The SimHub LED editor
Last updated · SimHub 9.11.22
The LED editor is where an LED strip stops being a rev bar and becomes a configurable instrument. A profile holds an entire LED definition and is remembered per game. Inside it, individual effects define a start position, LED count, mirroring, dimming and colour, while groups bundle effects and apply scroll, blink or conditional transforms to all of them at once — assembled either Layered, where effects stack, or Left to right, where they occupy separate regions. The test data editor lets you simulate RPM, fuel and turbo values without running a game, which turns a fiddly job into a quick one.
This is one of the most capable parts of SimHub and one of the least written about. The test data editor in particular is barely mentioned anywhere, and it is the difference between configuring LEDs in ten minutes and configuring them across three sessions.
Profiles
A profile contains an entire LED definition — every effect, every group, every colour. Profiles are remembered per game, which is more useful than it sounds.
- A rally game and a GT game want different things from the same strip: stage times and pace notes against lap deltas and flags.
- A game with no flag data has no use for a flag effect, and a profile without one is simpler to reason about.
- You can experiment freely by cloning a profile rather than editing the one that works.
Clone before you experiment. The default profile is the thing you fall back to when a session of tinkering goes wrong. Clone it, work on the copy, and keep a known-good original.
Individual effects
An effect is one behaviour applied to a range of LEDs. Its settings:
- Start position
- Which LED it begins at. This is how you put two different effects on one physical strip — one at LED 0, another at LED 8.
- LED count
- How many it occupies from there. Together with start position, this carves the strip into regions.
- Right-to-left mirroring
- Which direction it fills. Per effect, not global — so a symmetrical bar filling outward from the centre is two effects, one mirrored.
- Dimming
- Per-effect brightness. Essential when a bright warning shares a strip with a subtle background.
- Colour
- Fixed, or a gradient across the effect's range.
Because effects are positioned and counted individually, a single 16-LED strip can be a rev bar across all 16, or an 8-LED rev bar with a 4-LED fuel gauge and a 4-LED flag indicator. The strip is a canvas, not a bar.
Groups, and the two assembly modes
A group bundles effects so a transform applies to all of them at once — scrolling, blinking, or appearing only when a condition is met.
Conditional groups are the powerful part: a group that exists only when the pit limiter is on, or only when fuel is low, or only under a yellow flag. That is how one strip carries several meanings without becoming cluttered — the extra meanings are simply absent most of the time.
How a group's children combine is set by its assembly mode:
| Mode | What it does | Use for |
|---|---|---|
| Layered | Effects stack on the same LEDs, later ones drawing over earlier ones | A warning that overrides the bar underneath it |
| Left to right | Effects are placed one after another along the strip | Dividing the strip into regions with different jobs |
Getting this wrong is the usual reason an effect "does not appear": in Layered mode something is drawing over it, and in Left to right mode it has been pushed past the end of the strip by the effects before it.
The test data editor
This is the feature worth knowing about, and almost nobody mentions it.
Configuring LEDs normally means driving, watching the strip, stopping, adjusting, and driving again — while trying to reproduce the exact conditions that trigger the effect you are working on. Low fuel, a yellow flag, and the redline are all things you cannot summon at will.
The test data editor lets you set telemetry values directly — RPM, fuel, turbo and the rest — with no game running. The strip responds immediately.
- Sweep RPM by hand to see exactly where the bar starts filling and where it flashes, instead of inferring it from a fast-moving strip.
- Set fuel to 5% to check the low-fuel warning without draining a tank.
- Trigger a condition that only occurs in specific race circumstances, on demand.
- Work with the rig off. No game loading, no session to join.
This turns a three-session job into a ten-minute one. If you are configuring anything beyond a plain rev bar, open the test data editor first. Everything else about LED configuration is easier from there.
A method that works
Clone a profile
Never edit the one that currently works.
Decide the regions
On a 16-LED strip: what occupies which LEDs, and what is conditional. Sketch it before you build it.
Build the resting state first
Whatever the strip shows when nothing special is happening — usually the rev bar. Get that right on its own.
Open the test data editor and sweep it
Confirm the fill range, the direction and the flash point without driving anything.
Add one conditional group at a time
Test each with the test data editor before adding the next. Two new effects added together are hard to debug.
Check what overrides what
In Layered mode, confirm the important thing draws last. This is where warnings get lost.
Drive it
Only now. The test data editor gets you to a configuration that is nearly right; driving tells you whether it is readable at speed, which is a different question.
Common questions
What is a SimHub LED profile?
A complete LED definition — every effect, group and colour — stored as a unit and remembered per game. That lets a rally game and a GT game use the same strip for different things without reconfiguring anything.
What is the difference between Layered and Left to right assembly?
Layered stacks effects on the same LEDs, with later ones drawing over earlier ones — use it for a warning that must override the bar underneath. Left to right places effects one after another along the strip, dividing it into regions with different jobs.
Why doesn't my LED effect appear?
Usually assembly mode. In Layered mode something later is drawing over it; in Left to right mode the effects before it have pushed it past the end of the strip. Check the group's mode and the start positions before assuming the effect is misconfigured.
What is the SimHub test data editor?
A tool that lets you set telemetry values directly — RPM, fuel, turbo — with no game running, so the LEDs respond immediately. It is how you check a low-fuel warning without draining a tank, and it is the single biggest time-saver in LED configuration.
Can one LED strip show more than the revs?
Yes, and that is the point of the editor. Effects have a start position and an LED count, so a 16-LED strip can be an 8-LED rev bar plus a 4-LED fuel gauge plus a 4-LED flag indicator. Conditional groups let extra meanings appear only when relevant.
How do I make a symmetrical bar that fills outward from the centre?
Two effects: one starting at the centre going right, one starting at the centre with right-to-left mirroring enabled. Mirroring is a per-effect setting rather than a global one, which is exactly what makes this possible.
Sources
Related guides
SimHub is developed independently by Wotever and is not affiliated with oesimracing. This page was checked against SimHub 9.11.22 on 4 August 2026; where the interface has moved on since, the version stamp tells you how far. More on what SimHub is and what it costs.