I have purchased a 12v 8 relay board from Jaycar (cat 4418), and am trying to connect it to my Arduino Mega .
Connections are: PIn 13 on Arduino Board (AB) to IN6 on Solenoid board (SB), AB Grnd to SB Grnd, SB VCC to +12vDC, adjacent Grnd pin to -12vDC.
I have tried connecting the Grnd on the AB to the Grnd on the SB, with no luck.
When the 12v is connected to the SB the Red Power LED lights up, but no other lights come on as they should if the relays were triggering.
There is 1 pin on the SB that I am not sure about, labelled "Com", and this appears to be where the JD-VCC pin is on other SB's.
Any ideas gratefully received.
Hello mikemakit
Post your sketch, well formated, with comments and in so called code tags "</>" and a none-Fritzing schematic to see how we can help.
What is that? relay boards only use a positive and a GND; Please post a linke to the board that you bought.
"Com" is the common pin of the relay "output"; the other two related pins are usually labeled NC (stands for normally closed) and NO (normally open).
That relay board is a bit unusual for an opto-coupled board. Unfortunately the seller does not have a schematic or good wiring instructions. The only reference I can find seems to show the input is active HIGH, and needs the arduino GND connection.
For testing, I would remove the 12V power supply completely, then with the jumper removed determine which of the GND and COM pins need to be connected to the arduino for the indicator LEDs near the opto-couplers (hopefully this boards has them) to light up.
Hi Sterretje,
Sorry, what I meant was that the -12v lead (which is actually a "Ground" lead) is attached to the ground pin on the relay board .
The "com" pin is one of the "inlet" pins, opposite to the Solenoid outputs.
The solenoid is a 12v 8 channel relay board from Jaycar (in Australia) Cat XC4418. If I can work out how to attach a file to this document, I will attach a picture next time
Cheers
mikemakit