In this workshop students get an insight into using micro-controllers in combination with sensors. The best known system for educational purposes is the Arduino family of micro-controllers, the most popular being the model UNO (see https://www.arduino.cc/ for more information. The original UNOs are available at about 20 Euro, cheaper copies can be bought for about 7 Euro).
Measuring temperature and humidity are among the things that can be done most easily - and most cost effeciently. Of course these data can easily be gained by using conventional intruments and writing down the data by hand. The great advantage of a micro-controller based system lies in the fact, that it can take down the data at freely definable intervalls and for a long period of time. This way students could for example track the development of the temperature of their classroom with an automated system. These data can be written on an SD-card and later be evaluated with the help of a spreadsheet software (Microsoft Excel or LibreOffice Calc). However due to a lack of time, this is not part of this workshop - though it would be sensible.
In this workshop students
- get to know the IDE and the micro-controller,
- use LEDs for the first steps,
- connect and use the temperature sensor,
- write the data to an SD-card and
- use a real-time clock to add the date and time to the measurements.
In theory this setup can be extended with a lot of different sensors. There will be an even shorter workshop at the meeting in Adria. This will not deal with recording any of the data but with just measuring the temperature of water with another sensor. For example you could detect particulates, CO2 or other gases with dedicated sensors or use color sensors to evaluate various tests, e.g. a litmus test for pH values.
The materials for the project described here cost about 400 Euro for 9 sets - that's of course without the computers needed to program the controllers. Each set comprised:
- an Arduino UNO
- a breadboard
- 2 LEDs and 2 resistors (220 Ohm)
- a DHT22 temperature sensor and a resistor (10k Ohm)
- a real-time clock module
- an SD-card shield
- a micro-SD card
- a power bank or battery pack
- various cables
Materials can be bought much cheaper at Chinese websites if you allow a lot of time for delivery. The parts can be used for different projects or projects can be extended in many ways.