The conference starts in two months, but by that time I need to already have several working and tested devices, so I really need to speed things up.

Since I won a coupon for laser-cutting in the Hackaday Prize, I ordered some parts for acrylic boxes to hold the devices. Unfortunately, I could only fit parts for 3 boxes in the order, as more than half of the coupon's value went into shipping costs to Europe. I guess I will make the remaining boxes of whatever I have here, or laser-cut more parts locally.

I also ordered more buttons, so that I will have 4 devices with proper colors, and one spare.

I decided to use a Pro Mini, and to not store the counts in the EEPROM, but instead to display them on a 7-segment display. Switching the device off and on again will reset it. That's a much more robust and easier to use solution, I think.