I guess I should have been more clear, my apologies. For the project I am doing I plan on having this one power supply power the entire system. I’m trying to make a stand alone garden that plugs into the wall. So he supply would have to power all of my pumps, valves, and sensors as wells as my Photon. I know ill need a 5v linear regulator and now i know i wont need a 12V.
In regard to the board; I have had a feeling that i would eventually need to make the switch. I so far have been just testing everything individually before i start to put it all together. Do you think I should do my entire circuit on the soldered board or just the higher power things?
Now back to the original problem, for the heck of it I tried the above circuit as is and it worked from the jump without the jumper connected to the resistor. When i connected the photon while it was running the valve failed to open and close. So essentially the problem i was having that made me want to come here for support was fixed by the solution you suggested and now that same solution doesn’t work and the original problem works. Any thoughts on why this is acting so strange?