CR2032 and no motor driver? about magspoof

[samyk]

1. It's true, just like bypass caps aren't always needed. It might work in some cases, and in others, it won't work. Drive it properly and you will increase the readers it will work on (it's worked on all readers that I've tested). Additionally, you'll be limited by the source current of the pins, drastically limiting your output and reducing your range significantly. Thus, use a driver if you want some real current output.

2. Sure, CR2032 should be fine. The cap is necessary to charge up to provide sufficient power when activating (and it may not recharge as quickly with a CR2032, but shouldn't be a big deal). Don't forget the power used by the electromagnet in your calculations. Same size should be fine, let us know how it goes!