Sunlight Sensor
Sunlight Sensor & Extra Micro:bit Features
Activity Overview
Previously we鈥檝e used our micro:bit to record voltage data and store it on our computer to plot a characteristic curve. In this exercise we will begin testing some of the other functionalities of the micro:bit – in particular the in-built sunlight sensor. The LEDs on the front screen can emit light to form a pattern (as we鈥檝e seen before), but they can also harvest incoming light and convert it into an electrical signal.
You Will Need
- The Fully Electric Challenge Pack, specifically:
- BBC micro:bit GO Pack
- A computer/laptop with internet access
- MakeCode app (preferred) or MakeCode open in your browser
- Your kit car from yesterday
Get Coding: Basic Example
To start, we are going to create a simple example where we detect the light level on the micro:bit鈥檚 LED screen and display two different patterns depending on how much light is detected.
Step 1: Create a new MakeCode project, delete the on start block and input an if/else block from the 鈥淟ogic鈥� module:
Step 2: Within the 鈥淟ogic鈥� module, drag a 鈥�0 = 0鈥� block from the comparison section and drag it into the hexagonal 鈥渢rue鈥� box:
Step 3: Drag the round 鈥渓ight level鈥� block from the 鈥淚nput鈥� module to the left hand side 0. Then type in 100 into the right hand side 0 and change the operator from equals 鈥�=鈥� to more than 鈥�>鈥�:
Step 4: Drag two 鈥渟how leds鈥� blocks from the 鈥淏asic鈥� module, one to be placed under the if statement and the other under the else statement. You can customise which LEDs light up however you want, I have chosen a sunny looking pattern for light levels above 100 and a moon pattern for when it drops below 100:
Our basic example is complete! If you press download as before with the micro:bit connected via USB to your computer, your program will be saved onto your micro:bit. If you are in a bright room and your micro:bit is showing a sunny pattern to begin with, try covering the LEDs and you should see the pattern change over. Alternatively, if you are in a darker room you can use your phone torch to illuminate the screen. It鈥檚 now time to add some extra features to our program!
Upgrading Our Program
By implementing a few extra blocks, we can upgrade our program to display animated patterns! Since the micro:bit has an on-board speaker, we can also play single notes or custom tunes depending on the incident light level.
Animating our screen
By including 鈥減ause (ms)鈥� blocks from the 鈥淏asic鈥� module and adding extra 鈥渟how leds鈥� blocks we can very simply create an animated gif for each of the two scenarios:
Note: Feel free to add as many layers to the animation as you want!
Adding sound
After poking around in the 鈥淢usic鈥� module you will see you have the option to play a musical note, a custom melody and even change the tempo/volume of your sounds:
Final step: Once you are happy with your program and you have tested it works correctly – you may unplug your micro:bit from your computer and attach it to your kit car with the battery box provided. You have now created a mobile sunlight sensor which can annoy everyone in your household!
Bonus Tutorials
If you are interested in further examples of what your micro:bit has to offer, feel free to visit the link below in your spare time and browse an extensive list of tutorials. Some extra features of the micro:bit that weren鈥檛 covered today include a microphone, temperature sensor, compass, accelerometer, and many others!
Here is a sneak peek at some of the projects you will encounter on the website鈥�
