---
title: "Relay Driver Board, 21 Channels, 12V, Arduino 2560 shield, Node Red, MQTT, W5100 Ethernet"
url: "https://maker.wiznet.io/mathad/projects/Relay-Driver-Board-21-Channels-12V-Arduino-2560-shield-Node-Red-MQTT-W5100-Ethernet/"
markdown_url: "https://maker.wiznet.io/mathad/projects/Relay-Driver-Board-21-Channels-12V-Arduino-2560-shield-Node-Red-MQTT-W5100-Ethernet/md"
type: "UCC: User Created Content"
author: "mathad"
author_url: "https://maker.wiznet.io/mathad/"
original_author: "mathad"
original_url: "https://youtu.be/ZOzFaQZjA94"
published: "2021-03-02"
language: "en"
hardware: ["Arduino 2560 Mega", "WIZnet W5100 ethernet shield", "Raspberry Pi Zero"]
likes: 0
views: 620
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# Relay Driver Board, 21 Channels, 12V, Arduino 2560 shield, Node Red, MQTT, W5100 Ethernet

> Relay Driver Board, 21 Channels, 12V, Arduino 2560 shield, Node Red, MQTT, W5100 Ethernet

Original author: mathad (source: https://youtu.be/ZOzFaQZjA94)

## Components

- **Arduino 2560 Mega** x 1
- **WIZnet W5100 ethernet shield** x 1 ([docs](https://www.wiznet.hk/en/open-source-hardware/102-w5100s-ethernetshield.html?search_query=W5100+ethernet+shield&results=84))
- **Raspberry Pi Zero** x 1
- Software: **Arduino**
- Software: **EasyEDA Project**

## Documents and links

- [PubSubClient Library](https://github.com/knolleary/pubsubclient) (code)
- [Arduino Sketch](https://github.com/dusnoki/arduino-mqtt-21-channel-relay-driver) (code)

## Article

Original link: https://youtu.be/ZOzFaQZjA94

---

Source: https://maker.wiznet.io/mathad/projects/Relay-Driver-Board-21-Channels-12V-Arduino-2560-shield-Node-Red-MQTT-W5100-Ethernet/