OK now that your online MQTT broker stuff is all set up, you can get your electronics ready

If you don't have any electronics...

You can also use your computer to play around with feeds! Check out this MQTT.fx tutorial for desktop client usage

Install Adafruit_MQTT

In order to 'talk' MQTT, we'll use the Adafruit MQTT library. It works with any MQTT broker and frankly we think its the best low-footprint library out there. The library's code is stored here and you can download it via the Arduino library manager.

Open up the Arduino library manager

Search for the Adafruit MQTT library and install it

We also have a great tutorial on Arduino library installation at:

First Test

We'll be using an Adafruit Feather Huzzah ESP8266 devboard for this demo.  You can also use a HUZZAH ESP8266 + FTDI cable.

To start with, we won't be connecting any sensors or anything.

Load up example

OK depending on which one you picked, load up the Arduino IDE and select the matching example. For ESP8266 pick mqtt_esp8266

before uploading, you need to set up a few things.

Connection pinouts

If you're using the ATWINC1500 or whatever, check to make sure these pins are correct!

/************************* ATWINC1500 Pins *****************************/
#define WINC_CS   8
#define WINC_IRQ  7
#define WINC_RST  4
#define WINC_EN   2     // or, tie EN to VCC

Set up WiFi credentials

Dont forget you need to tell the Arduino how to connect to your local network, so set up the WiFi credentials:

/************************* WiFi Access Point *********************************/

#define WLAN_SSID       "...your SSID..."  // can't be longer than 32 characters!
#define WLAN_PASS       "...your password..."

Finally, set your adafruit.io username (hey you remember that from the last chapter right?) and adafruit.io key

#define AIO_SERVER      "io.adafruit.com"
#define AIO_SERVERPORT  1883
#define AIO_USERNAME    "...your AIO username (see https://accounts.adafruit.com)..."
#define AIO_KEY         "...your AIO key..."

NOW you can upload the sketch to your Arduino or ESP8266.

Publication test

Open up the serial console as soon as the sketch is done uploading. You'll see something like this (I'm using an ESP8266 here)

Now click back to your Adafruit IO dashboard, the one you made before. You'll see the photocell gauge clicking upwards

You can mouseover the gauge to get the last updated timestamp. And at the top of the page you'll see what looks like a bunch of blue dots. Those dots tell you that you've had data transferred in or out of your feeds, handy to get a quick sense of whether new data is streaming in!

And, if you go back to your feeds page, you can see each value as it comes in, as well as download a spreadsheet if you like

Subscription Test

OK you have data going from your device to adafruit.io but wouldn't it be nice if you could have signals going back as well? No problem! Lets use our onoff feed, we're already subscribed to it.

While keeping your serial console open, click on the slider button in your dashboard

In the serial console, you'll see those messages are received:

the updates from button flip to message appearing should be under 1 second, showing the speed of MQTT!

This guide was first published on Jan 14, 2016. It was last updated on Mar 08, 2024.

This page (Arduino+Library Setup) was last updated on Mar 08, 2024.

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