External RC Displays

Some pilots run a separate cockpit display (KairuhsHQ Cockpit Pro, custom OSD rigs) alongside the model. These displays read regular RC channels off your receiver and decide which screen / role to show. Magic Box doesn’t talk to them directly — it just feeds the receiver, same as any other channel. This page is about how to plan your channels so the display behaves the way you want.

What the display reads

Most cockpit displays expose two control inputs:

Input	What it does	Channel type
Screen Select	Picks the active screen (e.g. 1 of 4)	Multi-position switch on the Tx
Role Cycle	Cycles through enabled roles on the active screen (PFD → MFD → HUD → …)	Momentary button or 3-pos switch

Both are optional. A display configured with a “Default Screen” and a fixed role list will work with 0 channels assigned — you just lose in-flight switching.

Channel budget

Setup	Channels	What you get
Full	2	Pick screen (1 of 4) and cycle roles on the active screen
Minimal	1	Cycle roles on the Default Screen only
Static	0	Everything fixed in the display’s GUI

Pick the lowest one that fits how you fly. Two channels is the cap — you don’t need more.

Magic Box configuration

External displays are just RC channels. There’s no special “external display” mode in Magic Box — you bind a Tx switch (or HOTAS button) to a free channel, exactly like binding ailerons or flaps.

1. Open the Web UI and go to your active Profile.
2. Pick two free channels — for example CH7 for Screen Select and CH8 for Role Cycle.
3. Bind Screen Select — pick a multi-position switch (3-pos or 4-pos) on your Tx. Map it to CH7 with a stepped output (e.g. 1000 / 1500 / 2000 µs for a 3-pos, or 1000 / 1333 / 1666 / 2000 µs for a 4-pos).
4. Bind Role Cycle — pick a momentary button (preferred) or a 3-pos switch. Map it to CH8. The display reacts to changes in value, not the absolute value, so a momentary press is enough.
5. Save the profile. The channels go out on whatever output protocol you’ve picked (PPM, SBUS, IBUS, CRSF).
6. On the display side, set its Screen Select Channel and Role Cycle Channel to CH7 and CH8 respectively. Match the PWM thresholds the display expects (check your display’s manual — values are not standardized across vendors).

Practical layout

A typical 2-channel layout for a 4-screen cockpit:

• CH7 — 4-position switch on the Tx (e.g. SD on RadioMaster TX16S) → screen 1/2/3/4
• CH8 — momentary button (e.g. SH on TX16S) → tap to cycle roles on the current screen

If the display only has one channel slot or you want to save a channel, drop Screen Select and rely on Default Screen — you lose the ability to switch between cockpit layouts mid-flight, but role cycling still works.

Verify before you fly

The Web UI’s live channel view shows what’s going out on every channel. Toggle the Tx switch, watch CH7 step through positions, hit the momentary, watch CH8 jump. If channels move on the screen, they’re going out on the wire — the display will see them.

Vendor notes

KairuhsHQ — manual at kairuhshq.com/manual. Section 6 lists 13 assignable display roles (PFD, MFD, HUD, Air Radar, Track Dash, Ground Radar, etc.). Channel-side configuration lives under Advanced → TX Screen / Role Switching. The manual doesn’t pin down exact PWM thresholds — calibrate against the live channel view in the Magic Box Web UI and the display’s own input monitor.

Have a different display you’d like documented here? Drop a note in the community group.