LED Annunciator

A quick and dirty little device to inform people you are on the phone or in an appointment with a traffic light. The state information are generated by a groupware or messaging application that writes a single letter code into a file.

Command	Meaning
a	Turn on all leds
0	Turn off all leds
r	Switch to the red line
g	Switch to the green line
y	Switch to the yellow line

AnnunciatorServer takes the code and sends it via serial port to the device. Alternatively, similar commands can be send by an infrared remote control.

Hardware

An Arduino Nano with nine leds on pins D02 - D10. The leds are arranged in three rows (red, yellow, green) of three leds each. A YS1838B infrared receiver is connected to D11 and sits on top facing backwards.

Software

led-annunciator

The Arduino code.

checkLedPins

A program to check the led/pin mapping by turning them on one by one.

annunciatorServer

The shell script that checks a commandfile and sends single-character commands to the serial port. This is useful when the commandfile needs to sit on a network share.

Room for improvements

• Sometimes the ir receiver starts to send random codes
• As all leds are connected individually, many more commands can be defined.