Password Protected Secret Telling Arduino!


Introduction: Password Protected Secret Telling Arduino!

About: Hey YOU! Yeah, I'm talking to you who is reading this. Send me ideas for instructables, like things that you are wondering how to make or build, or really anything electronically related, and I'll get back t...

I was fooling around with my Arduino UNO and started making some cool things. One of them was a password protected secret telling Arduino! You don't need anything but a computer and an Arduino!

Step 1: Programming

This is the code I used!
void setup() {
pinMode(13, OUTPUT);
  Serial.println("HELLO WORLD!!!!!!!!!!!!!!!!!");
  Serial.println("I am Arduino!");
    Serial.println("Input the correct passcode and I will tell you the secret!");

void loop()  {
const char passcode = 'lolification';

    if ( == passcode) {
        Serial.println("I want Pizza"); //input secret line one here here
        Serial.println("I am Cold");//just copy paste these with the delays to keep on adding lines
        Serial.println("He broke an office computer!"); 
        Serial.println("I like when people program me!!!!!"); 
        goto start;

Step 2: HAVE FUN!

I had lots of fun when I made this project! You can play Capture The Secret with this. You need two different papers with codes on them. Each team inputs the codes in to the Password field on Arduino. You compile and program Open Serial Port and close main Arduino so they can not cheat. each side has opposite computers and have to find the paper to find the secret. The Secret is an object they have to find as well if you get tagged on the opposite team's territory then you have to go to the jail.

Look at some of my other projects at



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    There is a problem...if i send a great quantity of raw data, it reveals the secret, i dont now why, try by yourself...i solved the problem removing the cycle start, becouse void loop is already a cycle....

    1 reply

    Thank-you for that brilliant observation.

    Like if you using RFID's for a door, you could store your RFIDs information, copy it to another card. Delete that card out of the memory?

    1 reply

    Theoretically, yes but it wouldn't be the way you are thinking of it. It would be more like, the other card would still have the same ID, but when read its processed the same as a valid card. Thanks :D

    like... how would you program it to save, copy , and delete...

    2 replies

    What do you mean by save copy and delete (like what)?

    stored information.

    Wow thats pretty damn cool. Im new to C++ or C, i never understood where does all this code pop up from? Like how do you know that the Arduino will respond properly to what you tell it to do? like the pins and the analog stuff. Is there something i can get. Or is it more simple than i think? My C++ is basic... i can't write anything. But I understand some things. Just not enough.

    1 reply

    Ok this is very simple, First all you do is basically learn from the examples, then you make your own codes. Examples can be learned from by copying the code (not copy paste). Really to tell the truth, I need to test the code several times until I get it to work properly. An example of a code that is doesn't work the way it should is, in algorithm 1. I stopped trying to make that code work right because sometimes it is better to redo the whole thing. Thanks :D

    yes, I made it one day when I was bored in my Mom's office