Hey all. Searched google and here and cannot find the exact answer.
My board is a 12v controller 8ch relay board. I connect the dc+ and dc- to a 12v battery and then put the jumper cables to the in1-in8 from digital pins 2-9
I don’t have a vcc so cannot use some of the diagrams I’ve seen. Please see attached photos of my setup
I am using the PS3BT code I have posted in another thread. I have added digitalWrite(2,HIGH) to send 5v down one of the pins which goes to in8 on the relay when I press the up button on my PS3 pad. Down button does 2,LOW to turn off the relay The arduino is doing it correctly but the relay doesn’t switch.
I haven’t put any wiring to the gnd on the arduino uno r3 board nor have I put 5v from the uno board anywhere
It does. Clear photos that tell very little.
Please upload a schematic. I suspect from your vague description that you have not connected 0V on the Arduino to the battery -ve.
So I am to connect the uno gnd to the gnd which is linked to the 12v battery gnd?
Yes.
How else is the circuit going to be completed? They are called circuits because the little electrons get home sick and like to circulate back to their home, in their power supply
(Please understand I am feeling silly and mean no offence, anyway, you are more likely to remember that way)
So I am to connect the uno gnd to the gnd which is linked to the 12v battery gnd?
Yes.
No, you need the Arduino GND connected to the 'relay board input' GND.
Now you are confused as LarryD is disagreeing with me. Unless I have misunderstood him we are saying the same in different ways. Connect 0V (ground) at the boards, not at the battery terminals. If Larry thinks I've misunderstood him I'm sure he'll be along soon enough to confuse you more