Quantity   Component name
2 × Raspberry Pi 3 Software PLC and Grafana+NodRED
5 × Arduino Uno / Mega 2650 Remote I/Os (cat feeder, door alarm, ...)
1 × 1kg Load Cell and HX711 A/D converter Measures how much cat food is left in the bowl
22 × RCS 1000 N (Brennenstuhl) 433,92 MHz wireless control socket Cheap but reliable Actor for mains powered devices
2 × Generic 433MHz sender To transmitt to the wireless controled socket
1 × A whole bunch of other electronic parts
1 × Some 3D printed cases
3 × DS18B20 I2C Digital Temperature Sensor Measures temperature in the fridge, warm, cold water supply and utility cabinet
2 × DHT11/DHT22 Humidity and Temperature Sensor Measures room conditions
3 × BH1750 I2C Digital Light Sensor Measures room luminosity
2 × HC-SR501 PIR Infrared Motion Sensor Motion sensor
1 × LJ12 A3-4-Z/BX, inductive proximity switch Senses door lock state (locked/unlocked)
1 × Generic NO Reed Switch Senses door state (closed/open)
1 × Nema 23 Stepper 2.8A 1.26Nm Drives the auger of the cat feeder
1 × TMC2208 Stepstick Stepper Motor Driver For the stepper in the cat feeder (leftover from a 3D-printer bulid)