Does anyone know of a small weight scale? I want to create a smart dog water bowl and a small scale (full sized ones for humans are too big and not as accurate)
I know "espresso" scales for weighing beans are small and accurate but unsure if anyone had any suggestions.
Searching for zigbee or matter scales just gives me smart scales with screens. I have yet to find one that would have a possible HA connection
#Small weight scale (to the gram)
fervent epoch
errant pumice
thought this was going to go a different way when i read the title...
are you not better of using a water level sensor?
fervent epoch
I didn't want to put anything in the bowl as he is a puppy and 100% will chew it/try and rip it out
errant pumice
you could use an extrasonic sensor at a distance
wait no
dont do that
dogs can hear ultrasonic
fervent epoch
dog screams violently "Wow, he hasn't drank water in hours"
errant pumice
lol yeah, realised that as i hit enter
what if you have a 2 chamber bowl 1 larger chamber for dog to dring from and 2nd chamber that you can put a level sensor inside but is closed off except for small halls to allow water to find its level (and a human usable access hatch for service). you could also put a hose onto the 2nd chamber which could use a value to auto refill
i see your point but i think you are going to struggle doing it by weight
also if it drops a toy in there or something it may show as full when actually empty (of water)
fervent epoch
I did think about that, however he hasn't ever put toys in his bowl, also I'd be able to see it. I walk by somewhat frequently and would notice a toy, but it can be hard to see the level of water
errant pumice
there are "non-contact liquid sensors" which you could put on the outside of the bowl rather than in it but you could have to do it in a way that he doesnt "disrupt" it
they work by capacitance i think
fervent epoch
Hmmm that could work. I'd have to look into how a non-contact liquid sensor would work. I plan on 3D printing a base for it so if it could work on the bottom
errant pumice
another idea might be a spring loaded switch in the base that can push the weight of the bowel but not the bowel filled with water. if you get the right spring value it might work. the bowl would pop up slightly when empty/low
a level sensor of some sort is probably the best option though
fervent epoch
I'd have to use something like a hall effect sensor for minor movement
He is 10lb's so he has a small bowl
But then I'd be concerned about it picking up movement from us walking or something
errant pumice
you could also get a "dog pressable" button and train him to use it i guess...
fervent epoch
I did find this scale that does connect to an app
https://hototools.com/products/smart-kitchen-scale
Downside it uses batteries
errant pumice
i suspect you would have to modify it. add constant power. make sure it doesnt auto off for inactivity etc...
fervent epoch
Ohhh auto off
yeah that would suck
I might have to buy my own scale components and build it
errant pumice
could add an esp32 to track when its on/off and "press" the button to switch it back on i guess but then your going right down the path of something thats not the right idea
calibration might be something else to worry about
fervent epoch
As long as I can tare the scale, I should be fine
errant pumice
ooo heres an idea. if you have a metal bowl you could measure its capacitance. the amount of water will change the capacitance
fervent epoch
I don't but I can get one
errant pumice
theres alot of variables involved but i dont see why it wouldnt work at least to some extent
fervent epoch
Seems like I'll need an ESP32 either way π
errant pumice
i am courious enough i may just give it a go π
fervent epoch
Glad I could give you a project idea lmao
errant pumice
ill be honest, i have the house to myself for a week starting an hour ago so am free to do random things. the projects are lining up
errant pumice
ignore the fact its called chair occupancy. i borrowed another project for a moment
i am not sure the detection is actually that different once its stablised
very much a "things balanced on each other" setup though so might be better if its fixed and doesnt have a long cable being used etc...
unable to totally comfirm POC but with a better setup it may work
now to put stuff away before i end up with water all over the desk
fervent epoch
And that was using capacitance?
errant pumice
yeah using a touch sensor on the touch pin of esp32 in "setup mode" so it spams its output
theres alot of settings you can mess with but it definetly changes when water was going in
fervent epoch
Oh yeah I could definitely see it change as it was going in, my only concern was the lack of change from empty to full. Your first reading was 540 and so was your last reading
Understanding it wasn't the most scientific of tests tho π
errant pumice
it changes slightly when i get got closer to the metal too. toching changes it alot but even getting close changes it slightly
you might need to play with sensitivity and average results to do a more scientiffic test
if nothing else i proved you can rig it up with an esp32 very quickly π
fervent epoch
Yeah, I don't mind buying a few sensors to test it out. I'll find use cases for them eventually
I've been poking around on M5Stack
I found this for a scale
https://shop.m5stack.com/products/mini-scales-unit-hx711
errant pumice
yeah i have one of the m5 atom echos laying around. its pretty good stuff. my test just now was just a dev board i had on the desk
the capacitive sensor would definetly detect when the dog was drinking though. if you know the dogs average drinking rate then you could use that to estimate too
fervent epoch
Hmmm that could be a fun statistic.
I could also hook up both and maybe I could use a combination of data
errant pumice
maybe you could use a flood sensor in reverse too
this has been a fun little brainsotrming session in any case π
fervent epoch
That would require something in the bowl
fervent epoch
this has been a fun little brainsotrming session in any case π
Oh definitely. I just randomly thought about it this morning as I saw his bowl was empty
errant pumice
you could go camera and rig it to AI too i guess
thats always a solution to problems these days
fervent epoch
The issue would be seeing the water
which is my issue rn π
I did think about making my own bowl briefly
3D printing some demo/POC and then finally making the finished product out of wood
That way I could use a water level sensor
errant pumice
hope you got some ideas now anyway. good luck with it. be sure to post it when it works
fervent epoch
Appreciate it! Will do