We were stress-testing the prototypes today and found problems with reliability. We can control the device by phone very nicely since we have most of the device state stored in non-volatile memory. But for testing we just set some volatile variables to run the test and found that when left overnight something would reset the SOC. At first we thought it was the relatively violent action of stopping the loaded motor with a strong current in reverse. But removing that didn't fix the problem. We may have some errors in the logic of our device and such things are a pain to debug as they only repeat very rarely. We have debugging functionality built into the firmware and we will have to monitor the logs to see what happens just before the device resets. This isn't a showstopper for us but still another little annoying thing to deal with.

I was assembling two more prototypes today. It takes so long to actually build these boards by hand. Sure I did other stuff too but basically I dealt with this for most of the day. Soldering 0.5 mm pitch QFN and 0402 passives by hand is bad enough without having to run to a meeting every 15 minutes. But at least we'll have two more devices for our programmers and testers now. We have been dealing with this project for so long that we had accumulated a heap of devices of various vintage and most are not board level code compatible. So we had to build a custom firmware for almost every device until now. Now we'll have all pretty much the same hardware so at least we can't blame bugs on old pcbs and wiring any more.

We also received some new TI current sensors today to test. The weird Microchip things we were using are still duds. I did hear back from Microchip support and they requested more information but I will try the TI ones first since all this drama has left me hating Microchip and if possible I'll go with TI. Since we are using a motor driver from TI anyway it will be easier to source components later too so it's not just my being angry.