Solar powered watering system


I’m new to photon and any help is greatly appreciated!

I want to build a relatively simple system that will allow me to water my vegetable garden using the photon and photon relay shield. I have the thing up and running and it works well but it drains my battery incredibly fast!

Does anyone have any advice?

I know there’s a battery shield and I could include a solar panel. but that shield seems to power a 3.7 volt battery while the relay shield requires a 9-20v power source. Is it possible to set up my own solar charging station without the shield? any advice on how to do this?


What is the relay switching? Could you tap into that for power?

I would suggest you do a separate 12v solar power system.

Can you gupive us a breakdown on what’s hooked up where and how and how often do you plan to water?

Here’s what I would do. Not use solar shield or power shield but get an off the shelve (il look around) 12v solar system that can power a big battery to have power to spare a few days of clouds. The reason I am suggesting this is because coils are not power efficient, specially those in solenoids or water pumps.

You then regulate that power with a good DC regulator and power the photon from there along with solenoids and such.

After that you can start working on improving your power efficiencies like not to talk or turn on wifi radio when not required and look for solenoids that only consume power in transition and not the whole time the valve opens.

If you are not powering pumps, this seems like a more then adequate solution. Be careful to use good capacitors or a good dc/dc power supply before powering the photon.

This might work (or might be an overkill but you get the idea):

Thanks for the response. Here’s the setup:

One photon seated in the particle relay shield. there are 4 relays on that shield. Three of them control separate 12V solenoids.

That’s it, pretty simple.

i like the idea of the 12V solar system. that seems like it would work well. i’m new to electronics (and enjoying it a lot). could you make any recommendations on this and a DC regulator? i’ve never worked with a regulator, how hard are they to set up?

another option might be to have an AC->DC power adapter and run a cord from the house. any advice on that…it seems like it might be straightforward.

I know this is all a little vague, so i appreciate all your help that much more!

Hi @Rich1,

Try assembling what the link I put is showing you how. That will be enough to power the shield and everything else.

You do need to get 5VDC to the Photon… this is a good solution. It has enough amps to drive normal solenoid:

This is a good DC to DC power supply or converter :smile:

I assembled my take on a solar watering system a couple weeks ago. Haven’t tested it yet because it’s been a cloudy summer so far in Texas. But instead of relays, I’m using an H bridge to divert power to either a 12V DC water pump or the battery shield from Particle. It should charge most of they day, occasionally watering the plants (based on a soil moisture input), and the battery will keep it alive while it sleeps overnight.

Can you elaborate on this a little bit?

Motor drivers take an input voltage and route it to two outputs. You can then use enable voltages to choose whether or not the input gets to a certain output. They’re designed so you can put a voltage in, and attach it to a motor as a positive or negative voltage, so the motor can run backwards or forwards. I’m not using a traditional motor, but the concept is the same: I want my 12V to go to either the pump or the battery charge
You can read all about it on my post

Awesome!! Thanks for the info!