Dimming Garmin components

I am posting to see how others addressed dimming Garmin components such as the GTN6XX, GMA245, and the GTR200. The rest of my avionics are from Dynon.

The Garmin components all have reference voltage inputs to externally control the brightness of the screen, button text, etc. They also have an internal photocell if the external source is not utilized.

To further complicate things, Dynon has a "Dim OUT" pin on the HDXs. This is a variable voltage output reference that can control the brightness of other components that have a "light in" such as the Garmin products. Dynon did state that there is a possibility of noise on the audio panel if the grounds are not referenced correctly.

How have others addressed this, and how are your results?

I wired up all my garmin bits to the GAD27 lighting bus circuit and put them on a rheostat. Then I promptly forgot to configure all the units to use the lighting input instead of the built-in light sensors.

Turns out the light sensors work pretty well and I'm just gonna let them stay that way

Same here, except the G5 and GDU-460's aren't well balanced when using the photosensors. I'm sure I just need to tinker with it more.

Thanks, I will let Garmin do it?s own dimming

rdrcrmatt said:

Same here, except the G5 and GDU-460's aren't well balanced when using the photosensors. I'm sure I just need to tinker with it more.

Click to expand...

Yes.. tinker on. It looks like the G5 is fully programmable in Automatic mode.

Minimum Photocell Input
Sets the photocell reading that will result in the minimum display brightness in automatic mode. The default is 10%.
Minimum Display Brightness
Sets the minimum display brightness setting that will occur in automatic mode. The default value is 20%.
Maximum Photocell Input
Sets the photocell reading that will result in the maximum display brightness in automatic mode. The default is 70%.
Maximum Display Brightness
Sets the maximum display brightness setting that will occur in automatic mode. The default value is 100%.

I think it's got to the point of "why bother with a dimming knob" when the auto mode can be set to your liking.