Almost Irresistible

I saw this on Ebay:

Source: https://www.ebay.com/itm/287339757881

It's a small, notecard sized display - E-paper like the various E-book readers.  The virtue of E-paper is that it requires no power to keep alive.  Indeed these Ebay displays are powered by NFC (near field communication) like the smart credit cards.  So it doesn't need a power supply, just an NFC signal to upload the image you want to display.  Then the image persists even if there is no signal present.  This NFC signal probably comes from an app for an NFC enabled phone, which I now have !  But it could come from something like an Arduino with an NFC shield.

But you are probably thinking: can't you just write (or use a computer printer) a message or image on regular paper or card stock - that doesn't require any keep-alive power, right ?  That's certainly true, as I said, it's almost irresistible :(

I was thinking of E-paper for a clock display but there are two problems, this NFC E-paper display is kinda slow so the time might be off by a couple seconds by the time the display updates.  Second, 4.2 inches (diagonal ?) is kinda small - I'd like something I could see from farther away.  Bigger E-paper means a bigger price.

I'll keep thinking about it, maybe there is an application that might justify buying one - after all an E-paper ham radio callsign badge really can't really be justified :)

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm