Roomba i7 Teardown: Why is there a waving cat with a lint roller inside?

Blog Comments
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I wasn’t planning to take apart a Roomba today, but when your kid greets you in the morning with, “Are we going to take apart mommy’s vacuum robot today?” it’s hard to say no.  So, I spent part of my day taking apart, documenting, and reassembling a Roomba i7 - the newest generation of the Roomba line, with persistent house maps, a far quieter blower, and quite the surprise waiting inside for the determined explorer!

This is a companion discussion topic for the original entry at https://www.sevarg.net/2018/12/30/roomba-i7-teardown-with-the-waving-cat/
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(Comments from Blogger)

2019-01-02 by zeroair

OOOh. I love a good teardown!!

Nice work here.

2019-01-02 by Russell Graves

Thanks!

I’ve done quite a few other teardowns as well: https://syonyk.blogspot.com/search/label/Teardowns

Mostly battery packs, but there’s some other stuff in there.

2019-01-29 by Scott Gardner

Great writeup! I don’t have anything to add on the technical side, but I think the cat is holding a collapsible telescope, rather than a lint roller. You can make out the eyepiece and the three-section body, and it even looks like there’s a crescent-shaped “reflection” molded into what would be the front lens.

2019-01-29 by Russell Graves

That is certainly possible!

2019-05-24 by Unknown

I wonder if that expansion port is for the i7+ where it can auto empty in to the bin.
https://icdn9.digitaltrends.com/image/roombai7-5-800x534-c.jpg

2019-06-08 by Nelson Cabrera

Nice teardown. The golden circle in the brush roller compartment is a piezo electric debris sensor, it detects the impact of larger debris like pebbles, cereal, etc on the plastic of the compartment and is used by the system to detect areas where extra power/time needs to be used.

2019-09-10 by Paul Jurczak

The floor sensor detect movement of the robot over the floor (XY velocity vector) to be used in VSLAM. It works like an optical mouse.

2020-08-23 by Jay

Anybody knows what piezo debris sensor is used in the roomba 671?

2020-10-27 by Unknown

Hi I have a Irobot 7 whit dead left wheel, do you have the schematic circuit for casuality?

2020-11-12 by Deb Baugher

Hi. Mine stopped charging. Even with a new IRobot battery. Can I send it to you? How can you find people that fix them. I’ve never had problems till this i7 and I love the darn thing.

2020-11-12 by Russell Graves

No, sorry. I don’t repair them. They’re consumer electronics, you buy a new one.

2020-12-11 by Unknown

Just saw this teardown, excellent. I hate the lame YT ones where you have to watch someone fumble around for what seems like forever, then provide no real info. Now we need a software teardown.:slight_smile: Of course,very not trivial. But from what I’ve found, the software is as cool as the hardware. It makes heavy use of AWS cloud services,Kinetics and Lambda being the more interesting. Oh, right, I’m an EE and CS guy, love hardware and software. Keep up the good work!

2020-12-11 by Unknown

Oh, forgot. Back to your battery pack terminal comments, many include terminals for a thermistor to monitor temperature for controlling charge rate. I’d expect the same for this one, required for fast-charge.

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For the ESD brush, is there a way to replace that? I’d like to lengthen mine because I feel like my S9 stops with an error 15 message, and I want to test if it’s because of excessive static electricity from my carpet.

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Could you just wedge a small copper wire in there if the brush isn’t sold?

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You could probably find a longer one and fit it, but I’ve no idea what would fit or not - my issue lately is that our grit seems to be grinding through a part of the “sweeper brush” base plate area… I’m not too happy with how expensive this thing has been to operate. With the trashed clean base from a bit of water, I think I quite literally could have hired a maid service once a week, for less money.

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Never really thought of it that way - but yes these devices are quite expensive when looked at it that way.

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This is an excellent teardown - exactly what I needed to pull mine apart (the only difficult part was figuring out how to get the top of the chassis open). I just thought I’d add one note: the main board does separate from the main chassis (sort of). The plastic welds hold the main board onto a plastic frame that is press fitted onto several posts on the main chassis. If you pry carefully under the frame at each of the posts a little bit at a time, the frame slides right off. From there it’s just a matter of disconnecting the cables on the underside of the board. The only wire I haven’t figured out yet is the one ESD wire you mentioned. But even without removing that wire for the time being, it was enough for me to careful pull the board to inspect the underside.

I hope that helps! Again, great teardown - very much appreciated!

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I actually know the answer to a few of those questions (I think)

  1. the “floor sensor” is an optical odometer sensor used to track itself on a what I can assume 2D coordinate plane (from my experiences with the IROBOT CREATE 3, it takes x, and y coordinates)
  2. the expansion port with the cat, this is used in the create 3 for the bluetooth and usb c module, the same port exists on my Roomba 960, so its on my bucket list to maybe try out the create 3 python web sdk with that (not sure if it will work as the create 3 is based on a Roomba i3, and it has a custom firmware designed for ROS2 and it does not perform normal Roomba functions like the create 2 did.) I did notice that your Roomba i7 looks almost identical to the create 3 on the inside without the camera so assuming hardware is the same I could get a regular i7 and flash create firmware on it.
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I have an iRobot i1 series and has never sealed properly. Tore it down and found the lever that activates the spring and pushes the tube to seal to the bag is broken. I’m going to file a warranty claim but need help reconnecting the wires from the motor. I am assuming that white goes to mot-n and red goes on the mot-L? I didn’t get a pic to make sure. Any help would be appreciated!

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That would be consistent with normal AC wiring practices, yes. White is always neutral, black or red are line.

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Thanks for your help!