In my last post, I had built a reflow oven which will allow me to assemble several sensors at one time. Unfortunately, after populating 100 boards I had an 80% failure rate on all of my assembled sensors! AAARRRGGG!!! After all of that time - after all of that effort - after all of that money spent - an 80% failure rate on everything was a really tough blow to this project. I spent more time testing everything, but I couldn't figure out what went wrong. I had to put the project on hold.
Thankfully my pal Brian Farley came to my rescue and examined everything and came to the conclusion that the reflow process caused micro traces on the MCU that caused it to fail. So he came up with a solution that involved a lot of soldering and re-working each PCB board. It finally took me a month of work, but I was able to get 24 Zombie Sensors to work reliably for the City of Walnut Zombie Tag event. And after two evenings of heavy use, the sensors performed great! I had no failures and they functioned as intended.
So where do I go from here? I know a lot of people would like to purchase these sensors. I have parts to assemble several more. Unfortunately they will take a lot of time to get functioning properly and even more time to test to make sure all of the micro-traces are gone. If/when I sell them. I want to make sure they operate as intended. So until then, stay tuned!