---
title: "WiFi to GPIO/Relay and DAC outputs board"
url: "https://maker.wiznet.io/mhanuel/contest/wifi-to-gpio-relay-and-dac-outputs-board/"
markdown_url: "https://maker.wiznet.io/mhanuel/contest/wifi-to-gpio-relay-and-dac-outputs-board/md"
type: "Contests"
author: "mhanuel"
author_url: "https://maker.wiznet.io/mhanuel/"
original_author: "Manuel Iglesias"
license: "GNU Lesser General Public License version 3 or later (LGPL3+)"
published: "2022-10-30"
language: "en"
hardware: ["WIZnet WizFi360-EVB-Pico"]
likes: 8
views: 2623
comments: 5
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# WiFi to GPIO/Relay and DAC outputs board

> A GPIO/Relay/DAC card controlled by WIzFi360 module using MQTT.

Original author: Manuel Iglesias

## Components

- **WIZnet WizFi360-EVB-Pico** x 1
- Software: **MQTT**

## Documents and links

- [circuitpython and Flask App sources](https://github.com/mhanuel26/Relay-Flask-MQTT-WizFi360) (code): Source for testing the Relay board using MQTT and Flask.
- [Schematics PDF files](https://maker.wiznet.io/_lib/download.asp?path=project/1828&downfile=output%2Epdf) (schematics): Board schematics

## Article

The project is a GPIO /Relay and DAC board using WIzFi360.

![](https://maker.wiznet.io/upload/ckeditor5/797178031%5F1667146699%2Ejpg)

The board has 8 relays outputs connected to an 8-bit GPIO extender controlled by I2C bus from Raspberry Pi PICO.

The board has an advance GPIO IC P/N CY8C9520A-24PVXIT controlled as well by I2C.

There is a 8 channel DAC by Microchip P/N MCP48CMB28-E_ML controlled by SPI interface.

To test the WizFi360 I decide to use circuitpython. I was trying to get websockets working but looks there is not a library yet for WizFi360, so in the meantime I use MQTT.

Here is a video controlling an LED using the Relays from an HTTP page hosted by Flask framework. There are a couple of LED, one is connected to a DMM for easy viewing the voltage level.

[Embedded media](https://www.youtube.com/embed/Nrh5TgafToM)

The Flask app connects to a mosquitto MQTT server and publish changes to Relay states. The WizFi360 is connected and suscribed to relay topic. It received notifications and change Relay states.

The MQTT circuit python library used is

<https://github.com/ronpang/WizFi360-cpy>

The GPIO extender library used is located here

https://github.com/milador/Community_CircuitPython_TCA9534

The board presented a couple of issues that were fixed by prototyping it. The design was made under KiCAD and here is a 3D view.

![](https://maker.wiznet.io/upload/ckeditor5/797178031%5F1667152070%2Ejpg)

![](https://maker.wiznet.io/upload/ckeditor5/797178031%5F1667152084%2Ejpg)

The project is a work in progress to provide functionality to the rest of the components in board as well as new connectivity options.

---

Source: https://maker.wiznet.io/mhanuel/contest/wifi-to-gpio-relay-and-dac-outputs-board/