RP2350 W based sprinkler controller
There are WiFi controlled sprinklers out there, doubtful any open sourced for control. According to Google it is a popular DIY project, so why should they get all the fun.
Most people seem to be using 8 relay boards available on Amazon for under $10. That really is quite deal, but relays are overkill for a sprinkler system running at 24 VAC.
Most consumer units use run of the mill triacs. And you can get opto-isolated versions.
My first design would have attempted to just use the opto-isolated triac, sounds good, but between comments from others and claude reviews real power triacs had to be added. Luckily it all still fit into my proposed PCB layout (and enclosure I picked up). Just had to move the MOC30x2 to the bootom of the PCB along with snubber networks. (schematic and layout in gallery)
So I got the PCBs in, but still had to chose some components. Instead of building 8 channels, I used an old blank PCB and breadboarded up one channel. With that I verified the operation and started tuning the components. Discussions with Google AI and probing with a scope, the zero-cross opto-triacs behaved well and had no overshoot problems. Actually the overshoot for rnadom triacs was less than 20% so lots of headroom on voltage so a snubber was not needed, but the best values would be 4700pF and 47ohms. (jig in the gallery).
So now time to build up the board, where I am now. The 24VAC -> 5V power module will get added when the software testing is done. (box with power module picture in the gallery).
Using the RP2350 W will give me access via wifi and through my tunnel via cell phone so I can control sprinklers while walking around the yard.
