Thursday, August 28, 2014

Adding a switch to the battery hungry Roomba Lighthouse/Virtualwall

I'm the proud owner of an iRobots Roomba 780. Included in the package there are 2 Lighthouse/Virtualwall used to put some limits to the Roomba willingness to clean the whole house (falling down the stair in the process...).

The Roomba's Lighthouse get the job done, but they have a defect: the battery last only 2 months.

And why do they last so little? It's easy: because  there is no switch, the Roomba's lighthouse are always on.

Let me think... my Roomba works about 6 hours/week... and it's Lighthouse receive and emit signal for 168 hours/week (24*7=168).
This doesn't make sense to me...

So I hacked a Lighthouse and added a switch to it.

The rest of this post is divided in 3 sections:
1) How to dismantle an iRobots Roomba Lighthouse/Virtualwall
2) How to NOT glue a switch with hot glue
3) How to CORRECTLY glue a switch with hot glue, to a Roomba Lighthouse

So, first things first:
1 - How to dismantle an iRobots Roomba Lighthouse/Virtualwall

Here is the Roomba Lighthouse

The top piece of plastic is hooked to the lower part with 4 plastic clip, in the 4 corner.

You can then remove all the 5 screws.

Then you can lift up the top part.

 And you are left with this:

 The Roomba Lighthouse dismantled:

2 - How to NOT glue a switch with hot glue

The hack to add a switch seemed ridiculously easy: cut  the red wire, and put a switch in between.
But when you think a job is dead easy, the mistake is waiting to happen...

So, here is the switch, salvaged from a broken ADSL router:

After some cutting/desoldering, I have a usable switch:

 I tough I would place the switch there:

Something like that, but with a hole for the switch:

So I made the hole, and I glued the switch with with hot glue... and when I pushed the switch on it's new hot-glue bed... the hot glue happily entered INSIDE the switch trough the switch venting hole... :-|

Here is the top of the switch, with the (now glue-filled) venting hole.

And this is the inside of the switch: a total loss.

3 - How to CORRECTLY glue a switch with hot glue, to a Roomba Lighthouse

So, let's go on with the Plan B: use  another switch I had lying around, and glue it in the correct way.

Here is the new switch connected to the Lighthouse.

This switch is bigger, it wont fit inside the lighthouse, so I created a plane spot (with some hot glue) on the external side of the Lighthouse.

Now, after the previous failure, I covered any hole in the switch BEFORE gluing it. :-)

And here is the glued switch in my brand new Roomba Franken -Lighthouse

 Now, some black tape to make it look a little better:

And I'm done!
My Roomba Lighthouse finally finished eating my batteries.
Now it's an Eco-friendly Lighthouse :-)