Andyroo
Posts: 2827
Joined: Sat Jun 16, 2018 12:49 am
Location: Lincs U.K.

Re: catPooPee

Wed May 01, 2019 2:17 am

No Bluetooth ones other than the one the MagPi covered at https://ideas.redpepper.land/has-anyone ... da3e0e47b9

There is this paper https://3pl46c46ctx02p7rzdsvsg21-wpengi ... _FINAL.pdf but I’m not sure how much is now and how much is to come.

RF tags though range from the NHS tracking beds, the RAF tracking cockpit cases and M&S tracking ladies dresses and food trays.

Identec had a low range RF-ID solution of their Rev 1 reader (about 15cm range) and TV4 tags (25 gram weight) but these may not be cheap.

The NFC Group had both vehicle and pallet location but it’s a turn key solution with interface costs on top.
Need Pi spray - these things are breeding in my house...

monkeyfork
Posts: 58
Joined: Tue Oct 29, 2013 10:14 am
Location: orlando

Re: catPooPee

Wed May 01, 2019 2:58 pm

Andyroo, the paper by Martin Woolley is best I've seen so far. Oddly sanitized of contact info but see the interWebs are littered with his videos. Now to see if this guy is правда or MoPoo.

curious_cat_behavior
this is Piffy-the-cat about to make a poo and/or pee event. Many times she will look into the motion video cam above so as to reinforce my belief that she is a shape-shifting extraterrestrial rathar than an actual cat. My other lab assistant _NEVER_ looks skyward, quite odd.

Image

integration on 2nd weighting platform has begun to connect a Teensy3.2 to rpi-zero-W. (before was arduino UNO to old rpi-B). Teensy was selected to have processing bandwidth (and DSP) to have growth potential to use audio to qualify if tray event is a pee or a poo (comedy potential of that feature is ginormous)

Andyroo
Posts: 2827
Joined: Sat Jun 16, 2018 12:49 am
Location: Lincs U.K.

Re: catPooPee

Wed May 01, 2019 5:25 pm

Glad you find that interesting. The paper is available from https://www.bluetooth.com/bluetooth-res ... ypes=paper

Very pretty cat :) for an alien.
Need Pi spray - these things are breeding in my house...

monkeyfork
Posts: 58
Joined: Tue Oct 29, 2013 10:14 am
Location: orlando

Re: catPooPee

Mon May 06, 2019 6:08 pm

weight measuring problems

I'm presently taking closer look at the weight measuring system as the 2nd weighing platform is being fabricated. I have decided that drift of load cells by keeping them constantly loaded (lightly) is probably not a problem. long term drift of output of load cells (with static load) still seems significant to me (on the order of < 10grams) but I figured I could get a good zero from streaming weight data just before a cat PooPee event to measure the delta of the event. However, I'm still running into a problem that I thought I had whipped. I've measured more occurrences of an event delta being negative when it's obvious by motion video that cat left a prodigious-poo. So, I will return to methodlogy that seemed to help that situation before, more stiffening of the weighing platform. The idea being that sag of platform between load cells changes contact geometry enough that load cells are not really orthogonal to floor so are measuring only partial load on sensitive axis. Seeing-good-in-bad... this is good time to make another pass at documenting the wiring of arduino-to-load cells which in turn attaches to raspberry pi (serial-usb).

Andyroo
Posts: 2827
Joined: Sat Jun 16, 2018 12:49 am
Location: Lincs U.K.

Re: catPooPee

Thu May 16, 2019 4:26 pm

How are things going?

I've just come across this (while looking for something totally different) indoor locator beacon set and thought of you :lol: That one is based on 915MHz but they do a 433MHz version.

Drawback is the $400 starter set!
Need Pi spray - these things are breeding in my house...

PhatFil
Posts: 1181
Joined: Thu Apr 13, 2017 3:55 pm
Location: Oxford UK

Re: catPooPee

Fri May 17, 2019 6:55 pm

rather than weighing the mass of the litter tray, is it feasible to weigh the cat on the way in and on the way out by perhaps sitting a tubular entrance on a set of scales that the cat needs to pass through in and out. the difference between the two mass measurements will be the mass of whatever was deposited.
use a small tunnel and delay opening its exit to contain the cat statically or a second or two while a good measurement can be taken on the way in and on the way out or take multiple readings and take a modal or mean average measurement to iron over any blips..

monkeyfork
Posts: 58
Joined: Tue Oct 29, 2013 10:14 am
Location: orlando

Re: catPooPee

Sun May 19, 2019 12:29 pm

Andyroo... very interesting link you supplied because it appears to be very close to something I've proposed (for Robot navigation). I'll be looking into that one closely. What I'd proposed was use the same ultrasonic burst for the purposes of measuring time-of-flight (much easier in the acoustic domain because of the long TOF's @ 1100fps rather than speed of light). I'm guessing that they have the RF link for a ZTT (zero time trigger). What I had proposed was to get really precise with time syncs with a local NTP time server, then _schedule_ acoustic bursts (not try to ZTT). Oh well, we'll see how they do with market penetration, good luck to them. Will be interesting to see how they combat the directivity of the ultrasonic transducers.

PhatFil... I'll keep your scheme in mind. Right now I don't want to confuse the tray entry paradigm quite yet. I'm not an expert in cat behavior (or cat patience). I sure don't want to raise the requirements of tray entry so much that they say... "wtf... ok, I'll just crap on the floor". However, I have been thinking about slowly restricting tray entry to just one of the tray narrow sides. I've now gotten some cheap-Chinese pet-chip readers that came with some of the ear-tags that Andyroo had mentioned. I'm hoping that if I put the ear-tag on a collar and restrict entry to one side that I might have a chance at medium reliability "who-is-in-the-box" determination.

As for me recently... I've been making a process for cleaning safflower seeds so I can extend the seed-as-litter life. I've fabricated a huge grain drying hopper that vertically tosses and tumbles safflower seeds after a wash cycle. Air blast for this contraption comes from a hugely noisy leaf blower. This process definitely needs some rpi-robots as it is way way too labor intensive and boring.

monkeyfork
Posts: 58
Joined: Tue Oct 29, 2013 10:14 am
Location: orlando

Re: catPooPee

Thu May 23, 2019 3:12 pm

while i'm thinking about it... Andyroo linked an interesting indoor positioning system in recent post. I'm looking at that for some indoor robot needs however it DOES CONCERN CATS. Originally, their default ultrasonic beacon freq is 31khz. Good choice (i think) for propagation maybe without too much directivity (this is not sonar ranging so omnidirectional is necessary). However, 31khz is well with cat hearing range and these things would be yaking all the time driving our poor furry lab assistants bonkers. (you do have furry lab assistants don't you). So, I'm throwing on the pile of things to do to get ultrasonic spectrum analyzer and do surveys to see what tech might be annoying my buds. (could explain strange cat behavior that I see everyday, ha).

monkeyfork
Posts: 58
Joined: Tue Oct 29, 2013 10:14 am
Location: orlando

Re: catPooPee

Sun Jun 02, 2019 4:05 pm

ok, it's official, the load cells (weight measurement sensor) are pissing me off. Something in the full contraption ( raspberry pi, three load cells + three differential amp with 24bit resolution) does NOT give repeatable measurements. All of the code being used is just cobbled together arduino and rpi code and nothing was looked at with my old old mission critical aviation eye. Now I'm going to back up and look at component parts and try to get good confidence in a single arduino + load cell (measuring weight of cat's water bowl) before returning to full system. Sorry for delay in the perfecting the ultimate open source raspberry-pi/arduino cat litter box, your patience will be rewarded (with happy cat poo).

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