Micro:bit Line-Following Robot

I was looking for an extension to the Micro:bit Go set that I bought a while back and came across a robot set that is currently on sale. This set comes with most of the sensors a typical line following or obstacle avoiding robot needs. Currently, it is being sold at a fraction of the price of other similar Micro:bit robots, and is far cheaper than sets such as the Lego EV3.

After unpacking it earlier this evening after work, I managed to put together the parts by following the instructions, which were quite clear.

1. Micro:bit Go (S$30 on Lazada) 2. Yahboom Micro:bit Robot (selling for S$49.68 only at Lazada)

To program the robot using Micro:bit's Makecode, which is a block programming interface that is very similar to Scratch, you will need to download the Yahboom blocks by selecting Extensions from the Advanced menu.

Enter the following URL into the search bar: https://github.com/lzty634158/yahboom_mbit_en

You will then see the library of new blocks including those meant for the robot below:

A few simple lines of code are all that is needed for the light sensors to keep tracking a black line by turning whenever one of the sensors detect white while the other detects black.

After programming the robot, download the hex file into the Microbit and the robot is good to go.

Javascript Game to Learn How to Count Money

Trying to brush up my Javascript skills after being inspired by one of the senior specialists in ETD, I created this simple Javascript Game to teach kids how to count money using Singapore coins.

To play this game, click or press the "Play Button". Click on the coins to make up the targeted amount. Be careful as the coins will move over one another.

This is meant for children entering primary one soon so that they can learn how to pay for food at the canteen.

GeoGebra in SLS

1. update on 2 Jul 2019: The SLS lesson shared during IPSG 2019 can now be found in the SLS Community Gallery.
2. Join the local community of GeoGebra users at: https://www.geogebra.org/group/stream/id/VFX2EG8xa
3. GeoGebra tutorials at: https://www.geogebra.org/m/Ebm5wBW5  (Start with Geometry and Functions & Graphing)
4. GeoGebra apps curated for A-level Physics: https://www.geogebra.org/m/dgedzmz3
5. GeoGebra apps curated for O-level Physics: https://www.geogebra.org/m/z5nfs8qd
6. IPSG Poster on "An SLS Learning Experience with GeoGebra Apps on the First Law of Thermodynamics"
7. Instructions on how to embed GeoGebra into SLS.
8. Let us know if you have used or adapted the SLS lesson, or if you have ideas for new GeoGebra apps in the comment section below.

Geogebra Simulation of a Potentiometer

Some of the more challenging problems in the topic of electricity in the A-level syllabus are those involving a potentiometer. The solution involves the concept of potential divider and the setup can be used to measure emf or potential difference across a variety of circuits components. Basically, students need to understand the rule - that the potential difference across a device is simply a fraction of the circuit's emf, and that fraction is equal to the resistance of the device over the total resistance of the circuit.

$V_{device}=\frac{R_{device}}{R_{total}}*emf$

The intention of this Geogebra app is for students to practise working on their calculations, as well as to reinforce their understanding of the principle by which the potentiometer works.

Geogebra Apps for Singapore Physics

I've curated a series of Geogebra apps that are relevant and useful for the instructional objectives under the Singapore-Cambridge GCE 'O' and 'A' level syllabi. Some of these apps were created by myself. If you have any ideas for new Geogebra apps, do let me know in the comments section below and I'll see if it's possible to create. Alternatively, if you have come across other Geogebra apps that can be relevant to the local physics syllabus, I would gladly include them into my lists!

 O level Physics Geogebra Apps A level Physics Geogebra Apps

Box on a Vertical Oscillating Spring - Geogebra App

Students can explore how varying frequency and amplitude of the vertical oscillation of a platform could cause an object resting on it to temporarily leave the platform (i.e. when normal contact force is zero).

Geogebra App for Kinematics

As one of the first topics in A-level physics, kinematics introduces JC students to the variation of velocity and displacement with acceleration. Very often, they struggle with the graphical representations of the 3 variables.

This Geogebra app allows students to vary acceleration (keeping it to a linear function for simplicity) while observing changes to velocity and displacement. Students can also change the initial conditions of velocity and displacement.

The default setting shows an object being thrown upwards with downward gravitational acceleration of 10 m s-2.

The movement of the particle with time is shown on the left with a reference line showing the position on the displacement graph.

Wavefront

In order to help students visualise a wavefront, a 3-D image is usually used to show the imaginary line joining particles in phase. I created the Geogebra apps below to allow students to change the wavefront and observe it move with time at a constant wave speed. There represent simplified versions of waves on a ripple tank with a linear and circular wavefront.