[danielheath]

I did a similar thing with a regular backlit computer screen.

It automatically shuts off after 30 seconds of inactivity.

I added a $3 webcam, and use openCV to detect motion. If three consecutive frames (sampled 0.5s apart) are each sufficiently difficult from the previous one, it attaches a virtual USB mouse, then moves it one pixel.

This wakes up the display whenever you walk past, then puts it back to sleep again when you stop moving.

The motion-detection pipeline uses less than 0.3% CPU on an intel N100 (6w TDP).

[jofzar]

You can probably just use a cheap motion sensor instead of the webcam if you wanted to. There so many now

[hipjiveguy]

If you have some to suggest, I'd love to hear it... TIA!

[bayesianbot]

Something like LD2410 [0]. IIRC there's newer ones that report accurate position and even heart beat rate, but I've forgotten the names of those..

[0] https://dronebotworkshop.com/ld2410c-human-sensor/

[IanCal]

Here’s one

https://thepihut.com/products/60ghz-mmwave-breathing-and-hea...

Same kind of tech but higher frequency.

[embedding-shape]

> The MR60BHA2 is a 60GHz wave sensor that detects breathing and heartbeat patterns. Using its radar technology, it can monitor vital signs without direct contact, even through materials like clothing or bedding. You can use it for sleep monitoring, health assessments, and presence detection.

This is kind of crazy, I had no idea this was a thing. And here I have PIR sensors all over the place and hacks around those, that definitively sounds much better. Besides being more expensive and weaker range, any drawbacks for using it for motion sensing?

[dimitri-vs]

What's your budget? https://en.tokyodevices.com/items/128

But seriously you can probably DIY something a lot cheaper.

[danielheath]

Found a few aliexpress sellers offering LD2410C's, but all cost 30% more than the webcam I used.