In this example we will create a VB.net program that will read data from the serial port, in this case a Microbit connected to the PC. We will then upload a program to our microbit that sends data via the serial port when a button is pressed.
This is a picture of the app will be creating, as you can see it has a combo box with available comms ports listed, connect and disconnect buttons and a textbox which will display serial data from the microbit. You can see the app running and the results of some key presses
This was written in python using the Mu editor
from microbit import * while True: if button_a.is_pressed(): print("Button A was pressed") sleep(250) elif button_b.is_pressed(): print("Button B was pressed") sleep(250) sleep(100)
Imports System.IO.Ports Public Class frmMicroBit Dim WithEvents serialPort As New SerialPort Delegate Sub myMethodDelegate(ByVal [text] As String) Dim myDelegate As New myMethodDelegate(AddressOf DisplaySerialText) Private Sub GetSerialPortNames() For Each sport As String In My.Computer.Ports.SerialPortNames cboPorts.Items.Add(sport) Next End Sub Private Sub frmMicroBit_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Try GetSerialPortNames() cboPorts.SelectedIndex = 0 Catch MsgBox("No ports connected.") End Try End Sub Private Sub btnConnect_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConnect.Click Try serialPort.BaudRate = 115200 serialPort.PortName = cboPorts.SelectedItem.ToString serialPort.Parity = Parity.None serialPort.DataBits = 8 serialPort.StopBits = 1 serialPort.Open() If serialPort.IsOpen Then btnConnect.Visible = False cboPorts.Enabled = False btnDisconnect.Visible = True End If Catch serialPort.Close() End Try End Sub Private Sub btnDisconnect_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDisconnect.Click Try serialPort.Close() btnConnect.Visible = True btnDisconnect.Visible = False cboPorts.Enabled = True Exit Sub Catch MessageBox.Show("Problem closing port") End Try End Sub Sub DisplaySerialText(ByVal myString As String) txtSerial.AppendText(myString) End Sub Private Sub SerialPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles serialPort.DataReceived Dim str As String = serialPort.ReadExisting() Invoke(myDelegate, str) End Sub End Class
I uploaded the example VB.net app to https://drive.google.com/file/d/0B7mkEkhIEzkNMVVMZEZHbW8wUzA/view?usp=sharing