RELAY

EC-R3576PC supports one relay output where ON corresponds to OUTPUT1
in the hardware schematic and COM corresponds to RELAY_COM1 the
hardware schematic.

Interface Diagram


schematic diagram


control

When GPIO3_D0_Output low level, OUTPUT1 will be disconnected with
RELAY_COM1 ; When RELAY_CTL1 output high level, OUTPUT1 will be
connected witch RELAY_COM1.

Since the lower layer Ext Yellow(L2) and relay are controlled by the
same GPIO, controlling Ext Yellow(L2) is controlling relay output

The control mode is as follows：

   echo 1 > /sys/class/leds/extuser/brightness //The lower monochrome led is on, the relay is worked
   echo 0 > /sys/class/leds/extuser/brightness //The lower monochrome led is off, the relay isn't worked

EC-R3576PC LED wiki