ThingSpeak IoT Blog

Create and Train a Feedforward Neural Network

We have published an example in the ThingSpeak documentation that shows you how to train a feedforward neural network to predict temperature. The feedforward neural network is one of the simplest types of artificial networks but has broad applications in IoT. Feedforward networks consist of a series of layers. The first layer has a connection from the network input. Each other layer has a connection from the previous layer. The final layer produces the network’s output. In our IoT application, the output will be the predicted temperature.

IoT Application

We are collecting data in a ThingSpeak channel and will use the integrated MATLAB analytics. To predict the temperature, this example makes use of the Neural Network Toolbox in MATLAB along with the data collected in a ThingSpeak channel. We will be using data collected by a weather station located at MathWorks offices in Natick, Massachusetts.

The process for creating, training, and using a feedforward network to predict the temperature is as follows:

  1. Gather data from the weather station
  2. Create a two-layer feedforward network
  3. Train the feedforward network
  4. Use the trained model to predict data

Read Data from the Weather Station ThingSpeak Channel

ThingSpeak channel 12397 contains data from the MathWorks weather station, located in Natick, Massachusetts. The data is collected once every minute. Fields 2, 3, 4, and 6 contain wind speed (mph), relative humidity, temperature (F), and atmospheric pressure (hg) data respectively. To read the data from the weather station within MATLAB, use the thingSpeakRead function.

data = thingSpeakRead(12397,'Fields',[2 3 4 6],'DateRange',[datetime('Jul 30, 2018'),datetime('Jul 31, 2018')],...

Create Two-Layer Feedforward Network

Use the feedforwardnet function to create a two-layer feedforward network. The network has one hidden layer with 10 neurons and an output layer.

net = feedforwardnet(10);

Train the Feedforward Network

Use the train function to train the feed-forward network.

[net,tr] = train(net,inputs,targets);

Use the Trained Model to Predict Data

After the network is trained and validated, you can use the network object to calculate the network response to any input.

output = net(inputs(:,5))
output =


This example can be adapted to other IoT applications. Check out the ThingSpeak documentation for the code and explanation.

Introducing ThingSpeak Gauges!

The ThingSpeak IoT has been building a new framework to support widgets on channel views. Widgets can be added to the public or private view of a ThingSpeak channel and even be embedded in 3rd-party systems and dashboards. The first widget that we are releasing is the gauge!

At the recent Boston TechJam, MathWorks had a ThingSpeak People Counter that used face detection to count people that came over to our booth and learned about our demo. The people counter uses MATLAB to identify faces in a live video stream from a webcam, count the number of faces, and send the results to ThingSpeak. The code and instructions for the ThingSpeak People Counter project are on File Exchange.

I used the new ThingSpeak gauge widget to show the visitors the lastest people count. The gauges are easy to set up, you don’t have to edit JavaScript code, just point-and-click and configure options. You can add custom colored ranges, units, and display options. If you want to learn more about ThingSpeak channel display widgets and gauges, visit the MathWorks Documentation for ThingSpeak.

Now that we have the infrastructure for widgets on ThingSpeak, we can more widget types. What other widgets would you like to see on ThingSpeak?


ThingSpeak Now Supports the Predictive Maintenance Toolbox for MATLAB

The ThingSpeak team has integrated the Predictive Maintenance Toolbox for MATLAB into the IoT Analytics features of ThingSpeak. The Predictive Maintenance Toolbox provides tools for labeling data, designing condition indicators, and estimating the remaining useful life (RUL) of a machine. You can analyze and label machine data imported from local files, cloud storage, and distributed file systems. You can also label simulated failure data generated from Simulink models.

Here is a quick list of features of the Predictive Maintenance Toolbox for MATLAB:

  • Survival, similarity, and time-series models for remaining useful life (RUL) estimation
  • Time, frequency, and time-frequency domain feature extraction methods for designing condition indicators
  • Organizing sensor data imported from local files, Amazon S3™, Windows Azure® Blob Storage, and Hadoop®Distributed File System
  • Organizing simulated machine data from Simulink® models
  • Examples of developing predictive maintenance algorithms for motors, gearboxes, batteries, and other machines

The Predictive Maintenance Toolbox is available on ThingSpeak to users that have a license to the toolbox. Just sign into ThingSpeak using your MathWorks Account and you will have access to the features of the Predictive Maintenance Toolbox with the MATLAB Analytics app. If you have any questions about the Predictive Maintenance Toolbox, contact Aditya Baru at MathWorks.

Organize Your ThingSpeak IoT Channels with Tags!

I am excited to announce a number of new features that are available to all ThingSpeak users. We added the ability for ThingSpeak channels to be organized by tags. ThingSpeak channels have a “tags” setting that allows you to enter some tags separated by a comma. I use them to organize my channels by a project identifier. In some of my projects, I need a few channels to represent the system. By tagging both channels with the same project identifier, I can see the related channels. We have added a search box to help you search by tags. You can also click on a tag within your channel list to see only the channels that match.

We also added support for tags within the ThingSpeak User API. Just pass the same tag into the API call to ThingSpeak, and you will receive a list of channels that match. This is really useful for integrating ThingSpeak into enterprise systems and for automating channel creation by deployed devices.

All of the tag-related features are available today to all ThingSpeak users!

Discussions About How to Use MATLAB and Arduino on the MATLAB Maker Community

As most of you know I love building IoT projects. Most of these maker projects use an Arduino, Particle, or Raspberry Pi, like my IR color-changing robot that connects to ThingSpeak and the CheerLights project.

I recently became the moderator of the MATLAB Maker Community that is hosted on MATLAB Central. There are many times where MATLAB and Simulink can help build a hardware-based project or be used to create the code running on a device. I also use MATLAB for analytics. Here are the most popular colors on CheerLights in the last 30 days.

The goal of the MATLAB Maker Community is to connect makers and builders together. I learn by working with others and sharing my work. If you are interested in maker project, I suggest following the Maker Community and jumping in on conversations or starting new discussions. I find this helpful if I am exploring a new idea or looking for feedback.

Right now, there is a discussion thread about how to use MATLAB to interface and interact with an Arduino. Makers can use MATLAB to control an Arduino by first installing the MATLAB® Support Package for Arduino®. Once you have the support package, you can use MATLAB to control the Arduino with familiar MATLAB commands.

% create an Arduino object
a = arduino('com3', 'uno');
% turn on an LED connected to Pin D11
writeDigitalPin(a, 'D11', 1);
% turn off an LED connected to Pin D11
writeDigitalPin(a, 'D11', 0);

Share your ideas on how to use the MATLAB connection to Arduino on the MATLAB Maker Community.