The ESC3B04 is a compact DIN rail-compatible relay board built around the ESP32-C3 Super Mini module for building Wi-Fi remote switches, voltage monitoring systems, motor control, timed automation, and RS-485-based setups.
The board features four 10A relay outputs, four 0–5V/10V analog voltage inputs (also configurable as 12–24V PNP digital inputs), an RS-485 interface, and a push-button input. It operates on a 7–25V DC supply and supports direct installation in control panels or DIN-rail enclosures.
ESC3B04 relay board specifications:
- Wireless module –16-pin ESP32-C3 Super Mini module
- SoC – Espressif Systems ESP32-C3FH4, single-core 32-bit RISC-V microcontroller @ up to 160 MHz; 400 KB SRAM; 4MB flash
- USB – 1x USB Type-C port for programming
- Ceramic antenna
- I/Os and expansion
- 4x relays (10A/240VAC)
- 4x 0-5V/0-10V analog voltage inputs (can be used as 12-24V digital inputs)
- Serial – RS-485 interface for Modbus or custom protocol communication
- Misc
- User button
- Power LED
- Power Supply
- 7-25V DC wide range supply voltage via terminal block
- Current consumption
- Standby – 15mA
- 1 relay ON – 74mA
- 2 relays ON – 106mA
- 3 relays ON – 131mA
- 4 relays ON – 164mA
- Dimensions – 77 x 72 x 19 mm (board only)
- Weight – 80 grams (board only), 144 grams with DIN enclosure
The company mentions that the ESP32-C3 board can be programmed with the Arduino IDE, ESP-IDF framework, or PlatformIO. No code is provided, so the users have to program RS-485, Wi-Fi control, and automation logic by themselves.
Previously, we have written about other Espressif-based relay boards like the XIAO 6-Channel Wi-Fi 5V DC Relay Board, the ESP32 IoT Relay Board” credit card-sized quad relay board compatible with Tasmota, and the Olimex ESP32-C6-EVB, out of which the Olimex board is most feature-rich and integrates Wi-Fi 6, BLE 5.0, and Zigbee/Thread via the ESP32-C6, and includes 4 opto-isolated digital inputs, 4 relays, USB-C for programming, and more.
The ESC3B04 industrial relay board is available with the ESP32-C3 Super Mini module on AliExpress for $12.27 or $12.84 with the DIN rail mount. More information about the product can be found on Eletechsup’s product page.
Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
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