Modules driving 4 relays with DTMF

Here is a small overview of the Remote Relay Module writes to drive the 4 relays available on the SvxLink Card (available soon).

It's possible to modify the used codes (For example, sysop code which is before the command)

Here are the default parameters:

  • 9# Enable the RemoteRelay
  • # to disable

Relays are on GPIO port 20,21,22,23

3 codes available per relay:

  • OFF = 0
  • ON = 1
  • PULSE = 2 (Pulse of square wave of 100ms)

The codes for the relay K1 (gpio 20) will be:

  • 200# = OFF
  • 201# = ON
  • 202# = Impulsion of 100ms

Syntaxe: <numéro gpio> <etat> # (for validation).

It will be possible to integrate this module on your relay even if you do not use the SvxLink Card by adding relay cards that are easily found on the net. NOTE: This is an illustration picture, it means that the wiring does not match my setup.

Diagram of the relay control of the Svxlink Card:

Files are on this link:

Below is a short video demonstration, showing the full operating cycle (activation, control relay ON, OFF, pulse “Pulse” and disabling with vocal synthesis confirmation).