HDX level soft key

[RVDan]

I just upgraded to HDX from Classic. I was familiarizing myself and came up with a question. With the autopilot set up with expert controls, I can’t find a ”level” soft key. There is one in simplified controls but I can’t find it when in expert controls. Anyone know where it went?

 

[Rhino]

The soft key isn't available in Expert Mode. It assumes you're using an SV-AP-PANEL. And the SV-AP-PANEL is disabled if you switch the AP to Simplified Mode. It's sort of an either-or proposition. If you don't have an SV-AP-PANEL, you can install a simple momentary external LEVEL button on your panel that sends ground to the correct pin on the Skyview. You can buy the button from Dynon, or simply make your own, which is a lot cheaper. The button from Dynon has two wires, one for the ground and one for the backlight. If you build your own switch, you only really need the wire for the ground. For multiple displays, the button should be connected in parallel.

 

[maartenversteeg]

I think there is a note regarding using a single button for multiple displays, that states that there should be diodes in line for each of the displays so that if one display is powered off that the level button still works on the other display.

 

[Rhino]

Good point. That's noted in the section on the SV-BUTTON-LEVEL from Dynon when connecting to both displays (page 10-15 in revision AN). That's because the pins on the displays have a constant bias voltage applied, and the failure of one display could potentially prevent a button from triggering the other, or trigger it constantly. A diode isn't necessary if you only connect the button to one display. It also only functions as a failover if connected to both displays, so it isn't really necessary if you don't need that kind of redundancy. The external button is just a convenience item otherwise. But, if you do connect to both displays in parallel, it certainly wouldn't hurt to have the diodes, whether you're using the SV-LEVEL-BUTTON, or your own button, even if you don't need the redundancy.

By the way, the manual mentions the 1N914 diode from Radio Shack. Radio Shack doesn't really exist anymore, but 1N914 diodes are widely available elsewhere.

 

[RVDan]

I suspected that might be the case. I do have the AP control panel, but my right seater wanted a button on his side so he didn’t have to reach across.

 

[Rhino]

Then definitely use diodes if you install a switch, because the AP Panel introduces another voltage path.

CORRECTION: The AP-PANEL communicates over the serial port, so a diode is not needed simply by virtue of having the AP-PANEL installed.

 

[Rhino]

Not sure if anyone will find this helpful, but I'm soliciting feedback.