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Lesson 38 MicroPython: Reaction Time Tester

  • Create a reaction time tester using the micro:bit and an OLED display. This tutorial was written by Jensen from Raffles Institution.

Objectives​

    1. Assemble a reaction time tester
    1. Try not to break it while testing your reaction speed!

Materials​

  • 1 x Tinker Kit (or an OLED display)

Step 1 - Input / Output​

  • Connect the Micro:bit to the breakout board.
  • Connect the LED to pin 12, which is a digital pin.
  • Connect the light detector to another digital pin, pin 8.
  • Brown wire to G (Ground), red wire to V (Voltage), orange wire to S (Signal).
  • These components detect whether the light is on or off.
  • Connect the OLED display to the I2C pins. Any I2C port will work.
  • Connect the micro:bit to your computer and download the Mu Editor.

Step 2 - File Transfer​

  • We need to download some modules to use in the project.
  • Download the modules as a zip file from this link.
  • Write the code (first screenshot) in the Mu Editor to import the files.
  • Make sure the files are in the same folder as the project.
  • Transfer some files from your computer to the micro:bit.
  • On Windows, be sure to place the files in the folder under users/"Username"/mu-code so that the Mu Editor can detect them.
  • These are modules that are not pre-installed on the micro:bit for you to import.

Step 3 - Loading Screen​

  • This step is not required, but it adds a nice touch to your project.
  • We display this loading screen on the OLED module.
  • Using the "add_text" module, we can display text and other characters on the screen.
  • We use the "loading_screen()" function to display the animation.
  • Head to the bottom of the post if you want more variations of the loading screen.

Step 4 - Code the Game​

  • This is the actual test itself.
  • First, we need a time delay before showing the indicator for the player to press the button.
  • We generate a random number and parse it into milliseconds by adding "000" to the end of the original number after converting it to a string.
  • The variables time1 and time2 refer to 2 arbitrary time points before the "#" (player indicator) symbol is displayed.
  • An important point to note about MicroPython and the Micro:bit is that the time module is replaced by the utime module, and you must import utime instead of time.

Step 5 - More Logical Programming​

  • This is the step where we calculate and display the player's reaction time.
  • This is done by calculating the time between the indicator appearing and the player pressing the button.
  • We then display the player's reaction time on the OLED screen.

Extra Loading Effects:​

  • This uses the light sensor and LED to start the game.
  • It detects light, and once the light is covered, the game starts.
  • The next animation is simple: display the characters "3", "2", and "1" as a countdown before starting the game. The code is very self-explanatory.