Simple robot projects always seem interesting/fun. Archive: https://archive.today/Gtn0O From the post: >>[Paul McCabe] wrote in to let us know about his $25 robot. This small wheeled robot is based on an ESP32 and made using cardboard and hot glue. You drive the contraption using a Bluetooth game controller thanks to the Bluepad32 library, which boasts a long list of supported hardware. [Paul] provides a Bill of Materials (BoM), complete with current component pricing. We don’t know about you, but it struck us as funny that the microcontroller is less expensive than the battery! Ah, the times we live in. Also [Paul] assumes you already have an appropriate Bluetooth controller and doesn’t include that in the total cost.