Interface and Application Programming

Individual Assignment: Tkinter, PySerial, and 16x2 LCD

Objective

Develop a Python application using Tkinter and PySerial to send text to a 16x2 LCD via an Arduino.

Device Description

• Communication: PySerial to Arduino.


• Install Python



• Python Installation succsessful



• Checking Python Version



• Install pyserial



• Verifying Tkinter



• Testing Python libraries


• Code Snippet

                    import serial
                    import tkinter
                    print("pyserial version:", serial.__version__)
                    print("Tkinter version:", tkinter.TkVersion)
                    root = tkinter.Tk()
                    root.title("Test")
                    root.mainloop()
                







Verify LCD and RP2040 Setup (Arduino IDE)

• Confirm Wiring: I2C LCD
• SDA → GP8
• SCL → GP9
• VCC → 5V
• GND → GND



Code Snippet: LCD 'Ready' Test code on Arduino IDE




#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
void setup() {
  lcd.init();
  lcd.backlight();
  Serial.begin(9600);
  lcd.clear();
  lcd.print("Ready...");
  delay(2000);
  lcd.clear();
}
void loop() {
  if (Serial.available()) {
    lcd.clear();
    String input = Serial.readStringUntil('\n');
    if (input.length() <= 16) {
      lcd.setCursor(0, 0);
      lcd.print(input);
    } else {
      lcd.setCursor(0, 0);
      lcd.print(input.substring(0, 16));
      lcd.setCursor(0, 1);
      lcd.print(input.substring(16, 32));
    }
  }
}
                








Input: Text via Tkinter GUI.



• Tkinter Code Snippet



import tkinter as tk
from tkinter import messagebox
import serial
import time

try:
    ser = serial.Serial('COM5', 9600, timeout=1)  # Matches your port
    time.sleep(2)  # Wait for RP2040 to initialize
except serial.SerialException as e:
    messagebox.showerror("Error", f"Serial port not found: {e}")
    exit()

root = tk.Tk()
root.title("RP2040 LCD Control")
root.geometry("300x200")

label = tk.Label(root, text="Enter text for LCD (max 32 chars):")
label.pack(pady=5)

entry = tk.Entry(root, width=30)
entry.pack(pady=5)

status_label = tk.Label(root, text="Ready")
status_label.pack(pady=5)

def send_text():
    try:
        text = entry.get()
        if len(text) > 32:
            text = text[:32]
        ser.write(f"TEXT:{text}\n".encode())
        ser.flush()
        response = ser.readline().decode().strip()
        if response == "OK":
            status_label.config(text=f"Sent: {text}")
            entry.delete(0, tk.END)
        else:
            messagebox.showerror("Error", "LCD write failed")
    except serial.SerialException as e:
        messagebox.showerror("Error", f"Serial communication failed: {e}")

def clear_lcd():
    try:
        ser.write(b"TEXT:\n")
        ser.flush()
        response = ser.readline().decode().strip()
        if response == "OK":
            status_label.config(text="LCD cleared")
        else:
            messagebox.showerror("Error", "LCD clear failed")
    except serial.SerialException as e:
        messagebox.showerror("Error", f"Serial communication failed: {e}")

send_button = tk.Button(root, text="Send to LCD", command=send_text)
send_button.pack(pady=5)

clear_button = tk.Button(root, text="Clear LCD", command=clear_lcd)
clear_button.pack(pady=5)

root.mainloop()
try:
    ser.close()
except:
    pass

            




• Output: 16x2 LCD (HD44780-compatible) on Arduino.