WiFi thermometers: save different location string as const across many devices

Question

I've built a very simple WiFi thermometer out of an Adafruit ESP8266 HUZZAH breakout board and a TMP36 temperature sensor. I have it reporting the temperature over wifi to my computer which will be storing the data in a database for monitoring purposes. I'd like to make multiple of these devices and place them around the house. My question: I currently have the location of the board as a const char* on the board itself. Doing this for multiple devices is just a bad idea and a nightmare to manage. Is there some way of setting a location variable on the board that will persist across shutdowns? Or am I coming at the problem from completely the wrong direction?

• Majenko: Why not just use the (unique) IP address of each module to identify it and map that to a name on the PC?
• Taelsin: I was thinking that would solve the issue, but I'd rather have the resolution contained within this system rather than relying on configuring my router as well.

Answer 1

With a set of DIP switches or jumpers on some of the GPIO, you could encode a unique number for each one - 16 of them with 4 I/Os f/ex. The same code could run on all of them, sample the unique ID report it along with the temperature. Let the PC-side map IDs to locations.

• Taelsin: I like this. Your answer gave me an idea though. I can get a MAC address from the breakout board. Would the MAC ever change? If not, I could send the MAC of the board along with the other data and do some server side mapping with the MAC.
• JRobert: I don't know how the Lua firmware works, but the AT+ interpreter firmware includes commands to set the chip's MAC address, so, yes, it can be changed, but that's a change you would have to make, not one that I could ever imagine would be programmed to happen without you taking explicit action.
• Jaromanda X: The MAC address comes from the ESP8266 chip, not from the breakout board
• JRobert: @JaromandaX: Yes, that's correct. And ?
• Jaromanda X: Just clearing up @Taelsin's misconception that the breakout board has something to do with the MAC address, if that's OK with you