Home Automation V4 8-Layer Stackable HAT for Raspberry Pi

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Home Automation V4 8-Layer Stackable HAT for Raspberry Pi

Regular price $70.00


  • Home Automation V4  8-Layer Stackable HAT for Raspberry Pi
  • Eight relays with status LEDs and and N.O contacts
  • Eight 12-bit A/D inputs, 250 Hz sample rate, 0-3.3V
  • 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 500 Hz
  • Four Quadrature Encoder inputs
  • 26 GPIOs from Raspberry Pi available
  • 1-WIRE and RS485 communication ports
  • 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 64MHz
  • Uses only I2C port (address 0x28..0x2f ), all GPIO pins available
  • Command line 
  • Python Library
  • Node-RED Nodes
  • Domoticz Plugin
  • OpenPLC example PSM integration
  • Arduino Library
  • Firmware Update
  • OpenPLC module


Latest news: 
The Home Automation HAT uses only pluggable connectors. In addition, the latest release (V4.0 and up) has two new communication ports: 1-Wire and RS485.
The card uses only 5V power. On-board step-up power supply generates 12V to power the 0-10V analog outputs.
A general purpose push-button, wired directly to a Raspberry Pi GPIO pin, can be used to shut down Raspberry Pi without a keyboard, or to force any output to a desired state.
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. 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 pluggable connector. The onboard relay coils are also powered from the 5V. An on-board 5V to 12V step-up power supply generates the voltage to drive the 0-10V analog outputs. 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, the relays can switch only 3A 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.
For your convenience, two jumpers are provided with each card.
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.
ERRATA: The plastic card has not been updated to show the 1-WIRE and RS485 ports which have replaced the four GPIO ports in the upper left corner.
  • 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



You can write your own application using the Command Line , Python Libraries or Arduino Library 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.
Without the loopback cable and with no loads connected to the relays, run the command relay_test. Relays will cycle on and off in sequence and the corresponding LED's will turn on and off.
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.


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. 
NOTE: In Version 4 and up the four GPIO connector in the upper left has been replaced with RS485 and 1-Wire ports. TEST #1 bellow applies only for cards from Version 3.
1. TEST the GPIO and OPTO-INPUTS 1-4
Insert the cable on the left side of the card, as shown in the picture below, and run the self-test command
Insert the cable on the bottom side of the card, as shown in the following picture, and run the self-test command.
Insert the cable on the right side of the card, as shown in the following picture, and run the self-test command.
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
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
5. Laminated Plastic Card showing IO 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.

Customer Reviews

Based on 22 reviews
Amazon Customer
Works Perfectly with RPI-4

This relay Hat works perfectly on a Raspberry Pi4. It stands high enough above the board with the stand offs provided to allow for a cooling fan under the hat. The fan is needed on the PI4. Fan is GeeekPi Raspberry Pi 4 Aluminum Heatsink with PWM Controllable Fan from Amazon also. I'm using the 8relind program for command line control for the relay hat. This software is downloadable from the link provided with the hat. It is very easy to implement using simple shell scripts. For example, 8relind 0 write 1 on turns on relay 1 on board 0. state=$(8relind 0 read 1) returns 0 (off) or 1 (on) for relay 1 board 0. The relays are controlled using I2C which frees up all of the GPIO pins and avoids having to run individual jumper wires to control external relays. While I will only use 2 Hats stacked, the I2C addressing supports up to 8 boards or 64 relays!! The 'kit' comes with everything you need except the Raspberry Pi of course. While I'm using it on a PI-4, I see no reason it wouldn't work on any RPI version with 40 GPIO pins. So that would be RPI B+ and above.

Aastan Gadson
Excellect product!

I was looking for a relay hat with more than 4 relays for a long time. This product just fell from heaven. It is Intuative and easy to set up.

Not exactly a looker but it works very well

I'm using this for a hydroponic system controller so I2C and Python library were must haves. The stackable design was candy. All together it's a good product at a reasonable price.

Simon Kogler
Very Easy to Use

The Sequent boards have so far been fun and easy to work with. Libraries and documentation are fine and everything has either directly worked or we received competent support. We used python in our projects so far.

Pat Pat
Quality and flexible hardware for Raspberry Pi4 that works with OpenPLC

After struggling with trying to get my old PiFace HAT to run with OpenPLC, I was pleasantly surprised when I came across the Sequent Microsystems Home Automation HAT.Here are my observations after working with it for a few days:LikesHardware appears to be well-built and of good qualityOptically Isolated Inputs eliminate concerns about pull-up or pull-down resistors in Raspberry Pi inputsPlug-in connectors reduces chances of accidental damage during wiringIntegrated support for free open source OpenPLC programming software and RPi run-timeOther programming options supportedBuilt-in support for Modbus TCP through OpenPLCInexpensive for Home Automation applicationsGood for learning industrial automation software and hardware interfacesSelf tests that ease trouble-shooting of the board itselfDislike (slightly)Analog Inputs of 0-3V instead of 1-5V (4-20mA) industrial standardOn balance, I would rate it 5-stars.