Robopoly’s JIG kit : Building a Fully Wireless Robotic Arm from Scratch

We are Robopoly, the makerspace and robotics club of EPFL (École Polytechnique Fédérale de Lausanne), entirely run by students. Our mission is to make robotics and electronics accessible to everyone, from total beginners to seasoned makers, by providing tools, guidance, and hands-on kits that members build themselves.

One of our latest projects is the Kit JIG, originally designed for the Journée d’Information des Gymnasiens (a high school outreach event held at EPFL) and now available to all our members. It is one of the 2 most complete educational kits to date (with the Botanical Kit), covering mechanics, electronics, and programming in one single build.

What is the JIG kit ?

The Kit JIG is a fully wireless, 5-degree-of-freedom robotic arm controlled by a custom-built handheld controller. The whole system revolves around two custom PCBs:

The controller PCB : featuring an ESP32-S3 implemented from scratch, two analog joysticks, a full Battery Management System (BMS) with TP4056 charger, DW01A cell protection, FS8205A dual-MOSFET, and an MT3608 boost converter to run the system from a single 18650 Li-ion cell.
The arm PCB : featuring a second ESP32 for Wi-Fi/BLE communication with the controller, along with five servo motor ports to drive each joint of the arm independently.

The two boards communicate wirelessly, making the setup fully cable-free during operation. The arm itself gives members hands-on experience with 5-DOF kinematics: four articulated joints plus a gripper, assembled from a mechanical kit.

An optional Console extension transforms the controller into a game console, adding an OLED screen, haptic feedback motors, and extra buttons to run games like Pong, Snake, or even a multiplayer DOOM.

Where Eurocircuits Made the Difference ?

Our members solder every component themselves, step by step, guided by detailed assembly instructions. For this to work, the boards have to be reliable and precisely manufactured. Both the controller PCB and the arm PCB were manufactured by Eurocircuits, and the quality showed immediately during assembly. Pads were clean, soldermask registration was precise, and the silkscreen was perfectly legible, details that matter enormously when members are soldering fine-pitch SMD components like the FS8205A or the TP4056 for the first time. Having professionally manufactured PCBs meant we could focus entirely on the pedagogical experience, rather than debugging manufacturing defects.

What’s Next ?

The Kit JIG is now part of Robopoly’s permanent catalogue, available to all members. We are already working on firmware improvements and new extensions. Thanks to Eurocircuits, we have a solid hardware foundation to build on, and a kit we are genuinely proud to put in the hands of our members.

For more information, visit Robopoly’s website or the Kit JIG page.