(Or at least something other than just Line-In). According to other posts, my Roland Digital Piano should be showing up here as a device. Within the Built-in Input tab > Source: the only option from the drop down box is Line In. However, there seems to be an issue within Utilities > Audio Midi Setup > Audio Devices (window). My computer detects it, and the Roland detects the computer (evident when I run the tests and both computer and Roland make the sounds they should). In Utilities > Audio Midi Setup > Midi Studio (window) : The Roland Digital Piano shows up as a device. This was successful and my Mac detects the device. I've installed the driver supplied by Roland, suitable for the piano model and my operating system (Roland Digital Piano Driver Version 1.0.0 for Mac OS X 10.6). I have a Roland FP-4 digital piano and a Macbook Pro laptop (Snow Leopard OSX 10.6.2) My problem is Audacity is not detecting the device (Roland Digital Piano). You can see from that, that this is a device from Arduino.Hi, I've had a good hunt through posts and tried as much as I can to solve this, but looks like I need additional help. 'IOGeneralInterest' = 'IOCommand is not serializable' 'USB Vendor Name' = 'Arduino ('Device Speed' = 1 'IOUserClientClass' = 'IOUSBDeviceUserClientV2' Disregarding the other devices the last entry for me was: +-o Now try again adding -l (that's a lower-case L) to the command line. The last one in my case was the one that appeared when I plugged in the Uno.

Try listing your USB devices before and after plugging in the Arduino by typing (in the Terminal): ioreg -p IOUSB -w0

This is too long for a comment so I'll make it an answer.

Mac not detecting usb serial