USB 2.0 switch with switches

I was using multiple audio devices that were connected via USB. Selecting the device was a struggle, as I had to be configuring the OS or pulling the cables whenever I needed to switch the audio output.

There were a fair selection of USB hubs with switches commercially available, but their build quality was quite shoddy. No mounting flanges and the connectors were easily damaged. In the long run there were also reliability issues even when using an external power supply, which rarely shipped with the commercial hubs.

Specification

• Mounting flanges on the enclosure
• Easy to use switches
• Clear indicators that reveal the state of the machine at a glance even in dark environment
• Reliable operation
• At least USB 2.0

Design

Schematics

I decided to go with USB 2.0 rather than newer specifications for multiple reasons. Power budget was simple, quality control for bare PCB was less critical, ICs were less expensive and well tested.

Switches

Indicator lights are integrated in the switches so the user can be certain if the switch is open or closed. The indicator will only be lit if the port is available. If the upstream USB is unconnected the indicators won't light. They will also turn off in case of over current is drawn by the peripheral.

Connectors

DC input is required for reliable operation and compatibility. USB connectors can be selected to be high retention force models, so they don't fall off no matter which orientation the device is installed. The screw connector for power supply will also hold reliably.

Housing

The housing and the electronics were designed with Fusion 360. Even the toolpaths were generated with Fusion 360. Machining was done with a custom CNC mill and Linux CNC -based controller.