Logging the Data – basics

Now that students have their micro:bit logging device we need to set them a task to investigate. But, before that, students need to understand the measurements they are collecting.

When using the light sensor the micro:bit simulator changes to show the default light measurement which is 128 and a yellow half circle. Click on the circle and drag up , the amount that is coloured yellow will change. Drag until there is no yellow left. The display show 0. This represents no light. Drag downwards and fill the circle with full yellow. The display will show 255, Full light.

So now we have a minimum value , 0, a maximum value 255 and a mid point value 128. You may want to ask students what is the mid point of 255? 255 divided by 2 equals 127.5. So why is the micro:bit showing 128 as the mid point? It is because in computing , 0 is a value, a number. The micro:bit is showing 0-255, that means it is dealing with 256 values, mid point of which is 128.

The temperature sensor works in a much more straight forward way. Again the simulator will show a virtual thermometer. Which can also be changed by dragging up and down. It will show the maximum value of 50C and a minimum -5C.

You may want to ask students if they think the temperature reading is an accurate measurement and how could they check this? The micro:bit will generate its own small amount of heat. This will affect the accuracy of the readings. Students could check how much of an affect, by using a thermometer next to the micro:bit and they could compare the difference. They could then subtract this from the micro:bit reading in their recordings.

Now students have a simple device to record light or temperature. They can undertake different science investigations. Such as the warmest or coldest places around the school, or are different colour surfaces different temperatures or my favourite,, which is the best place for the Headteacher to their book, where the light is not too bright or too dark

This post shows how to take simple measurements with the micro:bit and is a great way to using computing in science lessons. The next post will develop this, students can use code to improve the accuracy, as in the case of the thermometer and the functionality of their micro:bit measuring device.