A package from PCBWay with a new version of uECGs just dropped! Or rather was brought by DHL courier, which deliver better and better by the shipment - previously we shied away from them, because there were too much red tape and they were arrogant, but maybe they're not so bad after all. 
Anyway, there were three uECG versions before this one:
- the v1.0, made back in December, 2018, which required some wires to work and had ECG snap connectors salvaged from Chinese cheap wired electrodes bought at a taobao acupuncture shop. We found a shop that sold snap connectors after that, which was a great adventure that took some weeks, but we learned some Chinese words along the way.
- the working v2.2 - most featured in videos and tests
- black one, the v3.1 - we had experimented with halvanic skin measurement there, but that didn't work so well. We also planned to add vibe motors to make a gamer feedback device - maybe still do that later.
- and now the new v4 had all bugs fixed (thanks to hackaday commenters for pointing out some of those!): analog and digital ground is properly connected now, and it also has protection in form of a resettable fuse and a BAV99.

We'll assemble them in a couple days and see if they work well.

The second PCB is a multi-protocol base with 16 LEDs and a lot of IOs. It's like LilyPad, but based on nRF52832. We plan to use it a lot.