I'm on *that* wavelength. I recently built a shutter controller to ship with one of our spectrometers. I also built a small test box to determine if any given problem might be with the controller or with whatever device was driving the controller. I heard later that there was some problem which our "customer" spent half a day to discover that the controller was OK and the problem was elsewhere. The tester would have isolated the error in less than a minute, but they couldn't be bothered with finding the tester. Oh well.
(so many nodes and so little time ... )