Maximum Number of Zones

[HereComesTheRain]

Looking at your boards and after inspecting one of mine I think your good without an extra psu.

If I'm not mistaken your boards have a 1K resistor in series with the leds. That should be R3,R5,R7,R9....  with a value of 102, which means 10 + 2 zeroes, so 1000 Ohm or 1K.
So the real power consumption per channel is about 2mA. This is also what I just measured on my own boards.
The calculation then would be: 32 * 2mA = 64mA when all channels are on. That is of course no problem at all drawing that from the 5v rail of the Pi.

Good luck with connecting everything.

--Gerard

Uh-Oh!

Have not proceeded with attaching the irrigation valve wires and its independent power supply but I think I have a problem.

I have an ACP Back-UPS ES 350 in my irrigation enclosure.

The Pi power supply and the Relay Module(s) power supply is connected to the Battery Backup/Surge Protection side of the UPS.

I have a USB powered exhaust fan connected to the Surge Protection side of the UPS.

If I unplug and plug in the USB exhaust fan one or more of the RELAYS are triggered. Each time I unplug and plugin the exhaust fan more of the RELAYS are triggered.

Located below the irrigation enclosure I have a GFI within its own enclosure.  I brought power from the GFI enclosure, via wire nuts and not from the GFI, to a GFI within the irrigation enclosure.

For a test I plugged a jigsaw into the GFI outlet below the irrigation enclosure when I engaged the jigsaw all of the RELAYS were triggered.

It appears that fluctuations in current causes the RELAYS to trigger.

Any idea what is going on and how to prevent it?