We caught a glimpse of this Basic Stamp 2 controlled electronic slot machine on YouTube. We’re very grateful that [Mike Donahue] was willing to share more about his project with us.
He uses tactile switches instead of dropping coins in a slot, and a lever-style switch sets the one-armed bandit in motion. The action is displayed on a 1.5″ µOLED-128-G1 screen that has its own controller (which explains how this operates so well with the relatively slow BS2). For realism there’s some pretty good sound effects provided by a piezo speaker. We’ll look at the code, graphics, and some video after the break.
The connections are quite simple and [Mike] has built the project on the Basic Stamp 2 Homework Board. The display is addressed through two serial lines and a reset pin.
He generated the graphics using MSpaint, creating three full screen images that rarely change. The icons for the spinning dials are much smaller and overlayed on top of the larger images. Three of these icons are stored next to each other in memory. That way, a pointer can be advanced and the next image will start to scroll in, resembling a spinning cylinder. Here’s a bit larger version of the schematic and images if you need it.
This makes for a fun toy and it’s quite well executed. If you’re interested in taking a look under the hood, here’s a copy of the source code.