One of my first Arduino projects was this IRLP Simplex Node Controller. This
controller provides several functions:
- CW ID
- PTT LOCK
- FAN Control
- Courtesy Tone
This controller is for simplex IRLP nodes which which controls ID, fan, courtesy tone and a PTT lock (transmit hang) funciton. The CW ID’er allows the audio to be mixed with the controllers CW ID so that it will only ID when some one is speaking accross the link or when the node is idle. The controller frees up the node for extra process scripts for ID’s, Fan Control, and courtesy tones. With the PTT Lock (Transmit hang) timer, the transmitter will be protected by a “hung” transmitter and will force an unkey of the transmitter when a timeout has occured. This PTT Lock will also send an LOCK tone and UNLOCK tone when the PTT line is unkeyed.
The controller is interfaced to the irlp/transmitter via a “breakout board” which allows the user to customize the radio interface.
I have included a breakout board schematic for a GM300 that I use for both simplex node and repeater control even thought I have only tested the controller in simplex operation.
Construction of the controller was done with a proto-boards from Radio Shack. When building the controller board, keep in mind that you want to have access to the adjustment resistors, which was an oversight when I built my original boards.
Some of the modules can be obtain in kit form from the following online stores:
LCD117 Kit & 16 × 2 Blue LCD Package LCD 117 Kit, see available displays
Two boards will need to be built, one for the IRLP audio breakout board which interfaces the audio, PTT, and COS signals to the IRLP Controller board and another board which contains the interfaces to the Arduino Bare Boards Board.