independent and user-friendly, as one of the major issues with PsyLink so far is how hard it is to set up the software. The current software uses Python and is Linux-only, and users have either written their own front end software or gave up trying to use it entirely. I plan to fix this with a Rust reimplementation that will run on Linux, Windows and Android.

This is what the new software looks like so far:

In contrast to the previous software, this is just a double-click on a single binary file, with no dependencies and no necessary user interaction - it automatically finds the PsyLink over bluetooth and connects to it.

The plan is to finish this in September and give a demo in Berlin.

Prototype Fund is looking for more applicants every 6 months, and I can wholeheartedly recommend them. The people are wonderful and it's been a great experience so far. Give it a try too, if you're based in Germany and your project fits the requirements. For reference, here is my own application:

My own Prototype Fund application (in German) can be found here as a reference.

Data Sheets

After learning about the 4-document-model (permalink), an insightful guide to writing better documentation for software projects, I realized that PsyLink really suffers from having its documentation so spread-out among the dozens of pages with no clear reference page that contains it all.

As a first step to mitigate this, I wrote extensive data sheets for the power module and the electrode module, bundled right along with their source in the schematics folder. You can find them here:

• Power Module
• Electrode Module

Hopefully this will help you to get the most out of the boards and reduce the mistakes you do while replicating or using them!