Case 03：Thermometer

Our Goal

Use watch kit to create a wearable thermometer.

Material

1 x Watch kit

Hardware Connection

Assemble our watch kit directly just like the picture below.

Software

Microsoft Makecode

Programming

Step 1

Create a variable flag. Initialize this variable to 0 when we startup our micro:bit. When button A is pressed, set the flag to 1.

Step 2

Create a forever loop and insert show icon block with a heart under it. If the flag equals 1, then assign the temperature value to the variable Tem.
If the variable Tem is beyond 30 degrees, display a crying face and show string "So Hot"。And then delay 0.5 second after displaying the temperature.

Step 3

If the variable Tem is under 20 degrees, display a crying face and show string "So cold". And then delay 0.5 second after displaying the temperature.
If the temperature is among 20 degrees to 30 degrees, then display a smile face and delay for 0.5 second after showing the temperature.
Set flagto 0 to exit the function above.

Program

The link of whole program: https://makecode.microbit.org/_iHY0ReVrTJJX
You can also download the program from the page below.

Result

We can see a smile face and temperature on micro:bit screen.

Think

Q: Sometimes the temperature is obviously under 20 degrees, why the displayed number is much higher? A: Because the temperature obtained by micro:bit is the temperature of main chip, instead of environment temperature. When micro:bit runs for a long time, the chip will be heated significantly.