Arduino

This article is about Arduino boards and how can your Lazarus/FPC application communicate with them.

Serial communication

There are many ways for serial communication in Lazarus and FPC.

Lazarus serial application

We will use Synaser library in this example. Create Lazarus application with one form and two buttons. Include Synaser unit and add Synapse package as a new requirement to your project. In OnClick event of both buttons put something like this:

procedure TForm1.Button1Click(Sender: TObject);
var
  ser: TBlockSerial;
begin
  ser := TBlockSerial.Create;
  try
    ser.Connect('COM1'); // write here Arduino COM port number (on linux it's something like '/dev/ttyUSB0')
    Sleep(250);
    ser.config(9600, 8, 'N', SB1, False, False);
    ser.SendString('on' + #13#10); // button 2 should have 'off' here
  finally
    ser.free;
  end;
end;

Arduino serial application

You can program your Arduino in several languages.

Minimal Arduino C sketch

You can follow this nice step by step tutorial. In short, you need to add a led with proper resistor to your input pin 13, compile and download this sketch to Arduino:

int led = 13; // Pin 13

void setup()
{
    pinMode(led, OUTPUT); // Set pin 13 as digital out

    // Start up serial connection
    Serial.begin(9600); // baud rate
    Serial.flush();
}

void loop()
{
    String input = "";

    // Read any serial input
    while (Serial.available() > 0)
    {
        input += (char) Serial.read(); // Read in one char at a time
        delay(5); // Delay for 5 ms so the next char has time to be received
    }

    if (input == "on")
    {
        digitalWrite(led, HIGH); // on
    }
    else if (input == "off")
    {
        digitalWrite(led, LOW); // off
    }
}

Ethernet communication

TBD

Lazarus ethernet application

TBD

Arduino ethernet application

TBD