Sim Racing Gear Indicator Ganganzeige Flag DIY

DIY Sim Racing Gear Indicator

This DIY gear indicator was specially developed for sim racing simulators and displays the currently selected gear via an LED matrix. The compact housing can be easily integrated into almost any sim rig or dashboard

The display is operated via SimHub. SimHub reads telemetry data from supported racing simulations and transmits the currently selected gear to the Arduino, which then displays it on the LED matrix

Dimensions

• Width: 45 mm
• Height: 45 mm
• Depth: 34 mm

Required Components

• LED Matrix MAX7219 (8×8)

  - https://de.aliexpress.com/item/1005006222492232.html?spm=a2g0o.order_list.order_list_main.95.4f085c5fFoNz1z&gatewayAdapt=glo2deu

• Arduino Pro Micro Type-C

  - https://de.aliexpress.com/item/1005008804370504.html?spm=a2g0o.productlist.main.8.53964b8epWhuDa&aem_p4p_detail=20260313085546727415102240160000695738&algo_pvid=7c4c5f12-d960-4d01-8cc4-de7e3c1a5fa9&algo_exp_id=7c4c5f12-d960-4d01-8cc4-de7e3c1a5fa9-7&pdp_ext_f=%7B%22order%22%3A%2281%22%2C%22eval%22%3A%221%22%2C%22fromPage%22%3A%22search%22%7D&pdp_npi=6%40dis%21EUR%214.89%214.89%21%21%2137.85%2137.85%21%402103856417734173463182816e41e4%2112000046732279359%21sea%21DE%21888527740%21X%211%210%21n_tag%3A-29919%3Bd%3Aec44f1e7%3Bm03_new_user%3A-29895&curPageLogUid=lJitYwtYXUWB&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005008804370504%7C_p_origin_prod%3A&search_p4p_id=20260313085546727415102240160000695738_3

• 2 mm acrylic sheet (black / grey transparent) for the front window

  - https://de.aliexpress.com/item/32857098929.html?spm=a2g0o.order_list.order_list_main.10.4f085c5fFoNz1z&gatewayAdapt=glo2deu

• 4× M3 screws (20 mm)
  - https://de.aliexpress.com/item/1005006037706986.html?spm=a2g0o.cart.0.0.362f4ae4IpuDUD&mp=1&pdp_npi=6%40dis%21EUR%21EUR%204.49%21EUR%204.49%21%21EUR%204.49%21%21%21%402103956a17734174872573963e908b%2112000042728519164%21ct%21DE%21888527740%21%211%210%21&gatewayAdapt=glo2deu
• 4× M3 heat-set inserts

• 2× M5 heat-set inserts

  - https://de.aliexpress.com/item/1005003582355741.html?spm=a2g0o.order_list.order_list_main.65.4f085c5fFoNz1z&gatewayAdapt=glo2deu

• 5× wires 22 AWG / 0.34 mm²
  Length per wire: 30–40 mm

  - https://de.aliexpress.com/item/1005010662031332.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.2.1151Q4uwQ4uwRd&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.354490.0&scm_id=1007.40050.354490.0&scm-url=1007.40050.354490.0&pvid=3cc0c83e-46c1-4ded-b911-ee918cacd37c&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40050.354490.0,pvid:3cc0c83e-46c1-4ded-b911-ee918cacd37c,tpp_buckets:668%232846%238107%231934&pdp_ext_f=%7B%22order%22%3A%2228%22%2C%22eval%22%3A%221%22%2C%22sceneId%22%3A%2230050%22%2C%22fromPage%22%3A%22recommend%22%7D&pdp_npi=6%40dis%21EUR%212.05%212.05%21%21%2115.87%2115.87%21%40211b80d117734172269953543e285f%2112000053110664188%21rec%21DE%21888527740%21X%211%210%21n_tag%3A-29919%3Bd%3Aec44f1e7%3Bm03_new_user%3A-29895&utparam-url=scene%3ApcDetailTopMoreOtherSeller%7Cquery_from%3A%7Cx_object_id%3A1005010662031332%7C_p_origin_prod%3A

Wiring

The wires must be soldered accordingly:

• VCC → VCC
• GND → GND
• DIN → 3
• CS → 4
• CLK → 5

All connections should be cleanly soldered to ensure stable and reliable signal transmission

Installing the LED Matrix

The LED matrix is inserted into the front from the back.
Thanks to the precise design, it can simply be pressed into the opening and will then hold itself in place. Additional fastening is usually not necessary

Front Window (Acrylic)

The front window is laser cut from a 2 mm acrylic sheet

• The required DXF file is included
• Material: black / grey transparent

After laser cutting, the sheet is pressed into the housing from the front and usually holds due to the fit

If desired, 1–2 small drops of superglue can be used for securing it

Mounting to the Sim Rig

On the back of the housing are two M5 heat-set inserts.
These allow the gear indicator to be later attached to a sim rig, dashboard, or bracket

Assembly

1. Insert heat-set inserts (M3 and M5) into the housing
2. Press the LED matrix into the front from the back
3. Solder the wires according to the pinout
4. Insert the Arduino and place the board onto the matrix
5. Connect the housing parts with the M3 screws (20 mm)
6. Insert the front window from the front and lightly glue if necessary

Setup in SimHub

The display is controlled via SimHub

Add Arduino to SimHub

1. Start SimHub
2. Select "Arduino" in the left menu bar
3. Connect the Arduino to the PC via USB
4. Go to "My Hardware" in SimHub
5. Click on "Add Arduino"
6. Select the appropriate COM port device (Arduino Pro Micro)

⚠️ Important:
Before uploading the firmware, the MAX7219 LED Matrix must be selected as the hardware used in the device selection. This will automatically create the appropriate sketch with matrix support in SimHub

Configure LED Matrix

1. In SimHub, select the added Arduino
2. Under "Matrix / LED Displays", add a MAX7219 LED Matrix
3. Set the pinout according to the wiring:

• DIN → D3
• CS → D4
• CLK → D5

1. Number of modules: 1

    

   Then click on "Upload Sketch"
   SimHub will now automatically upload the appropriate firmware to the Arduino

    

   After a successful upload, the Arduino will appear in the hardware list

Result

In the end, you will have a compact, stable gear indicator for your sim racing setup that is easy to mount and clearly displays the currently selected gear