WSAL11638 – RPi Relay Board/en

Documentation notice: This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.

Product view RPi Relay Board — RPi Relay Board

Catalog location in the JW Tech Shop:

WSAL11638 – RPi Relay Board: AI → Expansions → Motors / Relays / SCR; Misc Modules → Others → Power / Relays / SCR; Raspberry Pi → HATs → Motors / Relays / SCR

Summary

The RPi Relay Board is a Raspberry Pi expansion board with three relay channels driven via GPIO pins. It allows switching external loads through NC/NO contacts and provides demos in shell, C (bcm2835/wiringPi), Python, and web-based control.

Related products at JW Tech

WSAL11638 – RPi Relay Board

Technical overview

Three relay channels (CH1–CH3) map to RPi pins P25 (BCM 26), P28 (BCM 20), and P29 (BCM 21).
The Relay_JMP jumper must be installed for the Raspberry Pi to control the relays.
Relays are low-level triggered: a Low output lights the corresponding LED, closes the NO contact, and opens the NC contact.
Each channel has a screw terminal block with three pins for connecting external circuits.
When cabled instead of stacked on the pin header, connect 5V, 3.3V, and GND for power.
Multiple boards cannot be stacked due to relay height; they can be daisy-chained with Dupont cables.
The demo package includes shell, C (bcm2835/wiringPi), Python, and web-control scripts accessible on port 8080.
If the control signal appears inverted or no response occurs at high level, it is because the relay activates on a low signal.

Commands and examples – verify before use:

sudo ./Relay.sh CH1 ON
sudo ./Relay.sh CH2 ON
sudo ./Relay.sh CH3 OFF
make
sudo ./Relay_Module
sudo python Relay_Module.py
python3 main.py

Notes and version constraints

Library versions (e.g., wiringPi 2.52 vs. 2.70) depend on the OS version; verify before installing.
Web control requires Google Chrome; other browsers may be incompatible.
After running the Python demo on VisionFive2, pins may become unresponsive — restart or run clear.sh.
Specific voltage values, certifications, or warranty details are not provided in the source; do not invent them.

Source and revision record

RPi Relay Board - Waveshare Wiki
Source revision: 69155
Captured: 2026-08-29T08:10:01+00:00
SHA-256: 143f5493878f5bf4460435c0fcba1c1ada7210c93c1f04fb4fabf449de784e31