Hello fellow Arduino'ers,
I have been working on my home automation system for some time now and have tried to develop an entire home automation system from scratch. I know it might not have been the correct way to go but I wanted to go all-in on my own system.
I have an Arduino mega that is the systems controller. This receives all push button inputs (27 of them).
At first I used the INPUT_PULLUP functionality of the arduino to connect them. I have read info on reducing the pullup value to reduce EMI susceptibility so I moved from INPUT_PULLUP to regular INPUT and added in 4.7K resistors to my pin inputs.
All of the push buttons are connected via cat5e twisted pair cable (these can run up to 10-15m [30-50ft] long)
The arduino mega also controls 4 relay boards with 8 relays each. so 32 relays in total. For each group of lights I have 2 relays. 1 to switch "L1" and 1 to switch "N". I also have 2 rollershutters that are controlled by 3 relays each.
2 biggest issues:
Issue 1: random turning on of lights. I'm suspecting the twisted pair cables to be acting like antennas and triggering the arduino to switch the relays. This happens at random intervals. By adding the lower pullup resistor this seems to have already decreased a lot.
Issue 2: basically the same issue as issue 1 but this time I know what causes it. Whenever I switch my rollershutters they do what they are supposed to do. But the problem is when:
-If I stop the rollershutters programatically before it reaches its limit there is no issue.
-If the rollershutters are stopped due to hitting their limits this causes a burst of EMI and randomly switches on/off one of my lights.
What I've tried :
- smaller pullup resistors
- moved the relay board that controls the rollershutters away from the arduino
This link gives some extra advice but not all of it is possible to apply.
On top of that I don't really know what the MOV's do and how I would have to hook them up.
Any advice would be greatly appreciated as this is my actual home and having random lights turn on and off isn't making the misses happy