For our local community theatre group in Sydney, we are currently putting on the musical LITTLE SHOP OF HORRORS about the man-eating plant that comes to New York to take over the world.


As part of the production, to show long boring days in the florist shop, it requires an analog clock to be spun quickly to show passing of time.


Rather than designing to motor control circuit from basic electronics, I had the great idea to use a Lego Mindstorms EV3 robotics kit to drive the motor.


I soldered a 9 Volt power supply permanently to the Lego Power Brick controller as 6 AA batteries would not last the length of the show.


On the back of the clock there is the little knob that you use to set the time by hand. I was able to file down an "x" shaped lego piece to tightly pit inside this knob's drive shaft to connect from the Lego servo motor to the clock.


Knowing that Lego Mindstorms hardware runs using LabVIEW code, I then went about writing a LabVIEW routine to drive the clock from a list of cues as the show requires.


The laptop connects to the Lego brick via Bluetooth which allows the operator to sit anywhere in the hall to control the clock during a performance. The clock can be manually controlled via the laptop to set any time and move the hands backwards or forwards in time with varying speed, or it can run the next cue that sets to clock to a specific time of the day!


So while the Audrey II plant is munching on the cast, my clock project is happily running away driving the analog clock like magic!


Shown here are the two smaller puppets, it keeps getting bigger and bigger as it eats more body parts! Great fun for Halloween!!


Adam Wilson 

Little Shop of Horrors runs in Eastwood Sydney from 26 Oct to 10 Nov, 2018.