The simulation circuit

A project log for MQTT hack for OpenSprinkler OSPi

At the beginning of 2024 the opensprinkler firmware cannot (yet) subscribe to MQTT topics. Can I make a hack to solve this?

mabe42MaBe42 03/03/2024 at 08:300 Comments

The current version of the OSPi hardware can be found at I don't need the analog inputs. So my simulation circuit is just a 74HC595 connected to the raspi as in the schematic (however, I powered it from the 3V3 rail) and LEDs at some of the output channels instead of the triacs.

Running the "Run Once Program" shows that everything works fine.

For the sensor inputs I provided 10k pull-up resistors to be on the safe side.

I assigned them to soil moisture sensors and when I connected an input to ground it was correctly recognized as wet soil which does not need irrigation. (The irrigation program was not executed.)