Universal Wi-Fi Controller Board Although LED control systems exist in many shapes and sizes, surely there’s room for one more from Elektor. Next month we’ll publish a handy circuit that allows an RGB LED strip to be controlled through a Wi-Fi network. Those of you tired of seeing yet another RGB LED circuits will like the extra features built into the project, like a boot loader, an expansion port and protective diodes. The circuit is easily adapted for Wi-Fi based control of a garage door, a bunch of relays, a robot, a (model) car or even a train. Lithium-ion Battery Charger Properly recycling Lithium-ion batteries and battery packs from junked equipment is not easy because the batteries are usually charged internally, i.e. by the equipment itself. Consequently there is no separate charger that can be recycled also. But then, it is not difficult to build a charging circuit for used (or new) Li-ion cells. This circuit is microcontroller free, and instead employs a special charger IC from Maxim. An array of LEDs indicates the charging progress. Article titles and magazine contents subject to change;