Home Automation
8-Layer Stackable HAT
for Raspberry Pi

Regular price $60.00


  • Eight relays with status LEDs and pluggable connectors
  • Eight layer stackable
  • Eight 12-bit A/D inputs
  • Four 13-bit DAC outputs (0-10V dimmers)
  • Four PWM 24V/4A open-drain outputs
  • Eight optically isolated digital inputs
  • Contact closure/Event counters up to 100 Hz
  • Four Quadrature Encoder inputs
  • 30 GPIOs (26 GPIOs from Raspberry Pi + 4 new)
  • Pluggable Connectors 26-16 AWG for all ports
  • On-board hardware watchdog
  • On-board resettable fuse
  • Reverse power supply protection
  • Brass stand-offs, screws and nuts included
  • Hardware self-test with loop-back cable
  • Open source hardware, schematics available
  • 32-bit Processor running at 48MHz
  • Command line 
  • Python Library
  • Node-RED Nodes
  • Domoticz Plugin
  • OpenPLC example integration
  • Firmware Update



Latest news: The Home Automation HAT has been redesigned to use only pluggable connectors. Due to the large number of I/Os, the previous version used a 40 pin, right angle header. By removing the N-C contacts of the relays (seldom used), we made enough room on the periphery for pluggable connectors with just a minor increase in board dimensions. 

Despite the crowded layout, we also added a DC-DC, 5V to 12V step up power supply to power the 0-10V outputs. Now you can control four dimmers without the need for an external, 12V power supply.

We also added a general purpose push-button, wired directly to a Raspberry Pi GPIO pin. You can write a script which captures the pin state and use it to turn on a relay or an output, or to shut down the Pi when a keyboard and monitor is not available.

Ideal solution for your Raspberry Pi HOME AUTOMATION projects. Read temperatures in up to 8 zones with analog inputs. Control your heating and cooling system with the 8 onboard relays. Add another 8-RELAYS to control your sprinklers, or 4-RELAYS to control high voltage appliances. Use the 8 optically isolated digital inputs for your security system. Activate the hardware watchdog to monitor and power cycle the Raspberry Pi in case of software lockup. Control four-light systems with the four PWM open-drain outputs (you supply external power up to 24V). Control four light dimmers using 0-10V outputs.


The card is compatible with all Raspberry Pi versions from Zero to 4. It shares 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 Home Automation card needs 5V to operate and can be powered from Raspberry Pi or from its own 2.1mm barrel connector. The tip is +5V and the ring is ground. The onboard relay coils are also powered from the 5V. A local 3.3V regulator powers the rest of the circuitry. The card needs 50mA to operate with all relays off. Each relay needs up to 80 mA to turn on.


The 8 on-board relays have contacts brought out to heavy duty pluggable connectors,  which make the card easy to use when multiple cards are stacked up. Relays are grouped in two sections of four relays each, with one common terminal and one N-O contact for each relay. Relays are rated 10A/24VDC and 250VAC, but due to the board geometry limitation, relays 6 and 7 can switch 3A and 24V, while all the others can switch 6A and 24V AC or DC. You can switch large loads of up to 8A and 240VAC using our 4-RELAY cards, which also adds four extra inputs.

Status LEDs show when RELAYS are ON or OFF.


Up to eight Home Automation 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 on the upper right corner of the card selects the stack level.

Stack Level Jumpers

For your convenience, two jumpers are provided with each card.


Home Automation for Raspberry Pi with Pluggable Connectors


The Home Automation is accompanied by a Credit Card size, plastic laminated card which shows the I/O pinouts. Keep it handy. The back of the card shows the Raspberry Pi GPIO Connector pinout.

