Hello,
I am working on a project that has multiple power supplies and an Arduino board.
here is a rough block diagram of it cold storage lock diagram.PDF (19.2 KB)
There are 3 big rooms and each has 4 floors. Each floor has some parameters that are controlled using relays by separate Arduino mega boards. Each controller has a separate 12V power supply.
In single room 3 Arduino connected to the 4th master controller using uart and ground. Also, 1 Arduino UNO is connected using MAX485 which has sensors connected to it.
NodeMCU connected using I2C to each master board for sending data to the server. All of these board grounds are connected to each other.
Nodemcu and Arduino Uno connected with UPS and others with direct supply due to heavy load.
At a normal start, everything works well but when the power supply cuts off and again comes back uno which has sensors connected sends the wrong values. its happens sometimes. Then Uno needs to reset manually.
I think it is because all grounds are connected together.
Please anyone have a solution to this? Also if I need to separate grounds how to do it?
Edit: nodemcu i2c connected to arduino mega insted of uno
Yes NodeMCU and UNO is alwase on because of UPS. Only Mega related circuitary is off. Its not a problem
My problem is when power back and Mega related circuitary is on then it sends wrong sensor values to mega. And after pressing reset button on uno it gives correct values.
It looks like a fairly complicated system. I'm not sure I (or anyone else) could help without seeing all the code for all the processors and a detailed schematic.
Sorry the diagram does not download. Is this in a commercial building with 3 phase power? Any idea of what voltages are involved in the 3 phase system(s)? What part of the world is it located? Can you post a more focused picture from further back. I think I see some problems in your photo. Also how much revamping are you planning on? What type of cabling is connecting things? What sensors are you using. Validate the UPS, many drop out a short time when power fails especially when it gets 'bouncy'. Good Luck!
