Olimex PICO-EVB board for the Raspberry Pi Pico and compatible boards is designed for high-voltage automation with four 3.3-30V DC or 110-220V AC inputs and four 15V DC/220V AC relays.
It features two 20-pin headers enabling users to connect their preferred Pi Pico-compatible board, a USB-C port for power and programming, a UEXT connector for I2C, UART, and SPI expansion, and status LEDs for the high-voltage signals.
Olimex PICO-EVB specifications:
- Compatible boards
- Raspberry Pi Pico, Pico 2, Pico W, Pico 2 W
- Olimex RP2040-PICO30
- USB – 1x USB Type-C port
- I/Os
- 4x 15A 24V DC/240V AC relays
- 4x optoisolated inputs taking 3.3 – 30V DC or 110-220V AC
- UEXT connector with I2C, UART, and SPI signals
- Unpopulated 18-pin GPIO header
- Misc
- 4x status LEDs for the relays
- 4x status LEDs for the inputs
- Power Supply – 5V power supply via screw connector, USB-C port, or Pico’s micro USB connector
- Dimensions – 100 x 70mm
- Temperature Range – -45°C to +85°C
As with most Olimex boards, the PICO-EVB is an open-source hardware board with the KiCad hardware design files released on GitHub. The repo also includes ready-to-use Arduino and MicroPython code samples, which poll the inputs and control the relays. One of the Micropython samples runs a web server to allow users to access an interface from a web browser to display the status of input pins and control the relays. Finally, it should not come as a surprise that the company also provides a YAML configuration for ESPHome firmware, enabling Home Assistant automation framework support.
The PICO-EVB board is far from being the first Raspberry Pi Pico or RP2040/RP2350 board to add support for relays, and other boards include the Waveshare RP2350-Relay-6CH with six relays, RS485, Pico HATs support, and 7-36V DC input, and 8086 Consultancy’s PicoRelay8 with eight relays. However, it’s harder to find boards with both relays and high-voltage inputs, although one competitor is the Piromoni Automation 2040 W, offering a different set of features.
Olimex sells the PICO-EVB board for just 14.95 Euros, or about $17 US, on its online store. You’ll just need to add your own Pico board.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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Olimex has good pricing except for shipping (€25).
In the past there was a way to choose post instead of courier service, but I’m not sure if that is still available, best to check with Tsvetan.
110-220V AC Input next to 5V/USB.
Thats bad 🙁
I was wondering about the 220V inputs, as most of the world has 230 or even 240V nowadays.
So I checked Olimex and same specs, then the schematic:
30V: 3.9k resistor
220V: 2x 150k resistor
Lets assume led and optocoupler drop around 3V that gives about 7mA input current at 30V and 0.7mA at 220V
If I didn’t get anything wrong then it would be good for 2200V 😁
The relays are rated 15 Amps not 15 V, should state 4x 15A 24V DC/120V AC relays.
But no 24V DC supply input, no DIN rail mounting, no RS-485. Will wait for next revision.
Other similar competitor also include M5Stack StamPLC (with ESP32).