---
title: "MQTT using wiz820io on mbed"
url: "https://maker.wiznet.io/forum/12046"
markdown_url: "https://maker.wiznet.io/forum/12046/md"
type: "Forum topic"
category: "IO Modules"
author: "paultanner"
created: "2016-12-02T16:08:24+09:00"
last_activity: "2017-05-04T08:39:27+09:00"
language: "en"
views: 1033
replies: 0
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# MQTT using wiz820io on mbed

## Question

Asked by paultanner on 2016-12-02 in IO Modules.

I’ve been trying to build the above without success.
I tried a simple example of using the WIZnet_Library and that works OK.
To get this working over MQTT I tried importing IBMIoTClientEthernetExample_WIZnet which is close to what I want to do.
However, this throws a number of fatal errors which appear to be due to changes since this example was created. e.g.
e.g. Error: No default constructor exists for class “EthernetInterface” in “MQTT/MQTTEthernet.h”, Line: 24, Col: 6
Does anyone have a working example that I can use as a starting point?
Thx.

PS. The other example using WizNet and MQTT “MQTTw7500” throws the same error. It could be that the WizNet Library has changed.

---

Source: https://maker.wiznet.io/forum/12046