Means again in 2005, Jan acquired a LEGO 4511 practice set as a Christmas present. That nifty little package is an electrical mannequin railroad, however with LEGO’s trademark blocky user-assembled twist. Jan performed with that practice set for years, however ultimately he acquired older and it ended up in storage for a decade, just like the bittersweet starting of a Pixar film. Quick ahead to the current and Jan is all grown up with some maker abilities below his belt. With vacation cheer in his coronary heart, he utilized these abilities to give the LEGO 4511 practice set a Christmas ESP32 improve.
Like most mannequin railroads, the unique LEGO 4511 practice set labored by supplying DC energy to the practice engine via the rails. One rail is optimistic and the opposite is floor. The practice engine has a DC motor that completes the circuit and the controller lets the conductor regulate voltage, thereby rising or lowering pace. To maneuver the practice backwards, the controller reverses the polarity via the rails.
Jan’s improve utterly alters that complete working precept. As a substitute of receiving energy via the rails, the upgraded practice is self-contained. It carries its personal lithium battery pack to energy the unique DC motor and an ESP32-based NodeMCU growth board controls that via a DRV8833 twin H-bridge drive. Jan paired the 18650 lithium battery with a battery administration system and a TP4054 charging module. A touch of WS2812B RGB LED lighting gave the practice that coveted Christmas aptitude.
The person can management the practice with their smartphone via a Bluetooth connection. That’s accomplished with a easy terminal app that sends JSON serial instructions. Jan additionally built-in a form of brick-based positioning system, so the practice can cease at predetermined bodily areas that set off a contact sensor. That lets the practice robotically depart the bar station and transfer alongside till it reaches the thirsty buyer station, the place it might cease lengthy sufficient for individuals to seize their photographs.
Jan wished this upgraded practice to ship photographs, however discovered that their weight overloaded the small LEGO motor. Sooner or later, he plans to present the practice extra oomph and extra energy to go together with that.
These challenges ought to give Jan an excuse to play along with his LEGO practice set for at the very least one other vacation or two.