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There is no jVcc on this board.

This relay is designed to operate on 5V. Most commonly this will come from the Uno's 5v pin.

If you want to externally power the relay itself then make sure to connect the +5 goes to the Vcc on the relay board and the - lead to the GND.

Uno's GND also needs to be connected to the GND on the relay so the Digital outputs from the Uno will properly control the IN1 and IN2 inputs to the relay board.

The Uno has multiple GND connections so it makes the most sense to connect the - to one of them then another to the relay.

Note that the Uno's 9V Vcc external power comes in through the barrel connector on the Uno itself. The Uno will pass power through its internal regulator to provide 5v at the appropriate connection.

If you are switching external devices that run on 120V it would be on the screw-terminal side of the board only.

Note that this particular relay is ACTIVE-LOW which means that as you initialize the output pins you should first set them HIGH so setting the pinMode will not default to LOW which would trigger the relay.

In the setup() section, using pins D5 and D6 as an example:

digitalWrite(5,HIGH); pinMode(5,OUTPUT);
digitalWrite(6,HIGH); pinmode(6,OUTPUT);

This relay is designed to operate on 5V.

Most commonly this will come from the Uno's 5v pin.

If you want to externally power the relay itself then make sure to connect the +5 to the Vcc on the relay board and the - lead to the GND on the relay board.

Uno's GND must also be connected to the GND on the relay so the Digital outputs from the Uno will properly control the IN1 and IN2 inputs to the relay board.

The Uno has multiple GND connections so it makes the most sense to connect the - to one of them then another to the relay.

Note that the Uno's 9V Vcc external power comes in through the barrel connector on the Uno itself. The Uno will pass power through its internal regulator to provide 5v at the appropriate connection.

If you are switching external devices that run on 120V it would be on the screw-terminal side of the board only.

To prevent accidental activation of the relays, note that this particular board is ACTIVE-LOW which means that as you initialize the output pins you should first set them HIGH so setting the pinMode will not default to LOW which would trigger the relay.

In the setup() section, using pins D5 and D6 as an example:

digitalWrite(5,HIGH); pinMode(5,OUTPUT);
digitalWrite(6,HIGH); pinmode(6,OUTPUT);

This relay is designed to operate on 5V from the Uno's 5v pin. The 5v goes to the Vcc on the relay board. And GND also comes from the Uno. Obviously, the IN1 and IN2 come from D (Digital) output pins on the Uno.

Your 9-12V external power (The Uno's Vcc) should come in through the barrel connector on the Uno itself.

If you are switching external devices that run on 120V, for example, it would be on the screw-terminal side of the board only.

Note that this particular relay is ACTIVE-LOW which means that as you initialize the output pins you should first set them HIGH so setting the pinMode will not default to LOW which would trigger the relay.

In the setup() section, using pins D5 and D6 as an example:

digitalWrite(5,HIGH); pinMode(5,OUTPUT);
digitalWrite(6,HIGH); pinmode(6,OUTPUT);

There is no jVcc on this board.

This relay is designed to operate on 5V. Most commonly this will come from the Uno's 5v pin.

If you want to externally power the relay itself then make sure to connect the +5 goes to the Vcc on the relay board and the - lead to the GND.

Uno's GND also needs to be connected to the GND on the relay so the Digital outputs from the Uno will properly control the IN1 and IN2 inputs to the relay board.

The Uno has multiple GND connections so it makes the most sense to connect the - to one of them then another to the relay.

Note that the Uno's 9V Vcc external power comes in through the barrel connector on the Uno itself. The Uno will pass power through its internal regulator to provide 5v at the appropriate connection.

If you are switching external devices that run on 120V it would be on the screw-terminal side of the board only.

Note that this particular relay is ACTIVE-LOW which means that as you initialize the output pins you should first set them HIGH so setting the pinMode will not default to LOW which would trigger the relay.

In the setup() section, using pins D5 and D6 as an example:

digitalWrite(5,HIGH); pinMode(5,OUTPUT);
digitalWrite(6,HIGH); pinmode(6,OUTPUT);

This relay is designed to operate on 5V from the Uno's 5v pin. The 5v goes to the Vcc on the relay board. And GND also comes from the Uno. Obviously, the IN1 and IN2 come from D (Digital) output pins on the Uno.

Your 9-12V external power (The Uno's Vcc) should come in through the barrel connector on the Uno itself.

If you are switching external devices that run on 120V, for example, it would be on the screw-terminal side of the board only.

Note that this particular relay is ACTIVE-LOW which means that as you initialize the output pins you should first set them HIGH like so:

In the setup() section, using pins D5 and D6 as an example:

digitalWrite(D5,HIGH); pinMode(5,OUTPUT);
digitalWrite(D6,HIGH); pinmode(6,OUTPUT);

This relay is designed to operate on 5V from the Uno's 5v pin. The 5v goes to the Vcc on the relay board. And GND also comes from the Uno. Obviously, the IN1 and IN2 come from D (Digital) output pins on the Uno.

Your 9-12V external power (The Uno's Vcc) should come in through the barrel connector on the Uno itself.

If you are switching external devices that run on 120V, for example, it would be on the screw-terminal side of the board only.

Note that this particular relay is ACTIVE-LOW which means that as you initialize the output pins you should first set them HIGH so setting the pinMode will not default to LOW which would trigger the relay.

In the setup() section, using pins D5 and D6 as an example:

digitalWrite(5,HIGH); pinMode(5,OUTPUT);
digitalWrite(6,HIGH); pinmode(6,OUTPUT);