Arduino Bluetooth + HP41c

[murphy9]

I'm readying for IoT word in SFO this month and I started to explore a number of bluetooth options - as small as possible. I came across something called RFDuino, which looked like it could be the answer to the connection dreams for the HP41c. It fits in a pac module and has enough IO, as well as low power BTLE and a simpler programming support. If this had the ability to emulate a ROM Pac and connect via Bluetooth, then then the opportunities are endless?

The best thing is that the device is only around $15 per unit.

[Monte Dalrymple]

The space inside a module housing is only about 13mm x 23mm, so the 15mm^2 RFDuino probably wouldn't fit. Especially considering that you would also need a voltage regulator and at least a couple of level shifters. Close, though.