What’s involved in connecting multiple PiGlows to the Raspberry Pi, e.g., can the device’s I2C address be modified ? (sorry, I’m a Newb)
Unfortunatly the address is fixed on the PiGlow itself, you’ll have to use something like a multiplexer to switch between each PiGlow before writing your data
While it can’t be directly modified, there are ways around that.
For more than two, what you effectively need, as Boeeerb suggests, are ways to Multiplex the two I2C lines. Search for Digital/Analog multiplexers.
For two, and using things you may already have handy, you could use an Arduino to drive the second one. I’ve written a library for this, which you can find here: https://github.com/Gadgetoid/PiGlow-Arduino
I’d suggest talking to the Arduino over serial, and setting up some simple commands for controlling the PiGlow.
The latter solution is a little on the complex side, though!