oneM2M Potentiometer/PushButton/LCD with NodeMCU (ESP8266)

1.High level architecture

2.Prerequisites

The following tools are required to run this demonstration.

• A runtime environment for the chosen oneM2M platform (cf. section 3) :
  - Java Runtime Environment (JRE >= 1.8) if you use Eclipse OM2M
  - Python 3 environment if you use ACME
  - NodeJS environment if you use KETI Mobius
• Arduino IDE 1.8.9 (or later)
• Your favorite IDE to develop your IoT application
• Node.js environment OR Python environment for IoT Applications
• Postman (Optional)

3. Download the project

Download the necessary resources from the main repository:

https://github.com/oneM2M-Tutorials

This repository includes different projects:

• oneM2M-IoT-Device: The NodeMCU Sketch(es)
• oneM2M-IoT-Application: IoT applications written in Node.js & Python
• oneM2M-IoT-Device-Simulator: Node.js program to simulate various IoT sensors & actuators

You will also need an implementation of oneM2M platform. Different platforms exist, we can cite some:

• Eclipse OM2M: An open-source implementation in Java (link)
• ACME: An open-source implementation in Python (link)
• KETI Mobius: An open-source implementation in Node.js (link)

For this tutorial, ACME implementation will be used. Refer to the official documentation for installing, configuring, and running the platform.

https://github.com/ankraft/ACME-oneM2M-CSE

4. Start the oneM2M-compliant IoT Platform

4.1. Configure the IoTPlatform (ACME)

The default configuration can be used for a local demonstration. The IoT platform will listen on port 8080. The database is reset after each restart.

If needed, you can change the configuration of the IoT Platform by editing the file: "acme.ini”.

4.2. Start the IoTPlatform (ACME)

The IoT Platform can be launched through:

python3 acme.py

You should see at the end of the logs "CSE Started".

4.3. Login to ACME web interface

Open the following URL in your browser to access the ACME IoT platform web interface: http://127.0.0.1:8080/

With the default configuration, enter the originator "CAdmin" and then "Connect"

You will be then able to see the oneM2M resource tree:

5. Connect your IoT Device

The NodeMCU source code is available on the folder "oneM2M-IoT-Device" folder.

5.1. Schematics

Connect the Potentiometer, the 4-Digits Display, the Push Button, the LCD Display to the NodeMCU board using the following components:

• Breadboard
• NodeMCU board
• Potentiometer
• Push Button
• 4-Digits 7-Segments Display (TM1637)
• LCD Display (2x16)

5.2. Set up Arduino IDE for NodeMCU development

If not already installed, download and install the Arduino IDE from the following link: https://www.arduino.cc/en/Main/Sousing

NB: We do not recommend using the Arduino Web Editor for this demonstration because the NodeMCU board is not supported.

When plugged, if the NodeMCU port is not detected, then you need to download and install the USB driver manually using the following link: https://github.com/nodemcu/nodemcu-devkit/tree/master/Drivers

5.3. Add NodeMCU board support to Arduino IDE

Firstly, open the Arduino IDE, go to "Files" > "Preferences" entry.

Copy the below URL in the "Additional boards Manager URLS" Textbox:

http://arduino.esp8266.com/stable/package_esp8266com_index.json

Click "OK" to close the "Preferences" dialog box.

After completing the above steps, go to "Tools" > "Board:..." and then select "Board Manager"

Type in the textbox "esp8266", then navigate to "esp8266 by esp8266 community" and "install" the software for Arduino.

Go to "Tools" > "Board...", and then select "NodeMCU 1.0" board.

Once all the above process been completed, you are ready to program the NodeMCU board with Arduino IDE.

5.5. Configure the NodeMCU sketch

Open the sketch "NodeMCU_PotentiometerSensor-DisplayActuator.ino" in your Arduino IDE.

