ESP32 Röle Kontrol Kartı

In progress

An ESP32 relay control board that switches four separate loads, with every channel isolated by an optocoupler. The schematic is done; PCB layout is in progress.

ESP32
Relay
Optocoupler
CH340C
Altium Designer

Project

3D draft view of the ESP32 relay board: ESP32 module and USB-C at the top, four blue relays with screw terminals at the bottom

A 4-channel relay control board built around an ESP32. Each channel switches its own independent load, and the ESP32's Wi-Fi and Bluetooth will let the board be controlled remotely. The board can be both powered and programmed over USB-C.

Circuit

Main controller: ESP32-WROOM-32E (16 MB flash)
Programming: a CH340C USB-to-serial converter and an automatic boot/reset circuit with two SS8050 transistors, so no buttons are needed to upload code; EN and BOOT buttons are still there
Protection: SM712 TVS diode for ESD protection on the USB data lines
Power: LM1117 regulating 5 V down to 3.3 V, plus a power LED
On every relay channel: a PC817 optocoupler isolating the ESP32 from the relay side, an SS8050 transistor relay driver, a 1N4007 flyback diode and a status LED
Outputs: a screw terminal with COM / NC / NO for each relay
Expansion: UART, I2C (with 4.7 kΩ pull-ups), SPI and power connectors

Status

The schematic is finished in Altium Designer (October 2026, revision V1). The 3D view above is a draft of the component placement; the next step is routing the PCB and manufacturing the board.