PJ008: Light Triggered Alarm Clock with Micro:bit

Hardware setup

Basically, we only need the Micro:bit single board, with the USB cable, nothing more.

Programming

• We shed a table light toward the Micro:bit board, which is fully covered by hands (or other helper materials) to simulate a very dark environment

  • Micro:bit should be quiet, nothing special happens

• We open the covering slowly, to simulate the day getting brighter and brighter, when it reaches a "brightness" level that you define as right time to get up from the bed

  • Micro:bit plays an alarm sound for 1 time, after this, it keeps quiet even the environmental light gets brighter till we fully open the hands

• Then, we slowly cover back, to simulate the day becoming darker and darker, until we fully cover the Micro:bit board again

  • During this darkening-process, the Micro:bit board should always keep quiet, nothing should happen

• Then again, we gradually open the hands, until it gets bright enough, then the Micro:bit sounds the alarm again for another new day!

• We should be able to repeat the above day-brighting and day-darking process with the reliable result

[x] Simple: 30-60 minutes

[ ] Moderate: 1-2 hours

[ ] Challenging: more than 2 hours

The estimation bases on average situation without unexpected troubleshooting, assuming that the student meets prerequisites. It only indicates rough time needed to complete this project, but not about technical difficulty, not covering discussion and sharing time. Here is a possible breakdown:

• 5 minutes: Understand requirement and solution, collect materials 

• 10-15 minutes: Programming prototype, test and find out improvement points

• 15-20 minutes: Programming refinement, refactor and retest

Usually, by this tip so far and active exploration, you can get it done! Please try really hard, before getting super tips if you are stuck.

Stand in front of the class, share with your group what you have made, please cover important points

• Tell what it is your product

• Demonstrate how it works

• Explain how it works

Share with your group about

• What troubles you met

• How you analyze

• How you get help

• How you solve it

• What you have learnt

Use your own way to visualize how the hardware components are connected by a free style drawing.

• Visualize clearly the wiring path, mark clearly the pins and end points

• So that your friends can follow this drawing to correctly reproduce the hardware setup 

Any kind of children style drawing is OK! Here are some examples.

Use your own way to visualize how the programming controlling logic is done, by a free style drawing, so that your friends can follow this flow-chart to reproduce the programming.

You might be interested to know what is "flow chart", click to learn more, but so far, it's not needed to be that serious, just draw something that can help you explain to your friends how the programming is made.

1. Tell us what is variable and what is boolean type variable in your own way, explain how this variable helps you in this project.

2. What if you forget "on start" setting to initialize the variable?

3. What if you forget to update the "is_led_on" Boolean variable (flip to its opposite side) after turning on/off the LED?