The modes are activated by using the left/right buttons on the dpad.
The tv-b-gone mode cycles through approx the top 135 most common TV's 'off' codes, one at a time.
The MQ303 mode is the breathalyzer function. First, the circuit needs to heat the sensor for approx. 5 seconds. Afterwards, a reading can be obtained. The value is a representation of the resistance across the sensor, not a specific BAC (we didn't want to be sued by someone claiming our badge said they weren't drunk).