micro:climate Kit Experiment Guide
Experiment 2: Reading the Light Level
Light conditions are a huge part of the weather. The great thing is that the weather:bit doesn’t have a light sensor. No, we didn’t miss a typo! The weather:bit doesn’t have a light sensor. Why not? Because the micro:bit has one already! In this experiment you will measure the light around you and have the micro:bit “graph” it
For this experiment you actually don’t need the weather:bit carrier board, so we left it out. But feel free to leave it attached to your micro:bit if you so choose.
- 1x micro:bit board (Not included)
- 1x micro-B USB cable (Not included)
- Using LEDs as Light Sensors — That’s correct! You can use LEDs as light sensors. In fact, that is how the micro:bit does it.
Again, the hardware hookup here is minimal! Plug your micro:bit into your computer with the USB cable, and you are good to go!
Running Your Script
Please open a browser window and navigate to makecode.microbit.org. This should open the MakeCode environment that you used to install the weather:bit package.
Code to Note
Set lightVal To
We read the light level in the area using the
light level block and store it in a variable called
lightVal. This is the value that we can compare against the calibration value you captured at the beginning of your script.
Plot Bar Graph Of
This block is fun! It accepts two values: the value of what you want to graph and a maximum value of that variable. In this case we want to graph
lightVal, and it has a maximum value of
255. This will create a “bar graph” of the light value on your micro:bit.
What You Should See
You should see the LED array light up as a graph based on how bright it is wherever you are. Turn out the lights or pass your hand over the array, and the graph should react. Pretty sweet! You now have a way to measure the light value as well as another way to display data with the micro:bit.
odd light readings — Make sure you are not leaning over the micro:bit, your shadow will impact the sensor reading.
The arrows threshold is odd — Try resetting the micro:bit while you are not leaning over it or casting a shadow on it.