I have designed a custom board to use with Raspberry Pi and common 8 Relay Boards.
The design is based on the OSPi board.
Is uses an 74HC595 shift register.
It can be expanded using the same board.
The Pi is connected with the shift register with Data, Clock, Latch and OE.
The shift register is then connected with the common 8 Relay Board.
I attach some pictures of the PCB for anyone to check.
I also attach the .brd file for anyone to check/altern/use.
The problem at first was that I had to change the negative logic to positive logic because that 8 relay board I had laying around. I used this link.
Then I had another problem that is almost solved but I would apreciate any help because I am at dead end.
At first tests, when I connect anything to a power outlet or open a light in the house, the relays go like crazy. After some research, I added come capacitors to the 5v power jack that powers the relay board.
The problem is almost solved.
But today I noticed that for some reason, is I touch my macbook power jack to my iMac’s keyboard, the relays again go like crazy.
I think that the problem ocurres if I have at least on zone to run.