jdom1984
Posts: 1
Joined: Tue Nov 13, 2018 8:29 am

Automated Grow Environment

Tue Nov 13, 2018 8:44 am

Hi there I love growing my own herbs and vegetables and find the idea of a contained and controller environment fascinating.

I have a very small grow box which I wanted to control the speed of the intake and outtake fans and also set up a little 5v heater to switch on if the temp goes below a certain point. I bought a raspberry PI zero for the job and try to maintain a more constant temperature by controlling things via a temperature sensor I have purchased.

I am totally noob and I guess I thought there would be more easily available instructions, I worked out I probably need to use PWM to control my small 12v fans and a relay switch to control the 5v heating element. I bought some transistors and have some diodes, I have done basic soldering and electronics.

I have seen there are pre fabricated boards online that seem to be pre built with a micro controller that seems to do what I want anyway. I wonder is it really worth going through all this to get the PI to work? Maybe if its complex I could get one of these to do the job until I get my head around it? I assumed it was not too complex to set up a PWM and a heater with a thermometer sensor on my PI.

This is the thing I was looking at that might control my fans but it appears I might have to get different fans that are 4 pin instead of 2 pin as that gives them the PWM function. They are made for computer cases.

https://www.ebay.co.uk/itm/12V-PWM-PC-C ... :rk:7:pf:0

This one specifically mentions you do not need PWM fans for it to work but it is much more expensive:

https://www.ebay.co.uk/itm/DC-12V-24V-2 ... 1642255499


The obvious reasons I wanted a PI instead is the added functionality, wifi access, camera, music. I can get it to do anything and have super healthy tomatoes all year round and even keep an eye on them from anywhere in the world! But it's the most simple jobs I need the most, the temperature wildly changes at the moment and this is hurting my plants as it is cold here in the UK.

If anyone has a link to two simple diagrams or instructions with the script for doing simple PWM for these fans and then I guess I need a relay circuit for the 5v heating element I bought? Or I can switch that out for 12v so everything is 12v it might make things easier and have less wires going to the box.

Any guidance or links or advice would be very much appreciated. I have tried to look into it but found it a bit more complex and overwhelming that I thought.

Regards,
Dominic.

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