Telegraph

Arduino library for automatically sending Morse code signals. Manual control, speed adjustments, and use of active-on-low relays are supported.

Usage

Check the example sketches, especially Telegraph_Demo, for more information.

Setup

To create a Telegraph object, use the code:

Telegraph telegraphName(pinNumber, speedInWordsPerMinute, HIGH);

(Use LOW instead of HIGH for an active-on-low relay. If you're using a relay and aren't sure whether it's active-on-low or not, just try it with HIGH; if your relay is active-on-low, keying will be opposite of what is expected.)

Sending messages

To send a message in Morse code, run this:

telegraphName.send("MESSAGE");

The following characters can be used in messages:

ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890.,?'!/()&:;=+-_"$@

Lowercase letters are supported. Unsupported characters will not be transmitted, but may cause gaps in timing.

Adjusting speed

To change the transmission speed after creating the Telegraph, run:

telegraphName.wpm = 25;

Manual control

To manually turn the pin on and off, just use these commands:

telegraphName.on();
telegraphName.off();