Hi Paolo,
My hardware arrived today finally so I am going to start working on this shortly. I was wondering if it would be possible to change it a little so that the Ultrasonic Sensor is run from the Raspberry Pi direct (which is running opensprinkler) and just use a single ESP2688 at the remote end. Given I am only doing a maximum of 12 zones from the raspberry pi for sprinkler operations (likely only 2-3 in the next couple of years), there should be sufficient pins left to physically hook everything up. Basically just trying to reduce the number of components required at the end of the day if possible.
I tried connecting to Arduino IDE 1.8.2 and have been having a few issues getting it to do anything, so I downloaded ESP8266 LuaLoader 0.91 and flashed the firmware and have been able to get it connected to my wifi and respond to commands straight away. I am incredibly new to this and learning as I go so any guidance you can provide on what I am doing wrong / what I might be missing for Arduino IDE to not be working?
What are your thoughts on connecting the sensor directly to the Pi, and if you think it will work, are you able to assist me with the code required and how to integrate it with the proposed system, including the code for the remote receiver (ESP8266) that is responsible for turning the remote pump on and off.
Cheers,
Raoul