Thursday, January 13, 2011


I spent some Christmas money on an obviously named "Rootooth" (A Bluetooth interface for the Roomba) from, only to be frustrated by a lack of documentation (and, admittedly, knowledge on my part).  The Rootooth works to a point - the point at which you pair it with your other Bluetooth device (Tried with my Desktop computer and DroidX).  The various documentation states that the passkey for pairing is "default", but may also be "1234" or "0000".  So far, in repeated trials, none work.  I am now trying lottery numbers and birthdays.  Arrrgh.

I did forgo setting up a hardwired serial connection in the interest of expediency.  Mini DIN 8/7 pin cables are slightly difficult to find (the Apple store has them, but wants $25-30.00 for them!!!  CompUSA has them for $2.00 each).  I am waiting on my shipment from CompUSA.  And so waits the serial connection troubleshooting that they will allow.  Arrrgh.

Also come to light is that the 500 series Roombas implement a different (expanded?) version of the Roomba Open Interface (ROI, formerly Serial Communication Interface - SCI).  Which implies that the 400 series Roomba (Fun Gus) I have been trying to interface with the Rootooth may utilize a retarded version of the ROI.  Much of what has been written about "Hacking Roomba" is several years old, and iRobot seems to have abandoned online support of the ROI for consumer Roomba (Roombas?  Roombi?), in lieu of pushing the experimenter / hacker to the Roomba Create.  Arrrgh.

As I have mentioned, my Roomba 530 (Dirty Gertie) is smarter and faster, while my Romba 400 (Fun Gus) is more brutish in its approach.  Even though Gus sports an IR detector on the top of his bumper like all Roomba, he seemingly ignores Virtual Walls and gets stuck in a couple of spots around the house.  As to the Rootooth, it receives power when plugged in, but I am not confident that the serial connection is patent.  Where are those serial cables?  Arrrgh.

2010-12-16_23-01-12_898I haven't touched the Schlembot in a few days.  There is some glitch in the "TurnCounterClockWise" routine that interfaces with the Pololu serial motor controller.  Maybe some time and distance will provide clarity when next I bang on it.   Arrrgh.

But, as I type this, Gertie and Gus are dervishing on the floor, sucking and sweeping up the detritis of our domesticity, doing what they were (primarily) designed to do, and doing it well.  And that pleases me.

Friday, January 7, 2011

iRobot Looj

Not as charmingly named as the Roomba, Looj is iRobot's gutter cleaning robot.  Like the robot vacuum cleaner, I think this is another perfect application for technology. I say this as a man with a gutter problem to solve. 

The Looj comes with a battery-powered remote (2 x AAA), a 7.2V NiCad battery pack (very robust), with wall charger, and a sweeper / "auger" assembly. 

All wear items are replaceable. 

Reportedly very good at cleaning gutters.

Looj is NOT autonomous.  Must be controlled by a human with the remote.  As I write this, I am charging the batteries.  Performance report to follow. 

Saturday, January 1, 2011

Schlembot Motor Test and Excellent Power Supply

After weeks of fiddling around with building a VEX-based drive system for the robot, its power supply, Pololu interface, the servo and the case for the Ping)))  module, and just generally thinking about the Schlembot (not to mention The Holidays, and 417duino prototyping)...  it's time to write some Arduino code and make some shit happen.  This is a basic forward / backwards loop, just to monkey with motor speed and equalization.  It seems the right motor has a little more torque for some reason and kicks the whole robot to the left when going forward or reverse.  I think I can compensate for that by increasing the left motor speed by a tiny bit.  The servo wants to jerk around a little bit from line noise in the 5V power supply, so I put in some purposeful code to make the servo scan left-center-right.  The Ping module in the rotating project case isn't doing anything useful at the moment, just going along for a ride. 

I used my DroidX camcorder app to take this video - it's like 49MB in size. Crazy.

Below is the latest incarnation of the Schlaboratory Power Supply, incorporating Pololu motor control on the good old Radio Shack 276-150 PCB. 417, natch. I used this power supply with my lego / Basic Stamp robots and it performed very well. It has integral ports for powering servo motors and supplying a logic control signal. Vin could be anything between 7 and 20 (some say 35) volts.  I'm using a six-pack of 1.5V C cells to provide a nominal 9V.  9V out to Arduino module (which has its own on-board voltage regulator), the 5V from this power supply is for Pololu logic power, servos, and the breadboard.  The 7805 voltage regulator wastes the excess voltage as heat, but is simpler to implement than a switching regulator.  Good enough compromise for my nefarious purposes. 

Power supply  and pololu schematic

Happy New Year!

Here's hoping that the future smiles on you and that the forces of entropy and chaos do not factor into your reality.  On that note, here's a photo of the crap that the Roombas vac'ed up today.  I know, effing gross, and that's after about ten vacuumings of the house.  The Roombas just keep working. 

So, if you wonder if the Roomba actually works, look at this pile of crap and know it's true. 

Coming soon - bluetooth and Arduino-compatible control modules, bending the Roomba to the will of Schlaboratory.  Stay tuned.