Troubleshooting

We had some problems with poor contact on the PCB. The board was fully tested again and some soldering was re-done with extra care and more tools, such as flux. Now it’s working a lot better.
The spring we’d bought first was too unnecessarily strong, so the servo was not performing that well. We bought a new spring which is more appropriate - it’s still stronger than what we need, but it’s not as problematic as the other one.
We frequently had poor contact issues when using the fingerprint scanner. This is because the fingerprint scanner connector is considerably more compact (1.27mm step) and thus we tried and adapted it for 2.54mm connections wire-by-wire. In order to solve this, we made a KK connector for it - it now feels way more secure.
The webcam QR code recognition was working (as could be seen from other videos), but as we started doing more extensive testing we realized some specific conditions (mostly lighting-related) made it perform poorly. This was foreseen as a risk. We tried adjusting some internal parameters and were about to open the camera for fine-tuning the focus for this application - but then a really nice guy from other team casually said he had an actual QR code scanner, which we’re now using! The integration was similar to the numeric keyboard - not hard, but not trivial either.
- It works great!

Demonstrations