### Author:  [@remi\_chen](https://discourse.processing.org/u/remi_chen)
#### Post date: [April 15, 2022, 2:59pm UTC](https://discourse.processing.org/t/coding-problem-using-processing-with-arduino/36354/1 "2022-04-15T14:59:53Z")
Hi guys! Recently, I am working on an art project that needs Processing and Arduino. Now that I have some questions, I want to turn the following flowchart into automatic code behavior. I already have some basic code and it works. But I don’t know how to automatically get the updated QR code data and update the header file through the code in Processing. Can anybody help me?
Here’s the code in Processing :
```auto
// THIS IS NOT ARDUINO CODE! Runs in Processing IDE (www.processing.org).
// Convert image to C header file suitable for the Adafruit_Thermal library.
void setup() {
// Select and load image
selectInput("Select image file to convert:", "processImage");
}
void processImage(File image) {
String filename, basename;
PImage img;
PrintWriter output;
int pixelNum, byteNum, bytesOnLine = 99,
x, y, b, rowBytes, totalBytes, lastBit, sum;
println("Loading image...");
filename = image.getPath();
img = loadImage(image.getPath());
// Morph filename into output filename and base name for data
x = filename.lastIndexOf('.');
if(x > 0) filename = filename.substring(0, x); // Strip current extension
x = filename.lastIndexOf('/');
if(x > 0) basename = filename.substring(x + 1); // Strip path
else basename = filename;
filename += ".h"; // Append '.h' to output filename
println("Writing output to " + filename);
// Calculate output size
rowBytes = (img.width + 7) / 8;
totalBytes = rowBytes * img.height;
// Convert image to B&W, make pixels readable
img.filter(THRESHOLD);
img.loadPixels();
// Open header file for output (NOTE: WILL CLOBBER EXISTING .H FILE, if any)
output = createWriter(filename);
// Write image dimensions and beginning of array
output.println("#ifndef _" + basename + "_h_");
output.println("#define _" + basename + "_h_");
output.println();
output.println("#define " + basename + "_width " + img.width);
output.println("#define " + basename + "_height " + img.height);
output.println();
output.print("static const uint8_t PROGMEM " + basename + "_data[] = {");
// Generate body of array
for(pixelNum=byteNum=y=0; y=lastBit; b >>= 1) { // Each pixel within block...
if((img.pixels[pixelNum++] & 1) == 0) sum |= b; // If black pixel, set bit
}
if(++bytesOnLine >= 10) { // Wrap nicely
output.print("\n ");
bytesOnLine = 0;
}
output.format(" 0x%02X", sum); // Write accumulated bits
if(++byteNum < totalBytes) output.print(',');
}
}
// End array, close file, exit program
output.println();
output.println("};");
output.println();
output.println("#endif // _" + basename + "_h_");
output.flush();
output.close();
println("Done!");
exit();
}
```
Here’s the code in Arduino:
```auto
#include "Adafruit_Thermal.h"
#include "QRCODE.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
const int Pushbutton = 3;
int value = 0;
int debounce_delay = 300; //Debounce delay
void setup() {
pinMode (Pushbutton, INPUT);
pinMode (7, OUTPUT);
mySerial.begin(19200);
}
void loop() {
value = digitalRead(Pushbutton);
if (value == HIGH){
delay(debounce_delay);
digitalWrite(7, HIGH);
printer.begin();
printer.setSize('M');
printer.println(F("Royal College of Art"));
printer.setSize('S');
printer.println(F("Information Experience Design"));
printer.setLineHeight(50);
printer.printBitmap(QRCODE_width, QRCODE_height, QRCODE_data);
printer.setLineHeight(50);
printer.println(F("Enjoy your memory ghost!"));
printer.setLineHeight(150);
printer.println(F(" "));
printer.sleep(); // Tell printer to sleep
delay(3000L); // Sleep for 3 seconds
printer.wake(); // MUST wake() before printing again, even if reset
printer.setDefault(); // Restore printer to defaults
}
}
```
---
### Author:  [@ChengkaiXu](https://discourse.processing.org/u/ChengkaiXu)
#### Post date: [April 16, 2022, 6:01am UTC](https://discourse.processing.org/t/coding-problem-using-processing-with-arduino/36354/2 "2022-04-16T06:01:13Z")
Even though I am also studying Arduino with Processing right now, I think I could offer a possible solution based on my experience.
**Thoery Part:**
“.h” file is a library file for the coding language C. These files you’ve included in the beginning of your Arduino codes are complied into a “machine language”, and then send to the arduino board. This process means that when you click the run button in the Arduino IDE, the program is fixed, which means it will no longer read these “.h” again. To achieve the dynamic read&print process, “.json” file may be a relatively good choice, which have already been used for data storage for years.
**Pratical Suggestion**
If I understand your program workflow correctly, QRcode here is an input which will be read by the Processing program. Then the Processing program deliver that information to the Arduino for printing.
You may need to change the “.h” file part. Instead, all the QRcode data can be stored in a “.json” file as an array. Then, in the Arduino program, you can parse those data from the “.json” file dynamically.
**Library resources you may need:**
Processing Side: [https://processing.org/reference/JSONObject.html](https://processing.org/reference/JSONObject.html)
Arduino Side: [https://arduinojson.org/](https://arduinojson.org/)
---
### Author:  [@glv](https://discourse.processing.org/u/glv)
#### Post date: [April 18, 2022, 9:04pm UTC](https://discourse.processing.org/t/coding-problem-using-processing-with-arduino/36354/3 "2022-04-18T21:04:24Z")
Hello @remi_chen ,
Which Arduino are you using?
`:)`
---
### Author:  [@remi\_chen](https://discourse.processing.org/u/remi_chen)
#### Post date: [April 19, 2022, 1:01pm UTC](https://discourse.processing.org/t/coding-problem-using-processing-with-arduino/36354/4 "2022-04-19T13:01:54Z")
Hi Chengkai
Thank you for your reply! I still have some questions ,do you mind if I ask for your email? I would like to have more communication with u!
---
### Author:  [@remi\_chen](https://discourse.processing.org/u/remi_chen)
#### Post date: [April 19, 2022, 1:35pm UTC](https://discourse.processing.org/t/coding-problem-using-processing-with-arduino/36354/5 "2022-04-19T13:35:47Z")
Arduino IDE with mega 2560
---
### Author:  [@RichardDL](https://discourse.processing.org/u/RichardDL)
#### Post date: [April 20, 2022, 2:32pm UTC](https://discourse.processing.org/t/coding-problem-using-processing-with-arduino/36354/7 "2022-04-20T14:32:10Z")
The Mega has 3 extra real serial ports, you don’t need to use the Software Serial. See pin 14…