MQTT stands for Message Queue Telemetry Transport. It's a protocol designed for low-bandwidth, high latency networks. You can learn more about it here.

The Bluefruit LE Connect App allows you to send and receive data using the MQTT protocol. This may be useful for making sensor readings from a Bluefruit device viewable on the web.

Configuration

You will need an adafruit.io account in order to log and collect your data. You can make one here.

• To learn more about adafruit.io, check out the guide for it here.

Once you have your Adafruit IO account set up, connect to your device using the Bluefruit LE Connect app. Tap the UART mode.

In the UART module, tap the MQTT button at the top of the screen.

Change the Address to io.adafruit.com. Set the Port to 1883.

Before filling in the necessary information, you will need to create 3 feeds on your adafruit.io account: rx, tx, and output.

• If you do not already know how to create a feed, head over to Adafruit IO Basics: Feeds.

You are also going to need your Adafruit IO username and secret API key.

Navigate to your profile and click the View AIO Key button to retrieve them. Write them down in a safe place, you'll need them for the next step.

Under ADVANCED, enter your Adafruit IO username and key.

Usage

Here are some examples of feeds created using the Bluefruit LE Connect app in the same manner as described above.

Received Data

This is an example of an RX feed that presents data sent from an Adafruit Feather Bluefruit and is received by iPhone using the Bluefruit LE Connect app via MQTT. The data is sent using an ASCII Numeric format similar to how plotter data is sent. You can see the plotter feature here.

Written Data

This is an example of a TX feed that presents data sent from the Bluefruit LE Connect app to adafruit.io via MQTT.

Output Data

This is an example of an output feed that presents data created on adafruit.io sent to the Bluefruit LE Connect app via MQTT