This article is contributed. See the original author and article here.

Today is a look back at a guest blog post from a teacher, Jez Dean

Originally written on 09/13/2017.




In this blog post: Build a computer-to-micro:bit connection with Small Basic.


You can write a simple GUI to send commands to a micro:bit running Python:




The program sends Python commands over a serial connection to the micro:bit. I’ve kept it as simple as possible so you can customize it further.

Clicking PIN0 High sends the command pin0.write_digital(1) to the micro:bit. You could type and click Send Command would show a smiley on the micro:bit.



  1. Flash a Python program to the micro:bit. You can just flash an empty program from within mu.

  2. Install the lit dev extensions for Small Basic. These are used to communicate over a serial connection.

  3. Find out the COM port of your micro:bit.

  4. Add your COM port at the top of the Small Basic code.


 comPort = “COM4”


While (“True”)

Sub Initialise
‘draw window’
GraphicsWindow.Width = 500
GraphicsWindow.Height = 100
GraphicsWindow.Title = “Small Basic Microbit Controller”

‘draw pin control buttons’
pin0high = Controls.AddButton(“PIN0 High”, 20, 10)
pin0low = Controls.AddButton(“PIN0 Low”, 100, 10)

‘draw status and command buttons & boxes’
statusbox = Controls.AddTextBox(20,50)
value = Controls.AddTextBox(210,13)
send = Controls.AddButton(“Send Command”, 380, 10)

‘Open connection to microbit’
Controls.SetTextBoxText(statusbox,”Status : “+ LDCommPort.OpenPort(comPort, 9600))

‘Assign variables’
Controls.ButtonClicked = OnButtonClicked
nl = Text.GetCharacter(10) ‘new line character’

Sub OnButtonClicked
button = Controls.LastClickedButton
val = Controls.GetTextBoxText(value)

‘if button pressed, send command and new line character’
If (button = pin0high) Then
ElseIf (button = pin0low) Then
If (button = send) And (val <> “”) Then

Adapted from litdev on the Small Basic blog.



  • This is not interactive; it will not return any value the microbit sends.

  • This will only work over USB. Python does not work over Bluetooth.

See Also

Other Resources from Jez Dean (website is down now)

Brought to you by Dr. Ware, Microsoft Office 365 Silver Partner, Charleston SC.

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