I need 24 channels to drive my irrigation system. As the opensprinkler expansion board is serialized using I2C, is it possible to directly connect to a raspberry or any other alternative board (+ provide 24V)?
My controller will be located in a network bay inside my garage (so always connected to the Internet for time, UPS for power).
What do you think ?
OpenSprinkler 3.0 uses I2C to communicate with expander; previous versions (2.3 and before, also including OSPi) use 74HC595 shift register to daisy chain expanders. You can choose either — if you are building your own custom circuit, 74HC595 is probably easier since it’s cheap and you can simply follow the pin connections of OSPi circuit (it uses just 4 GPIO pins to control up to 56 zones).
Thanks for your answer. I decided to design my own board based on an OrangePi and obviously your expertise and all you already developed! (I hate Raspberry since the day the SD card crashed and lost all data recorded on it; SD card are definitely not designed for permanent R/W operations).
I prefered to go to I2C (because I’m also curious about this serial bus, I’m from the generation of RX/TX/RTS/CTS … on RS232 :-).
Just another question: could you give me a starting point to understand how to develop the android app. I saw all the source on github but what are you using to design / compile / debug / test such apps ?
The application is just a web app that’s packaged for native using Cordova on Android/iOS. The code is basically all inside js/main.js. Debugging will be done by using the developer tools available in Chrome (works both locally and from Cordova via chrome://inspect).