@Mouthpear I do believe in KISS, and the limit switches win...below is a quick drawing of tank track idea...the green boxes represent the limit switches (on the inside of door) the single wheel at the top is to keep the door from tilting, solid blue wheel would be drive wheel, orange circles represent "rollers" (help keep contact, and movement fluid)
View attachment 2369839
I like that. Looks to be a good plan. Again I love the tank track idea.
I have seen the L298N motor drive controllers... I thought the Rpi was capable of PWM already onboard... So, you say motor shield...others say relay board...
Yes, just like the Arduino, the RPi can be set up to run a motor and maybe two, but it is not recommended. Plus there will be a bunch of wiring needed and figured out, plus that wire will be needed adaptation from tiny pin header jumper wires to larger gauge motor wires.. With a shield only wires need to be run are the separate power source (POE) once and from there two wires to each motor.
Motor Shield vs Relay Board.
Both have their pros and cons. I will only talk about three 1 handling of different current types (AC vs DC) and Voltage. Which is really the thing of most concern. 2 And another tiny point. 3 Programing
Relay can handle and used to control the many combinations of situations. Like using a 12VDC relay to operate an AC desk lamp. Some motor controller can do that too but in your case you really don't need that since your application will not require a large motor.
The tiny thing is actually a big deal. With a relay or even a relay board you will have to power up each relay and wire it up. Then you have to wire motor power and motor on the NO, NC and COM of the relay. For each relay. A Motor Controller or shield is power in (two wire) and motor connection (two wire). No need to wire up 4 different motors to their own set of relays. 1 Pos 1 Neg in and 4 motors out. The modules I have can do 4 dc motors and two servos at the same time.
PROGRAMMING geez LOL.
make sure both relays are off
turn one on make sure the other one is off (no speed control)
turn that one off make sure they are both off
turn the other on on ..................
You get the point
turn motor on forward (with Speed Control)
motor stop
turn motor on reverse (with Speed Control)
motor stop
It's almost that easy.
Your food feeder/dispenser looks awesome...I would like to know more... I can see fill at one end, dispenses at other, do you have it dropping the feed into a bowl?
The water cooling mister idea also sounds like a COOL idea... as it does get very hot down here. I would like to hear more about it...
Thank you. Yes the drop end will be a short PVC pipe that becomes a troth. The troth will sit on a hinged platform. There will be a
weight scale that will take measurements before the feeder turns on. This is to regulate the time the motor is on and dispensing food. I want it near empty so that the birds will eat what they spill first. I also don't want rats to come at night and take advantage, so there a cover that shuts also. I will post pix on google drive so if you want to see the progress, that's where it will be.
The misting system is very basic. You can buy a deck or patio mist system and use a servo valve to open and regulate how much mist to put out. Use your RPi to get temp and humidity. If you don't want to spend the money on a Servo Valve the just get a cheaper Solenoid Valve and set the flow with a regular ball valve. But the commercial mist systems come with small values for that too. So a Solenoid Valve should do fine.