Raspberry coop

[jthornton]

Well it's like the pygmy that ate the elephant, one byte at a time...

In the Coop 1 I used a plug in screw terminal block for my connections. To control the motor I used a relay block with one relay for up and one relay for down. I have a wiring diagram somewhere, I'll need to find it.

I'll get some photos this weekend after I blow the dust off lol.

JT

 

[veedabowlu]

YES wiring diagrams, pictures (worth a thousand words)... would be great. I see reversing the polarity of the motor to change direction, but did not realize needing a relay for each way...etc...I do understand that there is always more than one way to do the same thing...

I did find this motor very similar to your suggested one...seem good?

 

[Tsheaby]

I thought @Tsheaby did an excellent job explaining how to build a chicken door...

JT

Thanks JT!

 

[jthornton]

I did find this motor very similar to your suggested one...seem good?

It looks exactly like the ones I use.

JT

 

[jthornton]

This is how I wire the motor for forward and reverse without the limit switches as I use them in my program. How this works is you energize one relay and the motor turns one direction, energize the other relay the motor turns the other direction. If both relays are off or on nothing happens so this makes a safe setup. The motor is connected up to the common on each relay and the normally closed is connected to 0vdc and the normally open contact to 12vdc. CR is the coil and in this example you could open and close a door with nothing but a single pole double throw switch and a couple of limit switches. It's great for testing the door part of your automation.


JT

 

[veedabowlu]

@jthornton That does make some sense... I guess I'm used to wiring up automotive relays only on the 12V (hot) side to run lights... horns etc...

I stumbled across this different way of controlling the motor & direction...that's why I was asking about breadboards, etc...

 

[jthornton]

Yes, there are more ways to drive a DC motor than corns on a cob. Using an IC is a fun experiment with tiny motors for sure.

JT

 

[veedabowlu]

Well, I haven't been here for a short while... I fell down the (rabbit) Pi hole with some possibilities. (very easy to do, by the way) Looking for ideas, finding a bunch of robot kits, remote control cars, robotic arms, AI, etc...
Waiting on some Rpi "starter"/experiment/tinker kits...and got to thinking... instead of one drive wheel (hoping for good grip) I have been think about a belt drive... what about a drive system like a tank track... instead of maybe getting a 1/4" of wheel contact, I could get 10" of "wheel" contact...depending on the tracks I use... and be able to support the door.

I'm also waiting on a similar motor that @jthornton recommended...

 

[jthornton]

You will have to keep us posted with your experiments.

JT

 

[Mouthpear]

I just don't understand how it would know where "zero" or start is...

There are a few ways that this is done but I will only cover the most common. When I say most, I mean the one that I personally have seen, used in person and research. AKA Youtube. LOL.

The use of a reset switch/sensor. It can be a limit switch or proximity sensor or laser (through beam or defused/bounceback). I would prefer a hard contact switch. Depending on the quality of sensor, they can be "thrown off" by how fast the motor speed is set at. It may react but at different distances and times. Basically the calibration needs to be checked often. Weather also can affect those sensors. A basic limit switch is best.

Whatever you choose can be set anywhere alone side door's path. Fully open end, fully closed end, or even anywhere in the middle. Best to be placed at either end. The key is that you know how far the distance is or how much travel it takes to get to either side. Which corresponds to how many rotations or window counts on that wheel. It get logged into a counter.

Lets say,,,
When the motor/door reaches the fully closed position, the limit switch is triggered and the counter is reset.

When it is time to open, the programing needs to be done so that the limit switch is checked to see if it is open or closed.

If closed (as it should be in this point) it starts to open the door and counting the windows starts.

Once it reaches the set amount of windows it stops.

At closing time all that is needed is to run the motor to close and once the limit switch is triggered it stops.

Limit switch open/closed should be tested every 10 min or so, after closing time, just in case of a power outage or something went wrong. It be a good idea to send you a text if the switch is not reading closed, during night time hours.

For testing and other reasons, the door open cycle should be to close the door and trigger the limit switch to reset the counter, then the door opens.

I hope I didn't overcomplicate it.