Simple Serial Monitor

Simple Serial Monitor is yet another stand alone replacement for the Arduino serial monitor. It is text only and is far from being a fully fledged terminal app. It does have a couple of features that make it a little better than the regular Arduino serial monitor, especially when used with UART modules like the Bluetooth modules I often play with.

Simple Serial Monitor was created as an example of using the serial port in Visual Basic NET. The app is written in Visual Basic.NET (Framework) and uses .NET 4.8. NET 4.8 is an older version of .NET that has drag & drop serial ports in the designer making serial ports a little easier to implement.

The compiled app does not need installing and can be run by double clicking the file. You can download the app and the source files below.

Simple Serial Monitor talking to a Bolutek BC04 Bluetooth module

Controls

Enable/disable automatic scrolling in the main window.

Make the main window text smaller
Make the main window text larger

The mini scale in the middle indicates the current text size

Enable and disable showing system messages in the main window. System messages are displayed in red.
Show things like, when a connection has been made or broken, error messages.

When checked, sent text is copied to the main widow. Sent text is displayed in blue.

Contains a list of common baud rates.
300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 74880, 115200, 230400, 250000, 500000, 1000000, 2000000

List containing line end characters,
– Both NL & CR
– No line Ending
– Carriage return (CR)
– New Line (NL)

COM port list and connect/disconnect button.
The COM port drop down lists contains the available COM ports. This list is automatically updated when there isn’t an active connection.

Serial port settings button. Click to open the settings panel:

The serial port settings panel has settings for
– Data Bits
– Parity
– Stop Bits
– Character encoding

Arduino serial default to Data Bits: 8, Parity: None, Stop Bits: 1. This is also known as 8N1.

Data Bits
– 5 Bits
– 6 Bits
– 7 Bits
– 8 bits

Parity
– None
– Odd
– Even

Stop Bits
– 1 bit
– 2 bits

Character Encoding (Encoding)
– Default (The system default)
– UTF8
– Unicode
– ASCII
– UTF7
– UTF32

Use Simple Serial Monitor With An Arduino

Simple example just to show things working. An Arduino connected to a computer via a usb cable.

Sketch

Simple sketch to demonstrate using serial in to turn an LED on and off.
A ‘1’ turns the built in LED on, and a ‘0’ turns it off.

/*
 *  sketch: Serial_simple_serial_test
 *  www.martyncurrey.com
 *  
 *  Turn the built in LED on and off using simple serial commands.
 *  1 for on
 *  0 for off
 *  
 */

const int LED_PIN = 13;
char c=' ';

void setup() 
{
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);

  // 8N1 is the default setting for the Arduino serial monitor
  Serial.begin(9600,SERIAL_8N1 );
  Serial.println("Arduino ready");
}

void loop() 
{
  // Read from serial 
  if (Serial.available())
  {
      c = Serial.read();
      if      (c=='1') { digitalWrite(LED_PIN, HIGH); Serial.println("LED is ON"); }
      else if (c=='0') { digitalWrite(LED_PIN, LOW);  Serial.println("LED is OFF");}
  }
}

Connect an Arduino, upload the above code.

Open Simple Serial Monitor by double clicking the main file

The first time you run SimpleSerialMonitor you may get a security warning. See below.

Simple Serial Monitor will open

I have used the program before and there are previous settings which have been loaded. The settings are kept in the simpleSerial.ini file. If simpleSerial.ini does not exist it will be created when the program is run.

If System Messages is checked, you will see a “Serial port open” message in red.
If the Arduino is connected correctly, it will restart and send a “Arduino ready” message.

Congrats. You are connected.

Security Warning

Simple Serial Monitor is not signed and therefore Windows will show a warning the first time you run the program. If you don’t like to run random unsigned code you can download the source code and use Visual Studio to compile it yourself.

The Visual Basic Program

The program is fairly simple. There is one form and one page of code. Things like the serial port and the timers are included in the form. A slide out settings panel is embedded within the form.

I won’t do a code run through as I have included comments in the code to explain things. However, if you have a question leave a comment below.
The best way to see the code is to download the project files and view in Visual Studio, however, if you want a quick look click here to open the code in a separate window (displays as a flat text file).

Downloads

Ready To Run Binary

Simple Simple Monitor V1.0.0.3
The download is a zip file. Unpack and double click the main file to run.
The app is not signed and you may get a Windows security warning when you first run.

Visual Basic.NET Source Files

Created in Visual Studio 2022, Visual Basic.NET (Framework) with NET 4.8
Simple Serial Monitor V1.0.0.3 Visual Basic.NET source files

Change log

V1.0.0.1
Initial release

V1.0.0.2
Bug fix: baud rate not updating on app load
Added: save COM port
The arrays used to store the combobox values are now global
Added: local variables to help make the code a little bit more clearer

V1.0.0.3
Bug fix: fixed an issue when no saved settings file found on start
Added: Help menu link to this web page

Visual Studio 2022

Visual Studio 2022 comes in several flavors including a free community edition (free for individuals, in a classroom learning environment, for academic research, or for contributing to open source projects).