A well-equipped electronics lab is crammed with power supplies, measuring devices, test equipment and signal generators. Wouldn't it be better to have one compact device for almost all tasks? Based on the Arduino, a PC interface is to be developed that's as versatile as possible for measurement and control. It simply hangs on a USB cable and — depending on the software — forms the measuring head of a digital voltmeter or PC oscilloscope, a signal generator, an adjustable voltage source, a frequency counter, an ohmmeter, a capacitance meter, a characteristic curve recorder, and much more. The circuits and methods collected here are not only relevant for exactly these tasks in the "MSR" electronics lab, but many details can also be used within completely different contexts.