How to Use a Relay Module in an Arduino Project

How to Use a Relay Module in an Arduino Project

A relay module acts like a switch to your circuit, opening or closing it depending on the electronic signal that is transmitted. It is ideal for controlling high ampere devices like a cooling fan, siren or garage door opener. However, it is important to be aware of the maximum voltage and current ratings of the relay to avoid electrical accidents.

Generally, a relay is made up of an electromagnet and two sets of switching contacts named as normally open (NO),normally closed(NC) & common contact (COM). The coil of the electromagnetic is wrapped around an iron core which gives a low reluctance path for magnetic flux. A movable iron armature is hinged to the yoke and linked to one or more of the sets of switching contacts. When the coil is energized, the magnetic field generated causes the armature to move and change the position of the switch contacts, thereby completing or interrupting the load circuit. The armature is then held in its new position by a spring.

The first step in using a relay is to ensure that it is compatible with the voltage levels and logic of your microcontroller or digital circuit. The next is to connect the power supply and the control signals. The final step is to connect the load to the output connectors. Once you have completed all of the connections, test your project by applying the control signals to the relay pins.

Relay modules are a versatile tool that can be used in various projects such as motion sensor lamps, smartwatch car remotes, and touchless doorbells. Their integration with microcontrollers offers the advantage of precise control and automation, making them an integral component in smart home systems.

There are many different types of relay modules available on the market, each designed for different applications and requirements. Some are designed to be used with AC appliances, while others are designed for use with DC appliances. The type of relay module that you choose will depend on the power requirements of the device or appliance you are controlling.

If you’re using a relay module with an Arduino, it will be connected to the Feather Board via a single output port. To activate the module, you’ll need to send a digital signal to the Feather board’s digital output pin through the loop() function. The signal will be set to HIGH, which will turn the relay on. A delay() function is then called, waiting for 2000 milliseconds (2 seconds) before turning the relay off by setting the pin to LOW.

To turn the relay off, you’ll need to send another digital signal to the Feather board through the digitalWrite() function. The second time this function is called, the relay will be turned off by the pin being set to LOW. You can repeat this process to turn the relay on and off as needed. If you’re using the relay module with a different type of board, be sure to check the relay’s documentation for details on pinout and connection.