Connect a pot to your micro:bit as follows (Image source for diagram https://www.teachwithict.com/potentiometer.html). Note: The photo shows a pot which is designed to be mounted onto a Printed Circuit Board (PCB) so there are three pins rather than rounded lugs but you can't see this through the black tape. The alligator clips had less metal to attach to so the wires have been soldered on to make it easier to use in a classroom. The wires also happened to be different colours to those in the diagram.

Diving the output number by 102 creates a scale of 0 to 10. (1023 divided by 10 is actually 102.3 and you could use 102.3 if you want to be increase your accuracy.)

Diving by 102 will give you a decimal number most of the time. By adding the 'Round' function to your code you can convert the output number to an integer (i.e., whole number).

Resistance and current are inversely proportional which means that as the resistance decreases the current increases. Accordingly, full volume is achieved when the resistance is lowest.The following interactive simulation is based on Ohm's law which you learned about in SILO 5.4 'Electronics'. Try moving the sliders to see this for yourself.

Based on your new understanding of resistance and current, how can you modify your code so that the current is increased when the resistance is decreased?

In a mockumentary movie about rock music from the 1980s, the guitarist insisted that his amplifier is the loudest because it goes up to 11 rather than 10. Full volume (i.e., lowest resistance) could be called any number, such as 327, but it would not affect the volume. However, as a challenge, see if you can calibrate your code accordingly to go up to 11. Hint: There are two changes which you will need to make.

3. Stream over radio - Receiver

Rotating shaft challenge

Turning the shaft of an electric motor can convert mechanical energy into electrical energy. This is an example of the motor functioning as a generator. You would need a multimeter to measure the current that a small motor can produce, but you can measure the voltage with a micro:bit.

Using items which are readily available in the classroom, create a handle mechanism to help you turn the shaft of an electric motor. Use two wires to connect the terminals on an electric motor to pins 0 and GND on a micro:bit. The code for this is below.

Notes:

• The 'analog read pin' is found under 'Advanced' and then 'Pins'.
• The 'analog read pin' can be tricky as we found that it doesn't always replace the number in the 'Round' block. We found that it works best to combine the two math blocks and then add the 'Analog read pin' block. You might need to try reconnecting (i.e., connecting and then disconnecting) the blocks until they join correctly.
• The actual voltage should be somewhere around 50mV but the micro:bit displays the output on a scale between 0 and 1023. By dividing this number by 5 it becomes easier to read and compare.

Artificial Intelligence (AI)

A key component of both natural and artificial intelligence is the ability to learn. The photo below involves an animal that is learning to adapt to its environment.

Can anyone tell what is happening in the photo below?

This photo show a possum hanging upside down in regional New South Wales, Australia. The possum is demonstrating its intelligence by adapting to the recent installation of security lights. The small white object on the left of the possum is a moth which is attracted to the light. The possum hangs upside down to activate the light which then attracts unsuspecting moths which fly towards the silently waiting possum. Similarly, AI finds structure and regularities in events to acquire and develop skills. A big part of this is machine learning.

Machine learning using the micro:bit

Connecting a micro:bit to a moving person or object can open up some interesting possibilities using machine learning. You could use string and/or tape but there are also commercial options available such as the micro:bit wearable. The following image provides instructions for the micro:bit wearable. 

The following video (6:23) titled Getting started with micro:bit CreateAI shows some examples of how this can be achieved in the classroom. Step by step instructions are available at https://createai.microbit.org/.

Moderated self-assessment

Discussions with students around the key components of conceptual topics and how they fit together can generate insights into student achievement.