> For the complete documentation index, see [llms.txt](https://docs.auterion.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.auterion.com/app-development/simulation/auterion-simulator/hardware-in-the-loop.md).
# Hardware in the Loop
Run Auterion Simulator with a physical Skynode.
Hardware in the Loop (HITL) runs Auterion Simulator with a physical Skynode.
### Run a HITL simulation
1. Go to the filter menu, and select Hardware as execution target.
2. Connect the physical devices. Wait for automatic discovery to find them.
3. Set the required device count for each supported device type.
The launcher shows the available devices and execution plan. Increasing a count reduces the available count for that device type.
4. Confirm each device has the required AuterionOS version. Select **Set up devices** to prepare it for HITL.
This step does not install AuterionOS.
5. Select devices in the **Vehicles** tab. Select **Approve all** or **Flash** to install a required image. (For this demonstration we purposefully chose a skynode-n image on skynode-s device)
