The Arduino Yun runs OpenWRT linux. If OpenWRT supports a USB device, you are in luck. I was able to use a webcam and a usb-audio device to play mp3 files.
What kind of USB device is the relay module ? Do you have a link to that USB relay module ?
The Arduino Yun runs OpenWRT linux. If OpenWRT supports a USB device, you are in luck. I was able to use a webcam and a usb-audio device to play mp3 files.
What kind of USB device is the relay module ? Do you have a link to that USB relay module ?