Bcrich01
Posts: 3
Joined: Sun Dec 18, 2016 10:59 pm

Maker a timer based winch/actuator system

Tue Dec 20, 2016 12:09 am

Hi There,

I'm new to Pi programming and I have an idea for a project which involves raising and lowering a pot at certain times (for watering).

Essentially I'm wondering how easy it would be to program this to run indefinitely with a Pi and if anyone can advise me on what I would need to do it? I have found some code online for running actuators which looks like it would work but it's the timing step which is confusing me slightly?

I'm planning on doing it with either 1 (or 2) linear actuators or a DC geared motor as a winch.

Many thanks

Goraxium
Posts: 122
Joined: Tue Jan 26, 2016 1:42 pm

Re: Maker a timer based winch/actuator system

Tue Dec 20, 2016 1:24 pm

The timer is trivial. A simple cron job will even allow you to run it at set times of day.

You'll find plenty of Python / C examples online that could sort out the GPIO issues for you, which is the bulk of the work. Depending on how complex you make it, it could be a few lines of code or a few hundred...

My only question is why go through so much trouble when a solenoid would work just as effectively? You'd only need a single optocoupled relay (keeps the main power draw away from the Pi), the solenoid, hoses and adaptors to set the entire thing up... That way it'd be GPIO on = relay on = solenoid open = watering, and GPIO off = relay off = solenoid closed = no water.

Bcrich01
Posts: 3
Joined: Sun Dec 18, 2016 10:59 pm

Re: Maker a timer based winch/actuator system

Tue Dec 20, 2016 9:25 pm

Thanks for the swift reply!

Essentially, I need to drop the plant pots in a basket into the tank of water for the test, saves water this way and means I don't need to have two tanks if I want to use the same water. If this weren't the case, then definitely a solenoid would be the best way.

I also want to control the temperature of the water using a heating element, I'd guess this is easy enough as well?

Thanks for your help!

Bcrich01
Posts: 3
Joined: Sun Dec 18, 2016 10:59 pm

Re: Maker a timer based winch/actuator system

Tue Dec 20, 2016 11:33 pm

Using Crons, is there a way to lower the basket for a period of time, then raise it for a longer period and repeat?

I'd guess I'd need to have it time to run the program, then detect its position and either wait or run the program in reverse again?

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