IMP card and ATSHA

I’d like to understand more fully how the ATSHA chip works. If I take a connected and programmed Imp card from an April and connect it to a circuit without an ATSHA chip, do I need to clear it and reconnect it? Will it show up as a new device?

Also, are there any recommended SD card sockets that are carried by Digikey, or is the 4UCON socket the best bet?

Also, is this the correct part? I can’t find 19646 on the 4ucon site… at least on the site where you can order parts.

It won’t show up at all. The imp card needs the atsha to identify what it’s plugged into.

Suggested sockets and digikey PNs are here:

Digikey also sell the ATSHA. You need this chip and a 100k pull up resistor.

So how does the imp002 operate? Does it have an internal atsha device?

Because the imp002 isn’t moveable device to device, it has a fixed internal ID. The ATSHA is needed as a small inexpensive way to uniquely identify a device using only one wire.

Ahhh. Now it all makes sense. Thanks!