The round one

As previously blogged, I created an NFC RFID reader based on the PN532 NFC chip.

It works well, and includes red/amber/green LEDs and tamper switch and even contacts for a "door bell". This makes it ideal for access control.

But I decided some cases may look better with a round modules. So I wrote code to measure track lengths in KiCad PCB files, and then code to make a spiral track, which I made the same length, and then made a round version of the same thing.

It works. It worked first time. Indeed, the solder paste and cook worked first time - no re-work - no glitches - just worked. I am really pleased.

One of the small tweaks was around the reverse mount LEDs which used to tombstone in the oven - that is all fixed nicely now.

Other changes are that the connectors are all SMD now to make the other side "clean".

Which leaves me wondering if I should add a logo or something on that side. I am really not sure. I also think purple solder resist may be nicer. The main thing is I want a distinctive appearance / brand that can compete with elechouse on Amazon. Suggestions welcome.

Of course, what is super frustrating is that these are all prototypes - I cannot really make commercially until the global component shortages are sorted and I can actually order 100 of the PN532 or indeed anything else! Once sorted, I plan to put these on Amazon.