Set your WIFI parameters

• char* WIFI_SSID = "FILL_THE_WIFI_SSID";
• char* WIFI_PSWD = "FILL_THE_WIFI_PSWD";

Set the IP address of the ACME IoT platform in your network:

• String CSE_IP = "X.X.X.X";

5.6. Compile the NodeMCU sketch

Click on verify button to compile the sketch.

Compilation output:

5.7. Upload the sketch to the NodeMU board

Click on upload button to upload the sketch to the NodeMCU board.

Upload output:

5.8. Debug the code execution using serial monitor

Click on button to open the Arduino Serial Monitor to display the NodeMCU console.

Then after opening the Serial Monitor select 115200 from the drop-down list.

5.9. Check IoT device resources on ACME web interface

You should see “PotentiometerSensor” Application Entity resource with “DESCRIPTOR” and “DATA” containers created on the oneM2M web interface.

You should also see “DisplayActuator” Application Entity resource with “DESCRIPTOR”, “DATA”, and "COMMAND" containers created on the oneM2M web interface.

6. Connect your IoT application

The potentiometer monitoring and display management application source code is provided in NodeJS and Python. The source code is available on the folder:

• "oneM2M-IoT-Application/nodejs/onem2m-monitor.js"
• "oneM2M-IoT-Application/python/onem2m-monitor.py"

6.1. Configure the application

You can use one of the two provided applications: NodeJS OR Python

6.1. Option A = NodeJS IoT Application

Open the file nodejs/config/default.json with your favorite text editor. and edit the necessary configuration parameters.

Set the IP address of the ACME platform (variable "monitorIP"). You can keep localhost (127.0.0.1) if you are running the ACME platform and the application in the same computer.

6.1. Option B = Python IoT Application

Open the file python/default.json with your favorite text editor. and edit the necessary configuration parameters.

Set the IP address of the oneM2M platform (variable "monitorIP"). You can keep localhost (127.0.0.1) if you are running the oneM2M platform and the application in the same machine.

6.2. Start the application

6.2. Option A = NodeJS IoT Application

On a terminal, install the following Node.js modules using the npm tool (installed by default when Node.js is installed):

> npm install express
> npm install request
> npm install body-parser
> npm install request
> npm install yargs
> npm install config

Start the Node.js oneM2M IoT application using the following command:

> node onem2m-monitor.js -s Potentiometer -a Display

6.2. Option B = Python IoT Application

On a terminal, install the following Python modules using the pip tool (can be installed when Python is installed):

> pip install requests
> pip install flask

Start the Python oneM2M IoT application using the following command:

> python onem2m-monitor.py -s Potentiometer -a Display

6.3. Check IoT application resource on ACME web interface

You should see “Monitor” Application Entity (AE) resource created on the oneM2M web interface. Also check the creation of Subscription resource under PotentiometerSensor/DATA

7. Demonstration

When you change the position of the potentiometer, its value is directly copied on the 4-Digits Display.

When you push the button, the value of the potentiometer is sent over WiFi to the remote CSE. This value is then notified to the monitor application.

Based on the received value, the monitor application will send a specific message to the LCD Screen through the CSE.

if the value is lowerthan 512 (respectively higher than 512), the monitor application will send "Value is LOW" (respectively "Value is HIGH") to be displayed on the LCD Screen.

8. Going further

If you have a second NodeMCU, you can split the sensors and actuators over the two NodeMCU devices.

8.1 Architecture

8.2 Schematics

8.3 NodeMCU Sketchs

You can find the original sketch code splitted into two new sketchs in the folder:

"oneM2M-IoT-Device/PotentiometerSensor_DisplayActuator"

NodeMCU 1 (sensor only)

• "PotentiometerSensor/PotentiometerSensor.ino"

NodeMCU 2 (actuator only)

• "DisplayActuator/DisplayActuator.ino"

8.4 IoTApplication

Thanks to oneM2M standard, you can use the same IoT application without any changes :-)