We present the design of an inexpensive and reliable mechanical laser shutter and its electronic driver. A camera diaphragm shutter unit with several sets of blades is utilized to provide fast blocking of laser light and protective shielding of the shutter mechanism up to a laser beam power of 1 W. The driver unit is based on an Arduino microcontroller with a motor-shield. Our objective was to strongly reduce construction effort and expenditure by limiting ourselves to a small number of modular parts, which are readily available. We measured opening and closing durations of less than 800 μs, and a timing jitter of less than 25 μs for the fastest set of blades. No degradation of the shutter performance was observed over 5·104 cycles.