Logo Interreg Slovakia-Austria European Regional Development Fund Faculty of Electrical Engineering and Information Technology, Slovak University of Technology Logo Robotika.SK Logo Faculty of Mathematics, Physics and Informatics, Comenius University    Centrum vedecko-technických informácií SR

Deadline of this assignment is set to: 2016-05-03 20:00:00

1. Task: Creative meteorology and minute hand

1. April is the month with the most variable weather in Slovakia. So it is a suitable time for experiments with measuring and recording the weather! The creators of LEGO MINDSTORMS Education told us about the EV3 that "it is a solution not a product" and also that "it is a true datalogger" :-). Well, true, it can handle a 32GB memory card! This allows one to leave the brick connected to the wall outlet through a power adapter even for a month and keep recording a lot of data meanwhile. In our case, we will be recording data, but the amount will not be so large. A usual NXT brick will be sufficient too.

meteorological station at Lomnický štít

Task: Build various components for a meteorological station (at least one), which will measure various data about the weather, for instance speed and direction of the wind, degree of the brightness of the sky, atmospheric pressure, temperature, precipitation, etc. The 5th task in Summer League is usually a creative one, therefore we leave the details to your creativity! Our requirement is that only the standard NXT or EV3 sensors will be used. This rules out temperature sensor, compass sensor, accelerometer, gyroscope, and similar. The components that you build do not have to be operational with one control unit (NXT/EV3) all at the same time. You can test each one separately. You do not need to run the station outdoors. However, you can do that, if you want to. In that case, make sure to insulate the electric parts well from any moisture. A demo in interior will make us happy enough and it will be sufficient for this task. You can simulate the weather phenomena in some creative way. The station should record the measured data into a file. Upload the recorded file over to a PC and visualize the data in a chart. Explain how you did it. Please remember to include a picture of your team, picture of the robot, program, measured data, add a description and a link to an unlisted YouTube video as always.

2. The construction set contains several sizes of gear wheels. In the classical set, there are 8, 16, 24, and 40 teeth gears.

basic set of gear wheels

The new set of gear wheels consists of 12, 20 and 36 teeth gears. They are useful, because they can connect even if the axles come in a perpendicular direction.

a new set of gear wheels

Interconnecting the gear wheels into complex gears, we can get various ratios between rotational speeds of the gear attached to and propelled by the motor and the output gear connected to a car wheel, for instance.

an example of a double gear 3:1

One can possibly build many different gears with different input-output gear ratios. Can you list them? At least simple gears and double gears? Perhaps tripple gears?

The move block in the EV3 or NXT software allows to specify the required "power" of the motor - in reality this parameter specifies the required rotational speed. What is the ratio between the specified power and the resulting rotational speed? Is it possible to describe it using a math formula?

Build a clock machine for a minute hand. The hand should make a single rotation exactly in 1 minute. Select a proper gear ratio and set the proper "power" in the move block. Design your solution in theory first - compute it using the measurement you performed earlier, as required in the text above. Then build the designed solution and verify it by a measurement. If it will be needed, improve it. Document your progress and the outcome.

If the tasks seem too difficult, you can make them easier to fit your level and time possibilities.

We look forward to your solutions!

Solutions