Sixteen Relays 2A/24V 8-Layer Stackable HAT for Raspberry Pi

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Sixteen Relays 2A/24V 8-Layer Stackable HAT for Raspberry Pi

Regular price $60.00


  • Sixteen Relays 2A/24V 8-Layer Stackable HAT for Raspberry Pi
  • All Relays with Status LEDs and NO contacts
  • Eight layer stackable to 128 relays
  • Pluggable Connectors 26-16 AWG wires
  • 24V/2A AC/DC on relay contacts
  • RS485 Port
  • General purpose push-button
  • 8 LEDs showing status of groups of 8 relays
  • Software self-test
  • Sixteen Relays Raspberry Pi
  • Command Line
  • Python Library
  • Node-Red nodes
  • OpenPLC module



    Perfect add-on to your project when you have to control large number of loads. Stackable to 8 layers, the card can add up to 128 relays to each Raspberry Pi in a compact form factor.

    Pluggable connectors make the 16-RELAYS card easy to use when multiple cards are stacked up. Relays have N.O. contacts and can switch 24V/2A AC/DC.

    Bicolor LEDs conveniently grouped on one side of the board show when relays are on or off. A power LED shows when power is applied. A reset switch permits shutting down the Raspberry Pi without the use of a keyboard and monitor.


    The card is compatible with all Raspberry Pi versions from Zero to 4. All stacked cards share the I2C bus using only two of the Raspberry Pi’s GPIO pins to manage all eight cards.  This feature leaves the remaining 24 GPIOs available for the user.


    The 16-RELAY card needs 5V to operate and can be powered from Raspberry Pi or from it's own 2 pin pluggable connector. The relay coils are also powered from the 5V.  The card draws 10mA with all relays off. Each relay needs about 80 mA to turn on. If power is applied to the board's connector, no other power supply is needed for the Raspberry Pi.


    A power LED shows when power is applied to the board. Due to space limitations, bicolor LEDs are used to shows the status of groups of 8 relays. 


    Up to eight 16-RELAY cards can be stacked on your Raspberry Pi. Each card is identified by jumpers you install to indicate the level in the stack. Cards can be installed in any order. The three position jumper  selects the stack level.

    For your convenience, two jumpers are provided with each card. For complex Home Automation tasks you can add to the stack one or more Home Automation cards with analog and digital inputs and outputs.


    The board is protected to accidental reverse power supply with a 5.8A, 39 mOhm MOSFET which breaks the ground line if reverse power is applied. 


    Shutting down the Raspberry Pi by turning off the power can result in SD Card failure. To prevent this, a shutdown command needs to be used before power cut-off. But this requires a monitor, keyboard and mouse connected to the Pi. 

    A momentary on push button installed at the edge of the board provides a convenient way to shut down the Raspberry Pi. The button is routed to pin 37 (GPIO 26). You need to write a script which monitors this pin, and if pressed for more than a desired time, issues the shut-down command.


    16-Relays Card Layout


    • Power Supply: 5V/8A pluggable connector with reverse polarity protection
    • On board resettable fuse: 3A
    • Relays: NO contacts, 2.5A/24 VAC/DC
    • Electrical endurance: minim 105 cycles at 1,800 operations per hour, full load
    • Mechanical endurance: minim 107 cycles at 18,000 operations per hour, no load


    8-RELAY Card Mechanical Specifications



    SIXTEEN Relays Downloads



    You can write your own application using the Command Line or Python Libraries provided. No programming is required if you use the Node-Red nodes we supply. You can drag-and-drop the functional blocks to design your application. Examples are provided at GitHub.


    The card can be tested before installation by running a simple command from the command line. The card will cycle each relay on and off at 0.5 seconds interval. The clacking noise of the relays and the lighting of the LEDs will assure that all relays are functioning.



    The 16-Relays Card can be installed parallel on a DIN-Rail using the DIN-Rail Kit Type 1, or perpendicular using the DIN-Rail Kit Type 2.


    When you purchase the 16-Relays Card you will receive the following items:

    1. 16-RELAYS add-on HAT for Raspberry Pi

    16-Relays for Raspberry Pi

    2. Mounting hardware

    • Four M2.5x18mm male-female brass standoffs
    • Four M2.5x5mm brass screws
    • Four M2.5 brass nuts
    Brass Mounting Hardware

    3. Two stack level jumpers

    Stack level jumpers
    4. Connector plugs
    8-Relay connector plugs


    1. Plug your 16-RELAYS card on top of your Raspberry Pi and power up the system.
    2. Enable I2C communication on Raspberry Pi using raspi-config.
    3. Install the 16-RELAYS software from
      • ~$ git clone
      • ~$ cd /home/pi/16relind-rpi
      • ~/16relind-rpi$ sudo make install
      • ~/16relind-rpi$ 16relind

    The program will respond with a list of available commands.

    Customer Reviews

    Based on 1 review
    Gary Newman
    Good Product

    My company has bought and will buy many more. We use them for lock controllers for mini-storage If you are looking for many DC relays under 24 volts and 2 amps this is the best I have found. They are stackable to 8 relay boards. You can also mix 8 relay boards and 16 relay boards; this helps match or get close to the numbers we need for each storage building. This company has also offered to make changes to the board to further meet our needs. I'm a grateful customer.