1. Stem Discovery Week at Kareas High School in Greece
Vasiliki Servou
Activity1:
fruit keyboard and more with the micro:bit.
The BBC micro:bit is a simple affordable versatile programmable microcontroller with motion detection, compass, LED display & sensors, and Bluetooth, that can be coded, customized and controlled to bring your digital ideas, games and apps to life.
With 25 C class students (aged 15 years), we constructed an electric circuit with the micro: bit, using fruits and other conductors of electricity, to light up and change the brightness of LEDs and play notes on a buzzer or headphones.
From computer science, we studied the concepts of input, output, repetition, variables and event-oriented programming.
From physics, we studied the concepts of open and closed electric circuits, electric power source, electric current, earthing, electric conductors and insulators, and parallel and serial connection. We also studied ‘Ohm’s Law’. We connected a LED with a resistor. As the resistance increased, the LED became less bright and vice versa. In a similar way, we studied serial and parallel connection.
Each of the micro:bit elements is completely programmable via easy-to-use software on a dedicated website microbit.org, that can be accessed from a PC, tablet or mobile.
If you hold the ‘GND’ pin with one hand, you can program the BBC microbit to detect yourself touching the 0,1 or 2 pins with your other hand, giving you three more buttons to experiment with (you just used your body to complete an electrical circuit).

2. a model for a temperature alarm for egg hatcheries with the micro:bit.
Activity 2:
a model for a temperature alarm for egg hatcheries with the micro:bit.
112 students from A & B classes (aged 12-14) took part in another activity.
We used the temperature “sensor” of the micro:bit to sound an alarm and flash a light if the temperature was not appropriate for the eggs to hatch.
Concepts studied from physics included temperature measurement, open and closed electronic circuits, electric power, electric current and earthing, while from programming we studied selection structure, logical operators “and/or”, event-oriented programming and input and output.
More specifically using the Microsoft MakeCode block editor for the BBC micro:bit, we wrote a program that monitors the temperature. If it was less than 37o C or more than 38o C, it played the note C (4 beats long) on a loop as an alarm, and scrolled the temperature on the display.
Micro:bit thermometer
While it lacks a heat sensor, you can configure it to display the temperature of, say, a CPU, which is pretty handy for PC builders.
The BBC micro:bit does not have a dedicated temperature sensor. Instead, the temperature provided is actually the temperature of the silicon chip on the main cpu. As the processor runs cold though (it is a high efficiency ARM core), the temperature is a good approximation of the ambient temperature.
Otherwise, if the temperature was safe, it stopped playing the alarm and displayed a happy face. We set the temperature in the simulator (by dragging the arrow), to test our program. Then we connected a buzzer using crocodile clips, explained the open and closed electric circuit and earthing and we tried a colourful LED as another output.
This is the principle used by a thermostat to control the central heating in a home, or the climate control in many modern cars.

3. Feedback and Recommendations.
All my students were engaged in the activities, completed the tasks in time and understood the relevant material.
There was enough time for feedback.
In Greek High Schools (ages 12-15) the ICT lesson occupies 1 hour a week of the timetable. Activities using the micro:bit can be completed in an hour and students are inspired to think of further activities and relevant projects.
In addition, the ease of use of the micro:bit allows me to use it with all my students in class, not just the ones who are taking part in a competition or a project. Therefore, no student is left behind. .
Thank you for your time.