Top 4 HATs for Raspberry Pi
Zero Relay and Relay 4 Zero
SB Components is back with two fresh Relay HATs for RaspberryPi Zero for all the IoT enthusiasts and electronics hobbyists. The new HATs are compatible with all Raspberry Pis.
Zero Relay - 2 Channel 5V Relay Board for Raspberry Pi
What is Relay?
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Relay is used for controlling an electrical load. In simple language, Relay is the electromagnetic switch which is used to provide a solution for controlling high current/voltage devices and make the appliances intelligent.
If we want to control any of our appliances through Raspberry Pi or micro controller we will be in need of these Relays which acts as the perfect interface for the AC load of the appliances and the DC load of the Raspberry Pi.
The relay is an electromagnetic device which consists of a coil and some electrical components. When the coil gets energized it automatically acts as an electromagnet and the switch gets closed. When it gets de-energized the coil loses its magnetic nature and the switch gets released.
The coil controls the switch, which is responsible for controlling the electrical load.
The relay consists of 5 pins- NO( Normally Open), NC( Normally Closed), COMM( Common) and 2 coil terminals.
ZERO RELAY (2 Channel)
Zero Relay provides a solution for controlling high current/voltage devices and makes your home appliances intelligent. It could be a nice solution for controlling devices that could not be directly controlled by RPi's Digital I/Os. The standardized shield form factor enables a smooth connection with Raspberry Pi and compatibles.
It is a 2 channel relay shield with 7A 240 Volts AC output and 10A 125 Volts DC output ratings. Zero Relay is designed for triggering at high voltage levels.
The relay channel 1 and 2 are connected with pin numbers 15 and 29 of the Raspberry Pi respectively. The channels are configurable and can be connected with other pins as well with the help of headers.
Features
- 2 High-quality 5V Relays that load up to 7A/240V(AC) or 10A/125V(DC).
- Control 2 appliances at once.
- 40 Pin Stacking Header.
- LEDs for indicating the status of each relay.
- Standardized shield shape and design.
- Make your home IoT enabled.
- Mounting holes provided.
- Compatible with all models of the Raspberry Pi such as Raspberry Pi 4, 3, 2, Zero and Zero W.
Relay 4 Zero (4 Channel)
Relay 4 Zero provides a solution for controlling low and medium current/voltage devices and makes your projects intelligent. It could be a nice solution for controlling devices that could not be directly controlled by RPi's Digital I/Os. The standardized shield form factor enables a smooth connection with Raspberry Pi and compatibles.
It is a 4 channel relay shield with 2A 120 Volts AC output and 2A 24 Volts DC output ratings. Relay 4 Zero is designed for triggering at low voltage levels.
The relay channel 1, 2, 3, and 4 are connected with pin numbers 31, 33, 35, and 37 of the Raspberry Pi respectively. The channels are configurable and can be connected with other pins as well with the help of headers.
Features
- 4 High-quality 3V Relays that loads up to 2A/24V(DC) or 2A/120V(AC).
- Control up to 4 appliances.
- 40 Pin Stacking Header.
- LEDs for indicating the status of each relay.
- Standardized shield shape and design.
- Make your home IoT enabled.
- Mounting holes provided.
- Compatible with all models of the Raspberry Pi such as Raspberry Pi 4, 3, 2, Zero and Zero W.
Connection of Relay HAT to Raspberry Pi Zero
Start with stacking the Relay HATs on the Pi and keep the power switch unplugged. Place the female headers of the Relay HAT over the male headers of the Raspberry Pi.
After placing the HAT properly on the Raspberry Pi, do the connections with your appliances/ devices. Turn on the power supply of the HAT.
To make communication between the relay and your Pi we need some installation. To get the example files in your Pi clone the following link:
For Zero Relay ( 2 Channel):
https://github.com/sbcshop/Zero-Relay
For Relay 4 Zero ( 4 Channel):
https://github.com/sbcshop/Relay-4-Zero
Open your Raspberry Pi terminal and write the command:
git clone https://github.com/sbcshop/Zero-Relay
git clone https://github.com/sbcshop/Relay-4-Zero
Once the cloning part is done you will find the test codes and other required files in your /home/pi directory of your Raspberry Pi. Run the test code ‘test2.py’ to control your device with Zero Relay and run code ‘test1.py’ to control your device with a 4 channel relay.
Conclusion
Relay HAT is a versatile product that can be used for many projects and for Automation. Relays are commonly found in home appliances. Therefore, Pi Zero Relays are a good option for Home automation and IoT projects.
