Thanks, it looked like the ticket, so I already went ahead and ordered two to set up his-n-hers detection for my queen bed.
I also just found this link for what seems to be the latest cat’s ass in detection!
Upon reading more about mmWave radar though, I am under the impression it is still a motion sensor, just many MANY times more sensitive…
Been awhile since I looked at this thread seems lots of people have moved on with pcbs etc. I use a custom pcb on mine (which works great) couple of things that spring to mind reading through.
BME280 definitely needs to be off board, I connect mine with DuPont wires to header as it was several degrees off mounted on board.
The use of single set resistors, I don’t do this with mine I used trim pots, makes setting a breeze and allows easy tweaking over period of time to account for different weights of bedding and to dial out effects of cats sleeping on the bed in day time, Didn’t even bother measuring resistance on the last one I installed, 100k trim point turned down until voltage dropped below 3 out of bed. Not a clue what the resistance is, no need to know,
It’s a brilliant project, the amount of automations I have built based on this, genius idea by op.
Just wanted to send a warm thank you to @tom_l for an outstanding project! Built one this afternoon for the master bedroom and it works beautifully. My wife thought it was pure magic when she tested getting in and out of bed and watched everything turn on and off.
Used an ESP32 pico M5Atom Lite and Proto kit I had leftover from another project which turned out to be a perfect fit for this simple circuit. Thought I’d share!
Hah I know I know; the M5 Atom lite only has one ADC pin header unfortunately, so my first pass was just the one side of the bed. But! I realized that the Grove port has a second ADC pin, and you gave me the motivation to redo it! Finished this morning with a spare board and now have both sides of the bed covered and working perfectly.
I’m currently very satisfied with my little PCB - don’t looks that clean but I’ve put the whole thing into a surface mounted box and mounted it with reusable cable ties to the slats of my bed. And what should I say - it’s working wonderfully
Thanks for this great writeup! I tried this years ago and for some reason failed, I guess I didn’t know enough about electronics yet. Now I have a sensor for each side of the bed and it’s working perfectly!
Note, I had to use a much higher R1, probably because my mattress weighs much less. With such a light load it was harder to get a reading for the base value of the FSR, so I used 5 Mohm for my calculation and that seems to have worked out great. My resulting resistor that I chose was 680 Kohm.
Got it semi installed…under the mattress is complete but external circuitry still very temporary! Two FSRs secured and wired but only 1 connected to a D1 mini; an ESP32 is on order. I started with a 470K resistor but voltages in/out of bed very low (sub 1.0v). Worked my way down to a 50K resistor and have in bed voltages of 0.3-0.4 and out of bed 2.0-2.4. Judging by everything posted above, I would seem to be in the ballpark but will try smaller value resistors to get the out-of-bed voltage closer to 3.0 volts.
I don’t think I would use those Dupont wires for this use especially under the mattress that’s going to be moving around a lot. I think reliability would be a major issue.
Thanks to everyone for all the contributions. You guys convinced me to switch from a weight sensor to the FSR Bed sensor, which is a much more reliable and easier solution, I love it.
I want to give something back to the community, so I am sharing my ESP-Home code which I modified for 2 bed sides, faster sensor response by using the exponential_moving_average and added some nicer Icons and defined the correct device classes. (with sensor names in German)
Do you mean the friction fit connector or the wires in general? There’s only about an inch or two of wiring taped down. Two fsr’s join a 3 conductor RGB ribbon cable that then goes below the slats and is secured alongside the center beam.
The mattress itself is quite heavy and only has +/- 1 in of play inside the frame…