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Simuated sensor values

Narrow Band IoT Board with SIM Nano card

Front End Dash Board

Local reading & App "realtime" value

Reading of remote sensors from a Mobile App

Using a Narrow Band IoT Gateway and programming it using the Legato Framework, I pushed simulated sensor readings to the cloud, displayed them on a Web Frontend and also on a mobile App with almost real time.

Prototype with own power system and sim card for demostration purposes.

Final prototype for demostration purposes and the linked mobile real time App


Values are read from a C program runing on a Linux module programmed with the Legato Application Framework, an open source and secure Application Framework to grow the "Internet of Everything". Part of the project code can be found in this GitHub repository

The project consists of a IoT devices with input/output sensors, a Linux Module with Open Source Firmware, an embeded program developed for the purpose of this project, the Google Cloud, Firebase and a Mobile Application build with the Android SDK. The Web Frontend was developed using the Google Web Toolkit runing on the Google Cloud App Engine.

Youtube Video explanations

This video explains the purpose of the prototype and each of the components of it, from the sensor simulation using varistors, to the measurements being done using two multimeters (non calibrated but good enough for the purpose of this demo), how this values are being read using the analog inputs of the IoT board, being sampled and converted to digital using the build in ADC Analog to Digital converters and pushed to the Cloud using the MQTT prototcol, with data being encrypted.

IoT module, simulated sensors, multimeter, backend logs and realt time readings from a mobile phone

Varistors to simulate light and temperature sensor that are input to the ADC converter of the IoT module

The Legato Application Framework

The Legato Application Framework is designed to provide a smooth and connected open source platform that allows developers to easily work with the various wireless technologies and enable new ideas on IoT devices.

Image property of Legato

Web FrontEnd

On the video we can see how values are displayed on a Web Front End. We can also see how this values are loged in the Google Cloud Platform.

Google Cloud's operations (formerly Stackdriver)

The video shows the values beeing stored on the Google Cloud Platform and their readings tracked in the logs using Google Cloud Operations suite (previously known as Stackdriver).

Android App with Real-time values

The App is programed in Kotlin and uses an API to read the backend database with value stored from the IoT Gateway.

Screenshoot of the App reading values in almost realtime. The mobile phone time on the upper right hand side shows 9:38h whereas the App shows 8:38:38h. This is because the backend is in a different time zone than the App and it serves to prove, that the data is displayed in almost real time, at the hour and 38 minutes.

Marc Farssac
Interim Android
Developer & Team Leader

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Marc Farssac

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