I am not sure this is the right board for this topic...
The documentation links on the boards with 3 relays BB-RELAY3-12V (https://www.olimex.com/Products/Breadboarding/Relays/BB-RELAY3-12V/) and BB-RELAY3-5V (https://www.olimex.com/Products/Breadboarding/Relays/BB-RELAY3-5V/) pages are broken, so I have some questions.
Is it ok to drive these relays with signals from GPIO at 3.3 V?
What should be connected to VCC (3.3 V or 12 V and 5 V respectively)?
What should be connected to GND and RGND?
Are these products going to be open source hardware?
Thanks!!
Seems like BB-RELAY3-5V is the more suitable board for you. About the questions:
These can't be powered from 3.3V. As the names suggest one has 12V relay, the other has 5V relay. The 12V relay requires 12V DC power, and the 5V relay requires 5V DC power. This power is applied to the VCC pin.
Get the BB-RELAY3-5V it can be driven by 3.3V signal due to the optocouplers.
The BB-RELAY3-12V requires higher voltage to be driven. Around 9V DC.
These boards BB-RELAY3 require two power supplies (which means two + and two -), hence why two grounds - one for the relays and one for the signal driving them. If you power the BB-RELAY3-5V you connect 5V DC to VCC and the ground of that supply to RGND (I guess it is short from relay GND). And if you are controlling the relay with 3.3V signal you connect the ground of the 3.3V level board to the GND pin.
These aren't Olimex designs, we re-sell these boards. No way to open the design.
Very clear, thanks!