My youngest come with an idea to build a “Shopkins vending machine”. A quick build, not much structure to it, but great fun.
Waiting to unbox some of the HexBug VEX kits I bought today (hint: VEX Holiday promotion +20% off at Toys!) so we can replace some of the front panels with the transparent ones.
For video, see: - YouTube
If we have a bit of time tomorrow, we may add actual coin drop sensor instead of the TouchLED
Now with the coin drop: VexIQ Shopkins vending machine - YouTube
It uses color sensor in grayscale mode against a very bright backdrop. Works well with pennies, though I haven’t really tested it with shiny silver coins.
I was afraid the sensor won’t be fast enough to register the falling coin (the brain is plenty fast, but it only queries the sensors every so often), but it works 100%
I had to line the coin path with paper, otherwise coins could easily get stuck. The paper also forms an insulated optical chamber, so the sensing is robust, regardless of external light.
Next time, I’d build a vertical coin slot so the coin would roll through, maybe forming an optical gate with color sensor passive and light provided by TouchLED…