So I’ve had my SprinklerPi for a while, and most of the time it’s great. But I have an issue where maybe 1 in 10 activations the pi just hard locks the moment a valve is activated. I’ve tried different software (interval, demo etc), 2 different pi’s, pi firmware is up to date etc, but all seem to have the same problem. Seems to happen more often when multiple valves are activated at once (Some of my programs require 3 valves running together), but I’ve had it happen on single valves as well. My power supply is a reasonably strong 24v one that has run all these valves together without a problem, so I’m fairly sure it’s not the issue.
Is there anything I can look at on the Sprinkler Pi as it seems to be the single common point?
Sounds like your 24 VAC power supply can’t output enough power for the 3 valves and Pi. Ray suggests at least 500 mA. What does your supply say it can do? It may be that you need more than 500 mA.
Here’s a simple test: unplug the 3-wire cable and instead power the Pi with an AC to USB mini adapter that can supply at least 700 mA. If the lock ups go away then you’ll need to keep powering the Pi with it’s own AC to mini USB adapter or get a bigger 24 VAC power supply.
As KanyonKris mentioned, you can unplug the 3-wire cable (which provides +5V to RPi), and power RPi with a USB cable. The 8-pin cable has a ground wired, so as long as you leave the 8-pin in, the ground is shared.