I'm having a problem using the CanaKit USB Relay board with Win7 64-bit.
I've written a python class to control this board and it works great under Linux and WinXP. However, under Win7 64-bit it appears to occasionally drop characters.
Under Win7, when I compare the string sent to the board to the string that is echoed back, there are occasionally characters missing from the echoed string, and of course, the board does not perform the function that was requested.
I'm running a Linux (Xubuntu 12.04) virtual machine under VMWare on my Win7 64-bit host computer. Running the Python code on the Linux VM works flawlessly. Running the Python code on the Win7 64-bit host computer gives the above described behavior. Running the Python code on another computer with WinXP (32-bit) works flawlessly.
Since all of the hardware (PC and relay board) in the Linux and Win7 examples is exactly the same, I feel comfortable in saying the hardware is functioning properly.
I've tried inserting inter-character delays, and inter-command delays (up to 2 seconds) to no avail.
This board uses the built-in windows usbser.sys CDC driver with a manufacturer supplied INF file. The driver is installed, the device is detected and enumerated and communicates, but as described above, appears to drop characters sporadically.
I submitted this issue to CanaKit via their web form, but have received no reply from them.