New 5XX Foolproof Cliff Sensor Work around

[She'sMariaToMe]

Vic's copy paper work around worked great for my new Roomba 770" Maria". I have about 1400sf of hardwood floors and about 1200sf of Saltillo tile in the kitchen and halls. I noticed immediately that Maria didnt like my traditional Persian rugs that have black boarders. I have these rugs throughout my home and this was going to be a big problem.

After doing a little reading at the Irobot site I decided there had to be a way to defeat such a simple system. My great idea was masking tape over the cliff sensors. My home is a one story so I'm not concerned with her taking a fall. After my masking tape test failed I decided I would call Irobot. I was very disappointed when the tech told me there was nothing that could be done. I was really expecting a dip switch issue or even a software upgrade,and that would be that. Ok,so thats what the internet is for and bam, here I am.

I've allowed Maria to run a full cycle and she now Loves the persion rugs. She also found her way home but I could have lived with that.

My Mother has a 5xx that she dosnt use anymore due to clutter mainly. I think I will bring her home with me to do the guest end of the house. I think I will name her "Rosarrio", or maybe "Rosita".

Anyway, THANKS to everyone for your input. It's people like you that makes the internet infinitely usefull.

MeAndMariaohandRosita

[RSargeant]

Here's a slightly new variation on cliff sensor issues. My 560 suddenly fell out of love with the power dock and refused to couple! It would wiggle towards the dock as usual, mount the lip of the dock and then just stop. After a few seconds it would sound "unhappy" but not attempt to re-dock. Net result, battery didn't get recharged.

The inside of the front 2 cliff sensors seemed very dusty. Demolished the Roomba (boy, you have to take a LOT apart to get those sensors out), cleaned out the inside of the sensors, re-assembled - fixed!

Our whole apartment has dark wood floors and no cliffs, so my theory is that the black plastic of the dock was just darker enough together with the reduction in reflected infrared caused by the dust for the firmware to yell "cliff" and stop the Roomba.

Maybe useful to others.

Richard
Switzerland

[robog33k]

My wife got a Roomba 650 for Christmas, and one of its first tasks was to vacuum the dining room. In our dining room is a small carpet in front of the door (little brother to the bigger ones in our living room and foyer), with a wonderful variety of geometric patterns on it. Patterns that caused the poor little 'bot to totally spaz.

Looking around on the Interwebs, I found this forum, and this thread (huzzah! Love this forum!!) And while the concept espoused here made perfect sense to me in general terms, the engineer in me was not satisfied with the solution as it was presented. So I set out to craft, what I think, is a better solution.

But first, why it didn't make sense to me. The cliff sensors each are made up of a pair of infrared (IR) transmitters (phototransistor) and receivers (photodiode), and that pair is separated by an opaque plastic "wall" between the 2 of them; look closely at your 'bot and you can see it running right down the middle, and extending just a tad (technical term) above the transparent window. Putting a piece of paper or aluminum foil over the window would do nothing to channel the IR light between the 2 sides; in fact, it would be more prone to block it. I'll speculate that the aluminum foil that worked for folks was loose and crinkly, with lots of little channels between the 2 sides. The calls for "high quality white paper" leads me to think that people were using thicker fiber stock, that gave the IR light plenty of room to channel through the paper, between the 2 sides of the sensor's chambers.

So, let's take a look at the IR light. My wife's phone just happens to have an IR mode, so here is the light being emitted from the transmitter:



What I figured we'd need was a "channel" of some sort, that would funnel the light from the transmitter's side to the receiver's side. So I tried a couple different pieces of straw to see which reflected the light best, and settled on this one:



What is it? It's the hard plastic straw from a water bottle. This particular one's made by CamelBak, and you can buy spare straws at various sporting good stores (I've bought mine at Dick's and Mountain High).



And it turns out, after trimming one to fit my bottle, I had just enough left over to be used for this task!



I cut this piece into 2 pieces, each about an inch long.



Then, I proceeded to cut them in half. After cutting off the tip of my left index finger by using a Really Sharp kitchen knife (I'll spare you the picture of blood all over the kitchen), I then got out my metal shears and cut them down one side:



then used the Really Sharp knife to cut the other side:



I now had 4 pieces of "IR channel" to apply to the 'bot's sensors.



I put a piece of scotch tape on each, with about ½" of overhang on one side, and ¾" on the other. The shorter piece went on the inside of the sensor, the longer side went on the outside.

Et voilá, the final result…



Tips:

• Make sure the tape is secure; I've already had one IR channel fall off because I didn't firmly press the tape down, and have a second about to come off too.
• If you use a different material, find a camera that will help you determine if the material is reflective in the infrared. Just because a material is opaque to your eye does not mean it won't be transparent to IR.
• Be careful using sharp knives. No, really!

I'm toying with the idea of supergluing these pieces in place; since they're open-ended channels, I can easily use a can of air to blow out any accumulated dust within.

Hope my adventure helps someone! Even if it's just to remind people to be safe when playing with knives!

[vic7767]

robog33k, nice update to this thread. Anything surface wise that can reflect the IR signal back to the receiver is a great work-around.

[gregjsmith]

I have used the same straw trick, except I use regular stars found from fast food drinks.

I tape them on with blue painters tape with the bottom cover off, then put the cover on which overlaps the tape.

[iMayne]

Vic, what's the reason for the two white papers just above the battery?

[vic7767]

That was to demonstrate the shape of the paper inserts.

[Metroshica]

Created an account just so I could thank robog33k! I tried all sorts of methods, aluminum foil, masking tape, paper suggested by vic, and I could not get my Roomba to work. I only succeeded in my Roomba not moving at all and consistently telling me to "move roomba to new location, then press clean to restart". I just happened to have a water bottle similar to robog33k, cut it up and applied it like he said, and it worked perfectly! Thank you very much for this solution, my wife and I just bought a beautiful new rug, but the black in the design completely befuddled our Roomba 560. Did not want to go have to buy a manual vacuum, you saved us a good amount of money robog33k.

[aurickle]

I'm so glad I found this thread! I love my Roomba but it has always had trouble with certain areas of my rugs. I'd always thought it was just not liking the wires that run under the rug to my surround sound speakers, although that didn't make a whole lot of sense to me because the resulting bump is pretty much nonexistent. I never thought of the cliff sensors being the problem, but as soon as I read this I realized that had to be the case.

I tried the foil method initially and my Roomba immediately demanded to be moved. But robog33k's suggestion gave me an idea. I didn't have any straws around -- but I do have some zip-lock baggies. It occurred to me that the channel that lets these lock should work the same way as a straw, but even better because of how little depth the channel has. It would create a tunnel for the light to reflect through, but with a profile almost as thin as the unmodified unit.

I simply opened a baggie and cut the channel strip from one side. That I cut into six short lengths (because the 700 series Roomba has six cliff sensors). I laid each segment onto a sensor with the ridges facing down, creating a very thin tunnel. Then I used silver duct tape to fasten the segment to the Roomba.

It worked a treat! I put the Roomba onto my area rug in the section where it ALWAYS gets hung up. I think my next step will be to shellac the edges of the duct tape so as to guarantee that they'll never peel up. That will also remove any risk of dust getting trapped. I know it would prevent me from ever being able to send the Roomba in for warranty work. To me that's a small price to pay for FINALLY not having to listen for the Roomba to complain about the rug anymore.

Thanks for the suggestions!