Dirty cheap PCB will make your life MUCH easier.

The ultimate, cloud cat feeder

If you haven’t seen it before, this post is about the ultimate cloud cat feeder. See the product demo here.

PCB?

As I was putting the electronics together while testing it with Arduino on a breadboard, I went ahead and soldered it permanently, creating this disgusting spaghetti:

Disgusting electronics spaghetti Disgusting electronics spaghetti

One day, something there failed… and this event immediately gave me undoubtful hint that it’s time to design a PCB. I’ve downloaded Fritzing - a Grasshopper friendly, open-source program for designing circuits, boards, etc. Few hours later, I’ve created this:

Schematic of the ultimate cloud cat feeder Schematic of the ultimate cloud cat feeder

After ordering PCB and waiting… a while, I got this:

Board from the factory Board from the factory

Putting it together was a bliss. Given prices of a double-sided board these days - imported, with shipping = ~15$ for 3 pieces (!!!), I really wish I didn’t do it before. Here is the end result:

Assembled board Assembled board

Find the files here: TheUltimateCloudCatFeeder-PCB - GitHub repository

Bill Of Materials

Count Item Link
1 Stepper Driver - Pololu A4988 link
9 Jumper cap, 2.54mm link
4 JST Connector, 2.54mm, 3pin link
2 JST Connector, 2.54mm, 4pin link
2 JST Connector, 2.54mm, 5pin link
1 JST Connector, 2.54mm, 7pin link
1 DIP8 Socket, 2.54mm link
1 MH-ET LIVE ESP32 Development Board link
few Female&Male Pin Headers, 2.54mm link
1 Buzzer Module link
1 28BYJ-48 Stepper Motor + ULN2003 Driver link
~0.5m WS2812B RGB LED Strip, 144 pixels/m, 5V link
1 DC-DC Step Down Power Supply Module, 3A (9V->5V) link
1 200g Load Cell link
2 10kg Load Cell link
2 HX711
4 Ceramic Capacitor, 100nF, 6.3V
4 Electrolytic capacitors, for example 250uF
2 A3141 Hall Sensor
1 DS18B20 Temperature Sensor link
1 9V 2A Power Supply
4 22kΩ Resistor
1 47kΩ Resistor
1 4.7kΩ Resistor
2 51kΩ Resistor
1 470Ω Resistor
1 Calibration Weights link
1 100mm x 5mm Stainless Steel Ground Shaft Round Rod link
1 32DP 5mm 17T Motor Pinion Gear link

Note: the links are non-affiliate. Do not treat them as a recommended source of parts. Those are just to get details about the element, in case I forgot to include any details here.

What needs improvement?

Opsss, I forgot to add the temperature sensor to the board! Next version should for sure include it. Also, when programming the microcontroller, one need to press the button on the ESP32 board, which - taking into account how hard it is to disassemble the cat feeder - can be cumbersome.

What worked well?

So far, the cat feeder works with this electronics version for 3+ months, continuously. Fingers crossed for the future!

Other resources

You can find more details on the cat feeder (building progress, features, technical details) here - all posts with cat-feeder tag.


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