I'm having some difficult problems with getting a 16 channel relayboard running on my Arduino UNO. So maybe someone could point me in the right direction.
Today i received my Elecfreaks 16 channel mini-relayboard (12volt), and i tried to hook it up to my Arduino. It is this relayboard:
As you can see, it has 3 rows of headerpins. The top row with the red headers are all connected together from lef to right. The middle row is used to connect the red ones with a shunt to the corresponding channel. This is only used, when i want to use the board without a MCU. They are switched on then, by the switch on the right. So this is not the problem, because i don't use this feature.
The bottom row is my problem. From left to right:
VCC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 GND
I connect my external 12 volt to the VCC and GND pins, and a second GND line to my Arduino GND. The other pins 1, 2, 3, etc etc are then connected to my Arduino pins 2, 3, 4, etc etc. But when i test it, with a modified Blink sketch. Nothing happens.
The relayboard works as far as i can see. All channels can be switched by hand, and if i connect the channels to a arduino pin, the relay responds. But only then. When the sketch has to do his job, the relay does nothing, where it normally would have to blink / switch on and off.
When i connect the VCC and GND of the relayboard, to my 5V and GND on my Arduino, the relays do switch on and off, but without a click. So it has not enough current to switch it on i guess. But the relayboard has to use 12 volt.
What am i doing wrong?
Thanks in advance