24 March 2019
I am still not sure exactly why, but the People Counter just doesn't like the smaller Hammond box. Maybe it's because the sensors are so close to the sides of the box that prevent them from working well.
In any case, I put the new board into the old Bud box and repeated the testing from yesterday and I was very happy to find that the new People Counter pcb with the same old program and Bud box worked at 100% accuracy. I tried five passes (ingress + egress) myself (5' 11") and captured all 10 events. Then I asked my wife (5' 6") to try a couple of times and was able to see her two ingresses and two egresses. Then one more time with me following close behind her on the way in and on the way out. The People Counter captured all events in the proper order. It's like magic!
The Bud box is not a bad option (well, it's the only one that works so far!). It's a bit bigger than I was hoping to get away with, but the advantage of the larger size is I can use two AAA or AA batteries instead of a coin cell to extend the time between battery changes. At the measured < 50 uA average current usage, two AA batteries provide (2400 mAH/0.05 mA) about 5 years of service. Lighter AAA batteries about half that. Pretty close to set and forget.
I am gratified that the pcb design and firmware I developed seem capable of repeatable 100% accuracy. I was afraid I had a one-off on my hands.
I need to make a few sets of these People Counters using the Bud box and deploy them in a test friendly environment to get some real-world test data. I will likely ask my machinist friend to drill the holes for me to make sure these are all the same. I have some likely venues for this next stage in testing. More to come....