Hardware Reference
In-Depth Information
Hardware configuration
Now let's see how to connect the different components of the project. As with the other
chapters of the topic, you will need to have the Ethernet shield plugged into the Arduino
board. You will also need to connect an Ethernet cable between the Ethernet shield and
your router.
Then, you need to connect the relay module. The relay module has three input pins:
VCC
,
GND
, and a signal pin usually called
SIG
. You need to connect the VCC pin to Arduino 5
V, GND to Arduino GND, and finally the signal pin to Arduino pin number 7, which is a
digital pin. The following image shows the system at this point:
Then, you need to connect the power cables to the relay module. A relay module basically
has three output pins:
COM
(for the common pin),
NC
(for the normally closed pin), and
NO
(for the normally open pin).
What we want is to have the
COM
pin of the relay connected to one wire of the power
plug,
NC
not connected, and
NO
connected to one other wire of the power plug. The fol-
lowing image summarizes the connections at this stage:
