OLD - RFIDuino Hello World 3

This is an old version of the tutorial for reference purposes. It has been replaced with RFIDuino Hello World


Up until now, our code has been looking for whether or not a tag is present. While the tag's ID number has been stored and used to verify a tag read, we have not output that data anywhere. Our third Hello World program will read the ID of the tag, and send it back to the computer. This will be a useful utility for recording our tag's ID numbers.


  1. Connect your RFIDuino as shown.
  2. Load RFIDuino_helloworld3 onto your board. You can find this sketch under
  3. Once loaded, you can leave your board connected to your computer - you will need this connection to power the board and to communicate with the computer
  4. Open the Serial Monitor. The serial monitor should be set to its default settings ('No Line ending', 9600 baud)
  5. Swipe a tag across the RFIDuino antenna. The green light will light up and your buzzer will make a noise, like in the previous example.
  6. The Serial Monitor will display 5 numbers. These numbers make up the ID of your tag.
  7. Copy down these number for future use. It can be handy to write the ID on a sticky note and attach it to the tag. NOTE: You will need the ID for at least one tag for the next tutorial.

Code Overview

The code for RFIDuino_helloWorld3 is almost identical to the code for RFIDuino_helloWorld2. Both sketches read a tag, verify it, and activate an LED and buzzer. The difference is that when RFIDuino_helloWorld3 activates those devices, it also sends out a message to your computer containing the ID for your tag.

EXTRA CREDIT: Modify the program so that the buzzer and lights no longer activate when a tag is read
EXTRA CREDIT 2: Modify the serial output so that it reads "Your tag Number is:xx,xx,xx,xx,xx"
Download Solution Files

RFIDuino Functions used in this example

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