Ethernet Relay Board

It’s not a project in itself; nonetheless, the Ethernet relay board I purchased in 2012 has proven to be a versatile part in my inventory. In particular, the board is a relatively easy way to switch USB flash drives. Here is an example.

Wiring the VCC and ground lines from destination USB devices through the relay board to a source USB connector and connecting the D+ and D- lines together gives you the ability to “insert” and “remove” a USB flash drive from a computer by switching selected relays on the Ethernet board.

At the factory, we personalize products by installing a specific software package on our HSM appliances. We need to start from a manufacturing golden image. I used USB drives and the relay board to automate a step of testing the personalization process. When personalization finishes, a Windows command script:

• turns off the appliances

• enables the USB flash devices via the Ethernet relay board

• turns the appliances back on

• allows a Clonezilla imaging program on the USB flash drives to run to completion

• turns the appliances off

• disables the USB flash devices

• turns the appliances back on to boot to the hard drive that now has installed the manufacturing golden image.
  

The setup saved engineering effort as we could run unattended tests throughout the day and evening.