Hi again blynkers, finally the parts for the ac detection have turned up from China so I have now hardwired a single channel of this 2 way switching circuit up on my bench actually using 240v mains and a lamp and physical 2 way switch…
DISCLAIMER - PLEASE BE AWARE IF ANYONE ATTEMPTS THIS PROJECT YOU MUST HAVE A THOROUGH UNDERSTANDING OF ELECTRICAL ENGINEERING AND THE VOLTAGES YOU ARE USING ARE POTENTIALLY LETHAL - YOU HAVE BEEN WARNED.
Ok here are a few pics of this setup on the bench if the on state and off state. You can see in the on state that the LED on the AC to 5 logic board is on indicating data is being fed back to pin3 on the Arduino.
Here is a pic in the off state
Here is a pic of the ‘manual’ two physical switch where you can still turn the light on and off, and because of the AC feedback provided by the 240v to 5v logic board the widget also gets updated on the app so all the buttons will be kept in sync.
Clearly I have used a 4 ch relay board and 8ch 240v to 5 logic board, using a single channel and button widget for the demo here. The test rig is wired exactly as per the diagram above this post.
Next stage is I am building the whole thing into a box with 16 channels(using a Mega2560 for this). I will upload pics when that is complete. @Jamin and @speed57
I will post the code once I tidy it up.
here are the ebay links to some bits
240v to 5v logic board optoisolator
8ch relay board