DPMS emulation via switching the monitor off & on with gpio. Disclaimer: Your monitor wiring can be different, be extremely careful not to damage your wiring. You might need to make your own schematics, suitable for your hardware.

This addon is motivated by use of Raspberry PI 3 + LibreElec (Kodi JeOS). The issue of such solution is, that Raspberry PI essentially cannot utilize the CEC/DPMS features over HDMI-to-DVI connected monitors, such as mine Lenovo L2440p. However, it's okay with monitor turning off and on again.

Therefore, I decided to use RPI's GPIO to switch the monitor off and on again.

First of all, the monitor controls consists of single PCB with orange/green LED and 5 control buttons. The PCB is connected to monitor with 6-pin 2mm connector. However, only 5 lines of the connector are used - the 6th line is not handled.

In order to switch the buttons via GPIO, I've created a small parasite, which I attached in between the controller PCB and monitor cable. One GPIO pin is used to toggle the monitor ON/OFF state, the other is used to read the current ON/OFF state.

Finally, if you use Raspberry PI 3 (as I do), you need to pick unoccupied GPIO pins. In my setup, the toggle pin is logical 17 (physical 11) and sense pin on logical 27 (physical 13).

As the Raspberry PI is not the only SBC running LibreELEC, I decided not to use the PI-specific libraries. Thus, this addon uses GPIO subsystem accessed via /sys/class/gpio with individual exported GPIO pins.

First, create corresponding addon zip file

 git clone https://github.com/xrucka/kodi-gpio-pseudodpms.git ./script.service.gpio-pseudo-dpms
 zip -r script.service.gpio-pseudo-dpms.zip script.service.gpio-pseudo-dpms

Then install through kodi addon management (install from zip file).

For most users, the default values of everything should be ok. You'll need to set up pin bindings (sense + toggle).

The addon offers following configuration options:

• Use sense for toggle control - whether to read current monitor state and toggle only if needed.
• Export logical pins (if your kodi does not have permission to write to gpio sysfs subsystem, you'll need to export the pins manually).
• Sense pin logical ID.
• Toggle pin logical ID.

Furthermore, the addon offers 2 modes of operation - simulating either button, or switch. For button mode operation (default, should cover usual usage), set:

• Toggle duration - how long to keep logical 1 on the switch pin.
• Toggle operation - Pulse (button)

If your display requires holding logical 1 to keep it open (and possibly does not provide sense signal), you can use the Hold mode:

• Toggle operation - Hold (switch) ; which will keep logical 1 on the control signal as long as the display should be kept on and sets the line to 0 for shutdown.
• You might further want to piggyback the sense signal to the control one. You can achieve that when both pin logical ID's match.