I'm not too worried about Patents. Most of them were 17 year duration and are expired. The secret is in the materials, most of which are no longer made.
I went optical instead of Hall because PLers understand optical and can get the parts easily enough. There is a wide variety of photodiodes, but few standardized hall sensors, But I will set up the program to take either.
You can get Hall sensors out of hard drives and brushless motors in CD/DVD players.
Oh well, and I doubt Mr Dryer would object to Lumia making a comeback. He did perfect it!. I've read a story about 1 employee paid to do nothing but go around town looking for lumia materials.
Steve
Qui habet Christos, habet Vitam!
I should have rented the space under my name for advertising.
When I still could have...