In a few words – we had to redo everything, switching from analog to digital.
0) Samples from China were WRONG with some of the components installed backwards(!!!) on the board
1) Everything is VERY small so we had to find engineers with good eyes and a lot of patience (changed 3 different engineers, who couldn’t accomplish the job)
2) We assembled a sample with large atmega microcontroller and it didn’t work properly
3) We found mistakes in code and problematic parts on the sample (for example, we used analog trigger with high frequency status reading, which gave us problems with button, so eventually we switched to digital)
4) We recompiled the code for attiny-45
5) Now making another sample from scratch by hand and trying to make gerber file with the least amount of layers possible (to make it easier for factory to make). Will try to manage it from 4 to 2 layers.
6) Crossing fingers to have everything ready asap to order 5 – 10 samples made in Moscow
7) If samples perform well we will hop on the plane to China immediately.