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DIY Roomba Virtual Wall

Recently, my Roomba virtual wall broke. Not sure what happened. I did a battery change, and the darn thing will not power up after the new batteries were inserted.

Anyway, while looking online for a new virtual wall to buy, I came across info on people making their own virtual walls. Here is a links dump:

Turns out it is extremely easy to produce the IR signal emitted by the virtual wall. It's basically 0.5ms mark, 7.5ms space, 3 times, followed by 132ms of rest (based on the info given here), over a 38KHz modulation frequency.

I decided to test the idea using a simple ATtiny85-based circuit on the breadboard:

The test program is as follows:

#include <Arduino.h>
#include <tiny_IRremote.h>

IRsend irsend;

void setup() {

void loop() {
  for (int i=0; i<3; i++) {

My initial attempt using the IRRemote library found in Arduino's Library Manager didn't work, though ATtiny85 is supposed to be supported.

Being the lazy bum that I am, instead of trying to debug the library, I simply googled around and found another IR remote library called tiny_IRremote. I downloaded the library and changed the include file, and to my amazement, the test circuit worked on first try!

The IR LED that I was using on the breadboard was the one salvaged from the broken virtual wall. I also tested another IR LED that I removed from an old TV remote, as well as a IR LED that I found in the original Arduino kit purchased many years back. They all worked without a problem (at least with the two 500-series Roomba in my possession).

Now that the proof-of-concept works, I am going to build a replacement Roomba virtual wall with the ATtiny85.


  1. Missing the declaration of irsend in this little example

    1. Find in tiny_IRremote:

    2. Thanks for your answer. I don't think you got my point; I'm aware that I've to use the lib from this Gist; but I just pointed out that in this POF code the declaration of irsend object is missing:

      IRsend irsend; // This was missing

      (#include is missing too by the way)

      Thanks for this project !

    3. okaayyy ... for some reasons some parts are deleted on comments ... So again, without angle brackets 🤥

      #include tiny_IRremote.h // imagine angle brackets ...
      IRsend irsend; // <-- This was missing

      (#include Arduino.h is missing too by the way; again imagine angle brackets)

    4. Ah, I see! I have fixed up the code. Thanks for pointing out the omissions!


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