Glen Akins converted a WW2-era engine cowl flaps indicator into a USB peripheral using a microcontroller and four digital potentiometers:

“This project is reminiscent of my USB analog panel meters project but the drive circuitry is significantly less complex. This post starts with a look at the engine cowl indicator, it’s theory of operation, and some ideas to control it using modern electronics. The post then covers the design of the board, the software for the microcontroller, and a Visual Studio C# .NET Windows Forms app for controlling the indicators from a PC.”

“The completed and assembled board. The board features a USB 2.0 Type C connector, a PIC16F1459, four MCP41HV31 digital potentiometers, and a screw terminal strip to connect to power and the indicator.”

“The video above is a quick demonstration of the indicator in use. The indicator is connected to the USB controller board and the USB controller board is connected to my Surface. The .NET Forms app is running and superimposed over the video. As I slide the sliders in the app, the corresponding dial moves on the indicator.”