What I wanted to learn, and why it interested me: This week, I would like to explore the thermal printer. I want to learn how to use a thermal printer because I have seen people use it to print shipping labels and stickers. Through this topic, I can learn about how a thermal printer works while also learning about how to wire an Arduino to it.

Final outcome: The thermal printer prints a little script where the User gets to choose four designations to travel to.  Then, the user can press a button on the breadboard labeled A-D. Depending on the button letter, the thermal printer will print a plane ticket that corresponds to the options on the script. 

Process and reflection: 

First,  I started by experimenting with the thermal printer and Arduino commands. For the technical training, I made two buttons that would trigger the thermal printer to print out a haiku and an image of a house, respectively. The process was relatively straightforward, as the image of the house was already converted into a file that was readable for the thermal printer. For my final project, I wanted to wire multiple buttons to the thermal printer, where each button would trigger a print of a different plane ticket design to a destination of New York, Boston, Las Vegas, or Los Angeles. Throughout the process, I had some trouble with converting the images and fitting them into the memory of the Arduino because the image files were quite big. I had to shrink the size of the actual jpeg first and then put it into processing to convert it into a form that can go through the thermal printer. After several rounds of resizing with different parameters and mutiple conversions, I was able to get 4 files that printed out. However, due to the limited memory capacity of the Arduino, only two options can be choose from at once. 

/* 

60-223 Intro to Physical Computing, fall 2025

Domain-specific Skill Building exercise: Ticket to Adventure

This piece of code allows users to print out a series of 4 plane ticket designs with different destinations on them, depending on the button that is pressed. First, it prints out a script that welcomes the user to the printing center and explains the details of the options that each button maps to. When the button is pressed, the printer will print out the plane ticket corresponding to the button that is pressed. 

*/

#include "Adafruit_Thermal.h"

//ticket files

#include "NewYork3.h"

#include "LasVegas1.h"

#include "Boston3.h"

#include "LosAngeles3.h"

#include "SoftwareSerial.h"

#define TX_PIN 6 // Arduino transmit  YELLOW WIRE  labeled RX on printer

#define RX_PIN 5 // Arduino receive   GREEN WIRE   labeled TX on printer

SoftwareSerial mySerial(RX_PIN, TX_PIN); // Declare SoftwareSerial obj first

Adafruit_Thermal printer(&mySerial);     // Pass addr to printer constructor

//setting the pin values

const int BUTTONA = 12;

const int BUTTONB = 8;

const int BUTTONC = 9;

const int BUTTOND = 13;

void setup() {

 pinMode(7, OUTPUT); digitalWrite(7, LOW);

 mySerial.begin(9600);

 printer.begin();

 pinMode(BUTTONA, INPUT);

 pinMode(BUTTONB, INPUT);

 pinMode(BUTTONC, INPUT);

 pinMode(BUTTOND, INPUT);

//welcome message

 printer.println("Welcome to the travel printing center");

 printer.println("Are you ready for an unforgettable adventure?");

 printer.println("Where would you like to travel to?");

 printer.println("Here are the Options:");

 printer.println("A: New York");

 printer.println("B: Boston");

 printer.println("C: Las Vegas");

 printer.println("D: Los Angeles");

 printer.println("");

 printer.println("");

 printer.sleep();      // Tell printer to sleep

 delay(3000L);         // Sleep for 3 seconds

 printer.wake();       // MUST wake() before printing again, even if reset

 printer.setDefault();

}

void loop() {

//reading button values

 int buttonValA = digitalRead(BUTTONA);

 int buttonValB = digitalRead(BUTTONB);

 int buttonValC = digitalRead(BUTTONC);

 int buttonValD = digitalRead(BUTTOND);

//ticket to New York

 if (buttonValA == HIGH){

   printer.printBitmap(NewYork3_width, NewYork3_height, NewYork3_data);

 }

//ticket to Boston

 if (buttonValB == HIGH){

   printer.printBitmap(Boston3_width, Boston3_height, Boston3_data);

 }

//ticket to Las Vegas

 if (buttonValC == HIGH){

   printer.printBitmap(LasVegas_width, LasVegas_height, LasVegas_data);

 }

//ticket to Los Angeles

 if (buttonValD == HIGH){

   printer.printBitmap(LosAngeles3_width, LosAngeles3_height, LosAngeles3_data);

 }

}