Home Automation Pinout


  • Power supply: Pluggable Connector, 5V/3A
  • Power consumption: 50mA (all relays off), 700mA (all relays on)
  • On board resettable fuse: 3A
  • Open Drain outputs: maximum 3A, 24V
  • Relays 1,2,3,4,5,8: N-O contacts,  6A/24VAC or DC
  • Relays 6,7: 3A/24VAC or DC
  • Analog Inputs:
    • Maximum input voltage: 3V
    • Input Impedance: 50 KΩ
    • Resolution: 12 bits  
    • Sample rate: 250 samples/sec.
  • DAC Outputs:
    • Resistive load: Minimum 1 KΩ
    • Accuracy: ±1%
  • Opto-isolated Digital Inputs:
    • Input Forward Current: Typical 5 mA, maximum 50 mA
    • Input Series Resistor: 1K
    • Input Reverse Voltage: 5V
    • Input Forward Voltage: 25V @ 10 mA
    • Isolation Resistance: Minimum 1012 Ω


Home Automation for Raspberry Pi with Pluggable Connectors


Open Source Hardware Schematic

2D CAD drawing

User's Guide



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.


Groups of three inputs and outputs can be self-tested with the help of a loopback cable. The cable can be purchased as an accessory to the card, or you can make it yourself using three of the connectors provided with the kit. 

Home Automation Loopback Cable

1. TEST the GPIO and OPTO-INPUTS 1-4

Insert the cable on the left side of the card, as shown in the following picture, and run the self-test command

Home Automation testing GPIO and OPTO-INPUTS


Insert the cable on the bottom side of the card, as shown in the following picture, and run the self-test command.

Home Automation Testing the Analog Inputs and Outputs


Insert the cable on the right side of the card, as shown in the following picture, and run the self-test command.

Testing the Open Drain Outputs and Opto-Inputs 5-8


Without the loopback cable, run the command relay_test. Relays will cycle on and off in sequence and the corresponding LED's will turn on and off.


Home Automation Loopback Cable


The analog inputs and outputs are calibrated from the factory with 1% precision. Field calibration up to 0.1% can be obtained using a precision voltage meter.  Calibration instructions coming soon.


The card firmware can be updated in the field by running a command. The update is made with the latest firmware version located on our servers. More instructions about the process can be found on GitHub. Please make sure there is no process, like Node-Red or python scripts, that tries to access the card during the update process.


The Home Automation card contains a built-in hardware watchdog which will guarantee that your mission-critical project will recover and continue running even if Raspberry Pi software hangs up. After power up the watchdog is disabled, and becomes active after it receives the first reset.

The default timeout is 120 seconds. Once activated, if it does not receive a subsequent reset from Raspberry Pi within 2 minutes, the watchdog cuts the power and restores it after 10 seconds.

Raspberry Pi needs to issue a reset command on the I2C port before the timer on the watchdog expires. The timer period after power up and the active timer period can be set from the command line. The number of resets is stored in flash and can be accessed or cleared from the command line. All the watchdog commands are described by the online help function.



The Home Automation 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.


The Smart Fan provides a stackable cooling solution for Raspberry Pi. Its on-board processor powers the fan just enough to maintain the preset temperature of the Pi.


Break-out boards provide a convenient and robust way of accessing the IO pins. For screw-mount wiring you can use the Break-Out Kit Type 1. The Break-Out Kit Type 2 provides wiring with pluggable connectors.


When you purchase the Home Automation Card you will receive the following items:

1. Home Automation Stackable Card for Raspberry Pi with Self-test card

Home Automation for Raspberry Pi

2. Mounting hardware

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

3. Two stack level jumpers

4. All required connector plugs

Home Automation Card Connector Plugs
5. Laminated Plastic Card showing IO Pinout
Home Automation Card Pinout


  1. Plug your 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 software from github.com:
    • ~$ git clone https://github.com/SequentMicrosystems/ioplus-rpi.git
    • ~$ cd /home/pi/ioplus-rpi
    • ~/ioplus-rpi$ sudo make install
    • ~/ioplus-rpi$ ioplus

The program will respond with a list of available commands.