Is My Roomba Afraid Of The Dark?

Roomba 960’s have cameras, and are afraid of the dark.

This week I learned something new: My Roomba 960 is afraid of the dark.

The mystery started when I noticed that Alfred (yes, we named him Alfred!) started finishing work early. Normally it takes almost an hour and a half to finish our house. But as winter wore on I noticed that time decreased until it only took 22 minutes.

HABITS AND ASSUMPTIONS

Having a smart home means not only learning about technology but also learning a bit about your own habits. It means learning that when simple rules meet the complexity of normal life, unexpected things will happen.

Like the poopocalypse of 2019, where we forgot to give Alfred the afternoon off when we left the house with our (nearly) house-broken dog at home. While Alfred is very smart about most aspects of the floor-cleaning business, he apparently does not have a poop sensor and doesn’t know when to quit when he encounters a steamy pile of goodness.

Poopocalypse 2019 Tracking Map

Since then, we’d come to a happy compromise: we’d schedule Alfred to run in the morning.

ALL IS WELL, UNTIL

The new schedule seemed to work for everyone. At 7am he’d start cleaning, and usually wrap up before 8:30. All was well until the last couple weeks when I started getting notifications that he’d stopped early.

I didn’t think much about it until it started consistently started happening. Robots don’t generally just cut out of work early like people might, so what is going on?

When I looked at the maps for each day, a trend started to appear.

At first Alfred did part of the living room before quitting. But then later it didn’t do the living room at all. I thought maybe Jenna was canceling it, but she said that she never cancelled it. It thought that perhaps it needed some extra cleaning, but that made no difference.

CAUGHT IN THE ACT

On Saturday morning, I saw what happened. I was in the kitchen with a cup of coffee working when Alfred finished the kitchen and went to start the living room. As he headed into the dark living room, he stopped, turned around, and just went back to home base… Then cheerily texted me to tell me he’d finished cleaning!

It turns out that the 960 and newer models have cameras to help it avoid obstacles and map the room. Those cameras only work when there is enough light to see.

Aha.

MYSTERY SOLVED

That makes sense but why the sudden change in the in the living room schedule? The answer to that mystery is another piece of automation: the living room lamp.

The lamp is scheduled to turn on at sunrise, and then turn off at 10 PM. During the winter the sun rises a little later each day, but Alfred dutifully starts his job at 7am.  

During the Summer it was already light when Alfred went to work so it didn’t really matter if the living room lamp was on or not. But it’s still dark during the Winter.

Apparently there was just enough illumination from the night lights for Alfred to navigate the kitchen and front room, but the living was just too dark unless the lamp was on.

So, Alfred looked in, said “Nope!” and went home. Mystery solved.