Raspberry Pi Zero 2W

The Raspberry PI sits at the core of the design and the latest generation of the Supporting PC has been design so that you can solder a 90 degree din socket onto the I/O header and then plug it directly into the supporting PCB, which supplies the power to the Raspberry via the I/O header

The Custom PCB

The custom designed, surface mount PCB provides a wide range of additional sensor support support via digital I/O of the raspberry, 24bit ADC, Real Time Clock (RTC) and the ESP32-S3 micro that provides a lot of the functionality including controlling the power to the RaspberryPI.The PCB has been designed using the Open Source KiCAD and was laid out via FreeRouter which can be downloaded from Github. A PDF printout of the Schematic is available and the KiCAD version can be found in the CAD folder of the GIT repository. This is the 4th generation of the PCB and all of the components are SMD, except the edge connectors. You will find the Kicad Project and the resulting Geber files in the CAD folder of the GIT Respository

Any 12VDC Solar Regulator / charger

Any basic 12VDC solar panel / charging unit will do the job. I used a relatively cheap MPPR unit from Ebay, which had a range of built in protection and an LCD read out and a secondary load switch

A 12VDC Solar Panel

Any greater than 80W 12VDC solar panel will do the job. I used a relatively cheap 140W unit from Ebay, to give me plenty of capacity in the power and charging circuits.

A 12VDC Deep Cycle Battery

Any 12VDC Deep Cycle Battery will do the job. I used a relatively cheap 24AH sealed version, to give me additional storage capacity for the winter months, which have shorter days and typically overcast. You may be able to use a smaller capacity battery, if you increased amount of time that system is in standby mode (Raspberry and Touch Screen are powered down)

A 12VDC Water Value / Solenoid

Any 12VDC Water Value will do the job. I used a more expensive brass model with a 1/2 inch thread, because of the high water pressure that the header tank generates. If you don't have this issue, you could use one of the plastic models that are listed on Ebay

23RPM 12VDC Reversible Electric Motor & V Type Pulley

Any Geared ~23RPM 12VDC motor will be able to handle role of the motors that open the main and yard gate doors. I used these from AliExpress that also have 2 x built-in encoders that the system can use to detect a jammed or stopped door

5 x Inductive Proximity Sensor Switch PNP DC6V-36V

Early in the design, I was just using simple reed switches for the gate position sensors, but after burning out a couple of motors because the sensor had not worked correctly, I swapped these out for the Inductive Sensors instead. The inductive sensors are more expensive than reed switches, but once they are positioned correctly, they haven't missed a beat. The application will assume that PNP (Source not sink) are being used, but the software could be easily changed to use NPN sensors instead (I may make this a configurable value in the future).

I purchased these from Ebay and the P/N is: LJ12A3-4-Z/BY

1 x Single Float Value Switch (12VDC)

Any simple float value switch can be used to close the water value when filling the Water Tank. I used a stainless steel version from Ebay

20kg Load Cell

These 20Kg load cells will be used to monitor the weight of the feeder, to determine how much chicken food remains