Roomba virtual wall project


Active Member
My house has an open floorplan on the 1st floor- while it isn't a real big area, it is more than a Roomba can handle, especially on one charge.

So my wife has been doing all sorts of things to keep it in one area at a time- using the virtual wall, laying chairs down, opening doors, etc. Works, but kind of a pain.

Buying multiple virtual walls would have worked, but you need to walk around and hit the buttons on all of them. . . plus they are big and not cheap.

So I thought heck, I should be able to make a virtual wall much smaller than that, and power all of them from a central point. . . I found this schematic-

and tacked the PCB alongside an amp board I was making anyways. Populated, it looks like this-

I had to tweak the values a bit to get the correct frequencies, and I needed to add a 33uF bulk cap once I ran my wires (farthest is about 40 feet from the supply). I used cat5 because I had it- ganged all the conductors into two bundles. Overkill, but there is very little drop. Each VW only draws about 30mA.

For mounting, I cut out a section of baseboard, drilled a small hole for the IR LED, and hollowed out the back for the PCB.

I used spare baseboard since I wanted a tight fit. Once I had all the pieces prepped, I popped off the existing baseboard, and chopped out a piece just big enough for my new section to squeeze into, then nailed those pieces back, while holding the new piece in so I could get a nice tight friction fit. (easy to remove the housing if I have any issues) Looks like this (don't mind the grime. :)

I need to pick up an appliance module to allow for remote control of the power supply from my Housebot touchscreen, and it will be complete!

Hey this is really cool. Making circuit boards is way beyond me.

Give me a PM if you would be interested in make some of these for me.


Thanks for the comments!

To anyone that wants to make their own- I would be willing to design a slightly more generic PCB (one that can take SMD or through hole) for all the components and publish the gerbs and such.

If there is a lot of distributed interest, I might be able to order boards and kit the parts, in order to get the volume somewhere reasonable. Have to see how much it would cost though- it may not end up a lot cheaper than buying used ones off ebay and ripping them apart. I leveraged an extensive junk collection.

I wish my house was too big. Thats one complaint I don't think you will ever hear from me. :) That is a really cool idea tho. Thanks for posting.
Hi all,

I believe that you could use a dual NE555 (NE556) where one oscillator would modulate the other oscillator. The NE556 goes for around $.50.

This would eliminate the need for the driver transistor as the NE555 has its own output transistor capable of carrying the necessary current to drive the LED.

Just a thought.

Squintz said:
I wish my house was too big. Thats one complaint I don't think you will ever hear from me. :) That is a really cool idea tho. Thanks for posting.
Not a sq footage problem- we've just found that the Roomba (at least the one we have) doesn't cover well when the space is complex- its tiny little brain can't hack it. It also doesn't really have enough charge to do a good job on more than a 15x15 room. The whole area I'm talking about is only about 34x15- I probably have one of the smaller houses on the forum, total is around 1700 sq ft.

Which battery do you have in the Roomba?

Our Roomba has the APS battery and can do at least two rooms that are 15X15.

If you are using the stock battery, I suggest that you upgrade to the APS battery.

Just a thought.

Still the stock- when it kicks, I will look into it. For now, not that big a deal. Getting the clutter picked up is much more of a hassle. ;-)
I just bought 4 new virtual walls on EBay for $20 shipped and man that must be one large area because my Roomba can clean 3 rooms down stairs which is about 1200 sq feet with no problems at all. Mine's over a year old and it still runs about and hour and a half. I'm still impressed with these little bots. Your setup is neat though but the work you went to is much more that tapping my 4 virtual walls with my toe :)
You must have way less grit than we do. Or maybe our dirt sensor is defective? It typically runs until dead. . .

At the time, I couldn't do much better than about $10 each, shipped. And I prefer the totally invisible look anyways. After hitting the junk box, and getting the free ride on the PCB, I spent about $1 in parts each. Did I mention I'm cheap?? ;-)

Never mind the cool factor!! Isn't that why we're here?
It would be nice to interface those VW with the ELK M1.

If you could force the roomba to go into a particular room by turning on and off VW, creating a trap to force it in that room for x amount of minutes before inverting the process and forcing it to return at it's base...
I was thinking about stuff like this for the future (esp with a bigger battery ;-). I could easily run individual power lines to each one to allow central control. You'd have to time it just right though, as the roomba will stop when it thinks the area is clear.

If you went all out, you could implement more stuff- like using the charging dock signal to lure it into the next room.