# Meowton Electronics 

# Requirements

* Rapsberry PI: Version 2 or higher (Pi zero and rapsberry pi 1 are probably too slow)
* Servo motor, see [Food dispenser](Meowton-food-dispenser)
* Two HX711 converters:
  * https://www.aliexpress.com/w/wholesale-hx711.html
  * https://www.sparkfun.com/products/13879

An overview (click to zoom):



[![](https://github.com/psy0rz/meowton/blob/rpi/3d/electronics/overview.jpg?raw=true)](https://github.com/psy0rz/meowton/blob/rpi/3d/electronics/overview.jpg?raw=true)

# Assembly

I recommend soldering everything, instead of using breadboards. (Those are less reliable)
## Rapsberry PI

Everything will be connected to the Raspberry PI (RPI).
For reference heres the pinout:

![](https://github.com/psy0rz/meowton/blob/rpi/3d/electronics/rpi%20pins.png)

I use a connector, but you can also solder directly to the RPI.

## HX711 board for food scale

Connect the HX711 to the food loadcell:

* Red wire: E+
* Black wire: E-
* White wire: A-
* Green wire: A+

Connect the HX711 to the Raspberry:

* GND to GND
* VCC to 3v3
* DT to RPI GPIO 23 
* SCK to RPI GPIO 24 

## Cat scale load cell

The 4 loadcells are connected in bridge mode, to one HX711:

![](https://github.com/psy0rz/meowton/blob/rpi/3d/electronics/loadcell%20bridge.jpg)

Connect the HX711 to the Raspberry:

* GND to GND
* VCC to 3v3
* DT to RPI GPIO 27 
* SCK to RPI GPIO 17 

## Servo motor pinout

The servo needs 5 volt and has one of the following pinouts:

![](img/servoconnect.jpg)

* Connect the signal pin to RPI GPIO 18