The Twiddler 4 outputs its current status in text format.
A typical string looks like this:
cfg=0 fw=3.0 batt=4218 addr=D4:ED:8A:28:CF:03
cfg=0 - the Default Factory config is being use.
fw=3.0 - the Twiddler 4 is running firmware version 3.0
batt=4218 - the battery is currently outputting 4218mV.
addr=D4:ED:8A:28:CF:03 - the Bluetooth address of your device is:D4:ED:8A:28:CF:03