Local Deployment for SureFlap / SurePetCare Connect using only local MQTT Broker

Development
545

As promised, some pictures. sorry that it took some time, but I had to dismount the whole thing for this. First, see the hole I mounted on the bottom of the inside housing for the USB connector:

catflap-bottom_view_outside
catflap-bottom_view_outside1536×2048 326 KB

This USB connector is part of the step up converter pcb, so all I had to do is glue that PCB with hot-melt in the right position as shown below: (sorry it can be done much cleaner and I used quite too much hot melt :slight_smile:

catflap-bottom_mounted_pcb
catflap-bottom_mounted_pcb1536×2048 262 KB

From this PCB the two power wires are led though the left side to the top, where the battery compartment is mounted:
catflap-wiring_on-left-side
catflap-wiring_on-left-side1536×2048 350 KB

If you look at the battery compartment you will see the minus connector for the battery in front and the plus wire at the back. These connection points are soldered directly to the PCB using a metal pin.

catflap-top_connection_with_diode
catflap-top_connection_with_diode2048×1536 341 KB

Since you have to mount a diode from the battery to the PCB to avoid them being (over)charged all the time, I decided to cut the connection pin from the negative battery connection and bend it away because that was the easiest . There I soldered diode D1 between the battery pin and the cat flap PCB. From that same point on the PCB I soldered the other (D2) diode as well, that is connected to the blue minus wire to the step up converter. (see the red circle on the photo above) Notice the diode was fitted in a heat shrink tube to avoid short circuits.

See the schema below: (notice the diode direction. if you decide to cut the plus instead, you should mount diodes in reverse) D1 will protect the batteries from overloading, D2 will protect the batteries from discharging over the step up PCB when no USB power is applied.
catflap-Diagram_2

When you tune the power to be exactly 6v on the plus and minus on the Catflap PCB, the sensors will work correctly. Tuning is done with the small screw on the step up pcb. tune the pcb to 7v before mounting and fine tune it when mounted.

When the USB power fails, batteries will automatically take over. because of the slight power drop over diode D1, the batteries will power the PCB with just enough to function, but the low battery indicator will be activated. I found that quite useful, when my wife had by accident disconnected the USB charger :wink:

1 Like
546

This is really helpful, thnx s lot for sharing!!!

547

Today the sureflap cloud wasn’t working correctly, one more reason we need local :+(

548

Sure eventually provided the replacement catches, but didn’t put a stamp on the envelope, and it turns out replacing the springs is a super fiddly task.

I’ve bought a Pi5, 2 cameras and a servo motor. So I’m somewhat committed to building a working 3d printed catflap now. (Then of course I’ve got to build a cloud with a 2 nines uptime and constant code updates to break local hacks and make everybody’s life hard… )

Obviously it’ll need mains power rather than battery, but I that’s one fewer set of batteries to replace in the house…

549

Hi, just to be sure, I’ve a hub with firmware 233.364. Is that a game over? Thx

550

Hey @peterl,

Just wanted to say a big thanks to you and some others for your long efforts on this project from Australia.

I came across it wondering if there was a way to sniff the communication between my cat flat and the hub as I ’simply’ want to know which of my 2 cats came inside or went outside faster without some sort of camera training.

Currently it’s looking to be not super feasible for me while I look into this on holiday but I’m keen to keep an eye on this thread. Maybe SurePet will do better in the future (unlikely :stuck_out_tongue: ), but thank you none the less

Lint