Robot Beeps

Pioneer, Peoplebot, Powerbot and Amigobot robots use the small piezo speaker (buzzer) on the side or top control panel to indicate certain states:

When the robot is first turned on and the firmware successfully starts up, it plays a quick ascending scale of tones.

When a program first connects to the robot successfully, it plays two ascending tones.

If the battery voltage is below the warning limit set in the firmware configuration, the robot will emit a constant series of long beeps, each beep lasting for about a second followed by about a second of silence. The battery voltage is displayed by the ARIA 'demo' example program, in its "teleop" and "position" modes, and by some other example programs including MobileEyes when connected to most server examples. You may also hear a single battery warning beep or two if a heavy load is suddenly placed on the batteries which lowers their voltage briefly (e.g. trying to turn a Pioneer AT on a high-friction surface).

If a program connects to the robot, but does not send any command for a period of time (configurable), then the firmware's "Watchdog" mode is triggered, which stops the robot from moving, and emits a constant series of short beeps, each beep lasting about half a second followed by about a second of silence. This can also happen when a program exits but the serial port remains open. (Note, older firmware revisions did not do this.)

If a robot has an emergency stop (E-Stop) button and E-Stop is engaged, it will emit a short high and short low note, a pause, and repeat.

A client program may also use the SAY command (#15) to play tunes. See Robot beep (SAY) example code for an example of using the SAY command in ARIA. (None of the ARIA or ARNL example programs do this.)

Sounds may be disabled in the firmware configuration or by a client using the SOUNDTOG command (#92), in which case no sounds will be played at all.