Smart Breadboard: Remote Electronics Laboratory
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Smart Breadboard (2020–2021) is a remote electronics laboratory built by Team Circuitus at the University of Moratuwa during the pandemic, when students lost access to physical labs.
A student draws a circuit on a 2D breadboard model in a web application, and the system physically reconstructs it in the lab: the server forwards the requested connections to a microcontroller, which drives a switching matrix that wires up a real breadboard. Instruments such as a voltmeter, ammeter, and function generator can be switched into the circuit the same way, so students take real measurements on real components from home.
Hardware
The core of the system is a solid-state-relay switching matrix that makes and breaks connections between breadboard lines.
- Solid-state relays (LH1525AT) supporting AC and DC operation, with 0.13 ms switching time and up to ±100 V.
- SN74HC595 shift registers perform serial-to-parallel conversion so the microcontroller can drive the whole matrix with a handful of pins.
- Two 16×6 switching matrices supporting practicals up to ±15 V and 100 mA, with under 50 ms response to a new connection.
- Proof of concept on a custom-etched PCB with an Arduino, with an ESP32 (NodeMCU) and Bluetooth link in the final design.
- Costed for mass production at roughly US$80 per unit.
Software
A Node.js/Express web application with a MongoDB backend runs the laboratory end-to-end:
- Live lab sessions: instructors schedule and supervise practicals; students join, build their circuit on the interactive breadboard view, and submit their work.
- Role-based accounts for students, instructors, and admins, including registration, session management, device activation, and marking of submissions.
- The server validates each requested connection, computes the relay path, and sends it to the microcontroller, which acknowledges the physical connections made.
Recognition
The project won first place (Sri Lanka) at the IEEE PES remote-lab design competition and advanced to the Region 10 stage of the IEEE CAS Student Design Competition.