A page to keep track of some details about the green roomba in the space.

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I saw a The Roomba when I visited, what’s your plan to do with it?

So I recently purchased this Roomba:

Currently, I am unable to successfully send a command to the Roomba and see any output (LEDs, sound, motor movement.

At a best guess this Roomba is part of the 400 series. You can find the SCI documentation for this series here:
irobot Roomba Serial Command Interface (SCI) Specification.pdf (261.2 KB)

In an attempt to prepare for running a microcontroller off the Roomba’s power supply, I have started putting the following together:
Still need to add the header for 5V (just before the LED’s resistor.


It is worth noting that the Roomba’s battery doesn’t work. I have attached a cable so we can power it from an external power supply:

I have attached this cable using an XT60 connector, so we should be able to swap it out for an actual batter in the future:

I believe the Roomba needs somewhere between 14 - 16.5v but double check the specification if you are unsure:

The battery contacts are also a little broken. If you want to, feel free to fix it :slight_smile:

To make a life a little easier for anyone else wanting to play around with this, i have stored the components in Roomba’s dust tray:

If you want to make any serious modification to the Roomba, please give me a shout first. But for the most part, feel free to play around with it if you want.

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Currently, just trying to control it over its serial connection.

Of possible use?

Includes info on how to use Roomba as a theremin

Sure you’re using an uprated regulator such as the 78S05?

Yeah the room a book is actually what I was following (with some googling as well) :slight_smile:

If I remember correctly I think the regulator supports up to 30v in. I’ll get the number later today.

That’s cool. I plan to come on Friday. I wonder if you could replace the mechanical front bumper with proximity sensors.

hacking_roomba.pdf (7.9 MB)

So newer models have both. As they approach an obstacle the slowdown a little.

The regulator is L7805CV by the looks of things.

Ok, I’ll be making my way to the meeting. Be seeing you.


Had a pretty good night on Friday, managed to send some request to the Roomba that actually caused it to move.

I’ll add some pictures and stuff tomorrow


So a productive night on Friday, managed to send some simple commands to the Roomba over a COM/serial.

To make use of the bluetooth module, I needed to change it’s baud rate to 57600. I followed the following tutorials to do this:



Now I just need to start retrieving data from the Roomba, but for that we need to step down the 5V TX to 3.3V.

Could use a LD1117 800mA low-dropout regulator. Buy from Cpc Farnell, Rapid Electronics or Cricklewood Electronics. There is also ESR Components for single orders. For a single data line a voltage limited device such as a zener diode may suffice or it may be possible to use a resistance divider- just sort out what current you require over 4mA to 16mA.

Have ordered a replacement battery, should be here next week :slight_smile: