Building a Wired Cab Intercom From Scratch

The Challenge

A US client wanted a wired communication device for a cab: a driver module and a passenger module. One side works as push-to-talk and the other is always active. He had the idea but no hardware, firmware or enclosure.

What We Did

• Enclosure: designed and 3D-printed it
• Firmware: wrote it for the ESP32-S3
• Prototype: built and verified the circuit on a breadboard first
• PCB: designed the custom board and fitted it inside the enclosure
• Hardware: microphone, speaker, button and LED in each module, with the two modules communicating over UART
• Testing: tested in a real car environment, then shipped to the client in America

The Result

The client confirmed the device works well in a real car.

Specs