This relay board has 8 channels. Is controlled with an MCP23008 I2C controller and a ULN2803 Darlington array.
It can be controled on two dirrefent ways:
– over I2C
– over ULN2803
It is controlled over I2C, it supports 1.8, 2.7, 3.3, or 5VDC systems. Also, in the case that You wish to drive the relays with the ULN2803, you can connect the ground on the G pin, and the relays can be controlled by providing a positive signal, in a range from 1.8 to 5.5VDC, on a different header.
The board has its 120/220VAC power supply.