tappoz / tinkerforgetestproject

A minimum working example for the IoT using Tinkerforge technologies to show on an LCD screen the value coming from a light sensor

Tinkerforge building blocks for IoT (Internet of Things)

This project provides a minimum working example of a light sensor connected to an LCD screen to show a number representing the luminosity detected by the sensor.

The building blocks (or bricks and bricklets according to Tinkerforge terminology) are:

• Master brick http://www.tinkerforge.com/en/doc/Hardware/Bricks/Master_Brick.html
• Ambient Light bricklet http://www.tinkerforge.com/en/doc/Hardware/Bricklets/Ambient_Light.html
• LCD bricklet http://www.tinkerforge.com/en/doc/Hardware/Bricklets/LCD_20x4.html

The Master brick connects and controls the other bricklets (the light sensor and the LCD display).

Setup

Under Linux Debian/Ubuntu you need to install a couple of deb packages

• The Brick daemon http://download.tinkerforge.com/tools/brickd/linux/brickd-2.2.0_i386.deb
• The Brick viewer http://download.tinkerforge.com/tools/brickv/linux/brickv-2.2.1_all.deb

These packages have dependencies on libusb and some other python related packages, make sure to install those dependencies as requested by the dpkg command.

Tinkerforge components work on unique identifiers (cfr. the UID in the project code).

Another intersting brick is the RED brick, you need to plug it on top of the Master brick (cfr. http://www.tinkerforge.com/en/doc/Hardware/Bricks/RED_Brick.html). It contains a Cortex A8 processor with GPIO and a running Linux Operating System. If you decide to develop your application using the RED brick, then you need to compile your source code for that architecture. This is really easy when using the Brick viewer.

In the following image you can see the Master brick on the left, controlling the LCD bricklet and the Ambient light bricklet. The Master brick then is attached to the laptop via a USB cable.

Technologies

Tinkerforge provides a really flexible environment with a lot of supported programming languages.

I decided to go for Java 8 with Gradle to build the project.

On the command line:

$ # BUILD THE PROJECT
$ gradle clean fatJar
[...]
$ # RUN IT!
$ java -jar build/libs/TinkerForgeTestProject-fatJar-1.0.jar light
Illuminance: 60.6 Lux
Press key to exit

LCD Backlight turned off
Disconnected
$ 

Running the Java JAR then you can see the output on the command line. Please note that the illuminance information is displaied also on the LCD screen, after turning on the backlight, before turning it off.

Acknowledgment

A big thank you to Sven Ruppert who introduced these great toys during a Hack Lab organised by the London Java Community in January 2015.