Eight MOSFETS 8-layer stackable HAT for Raspberry Pi with RS485, PWM control, and heavy-duty connectors for high-current and high-voltage DC loads.

Eight MOSFETS 8-layer stackable HAT mounted on Raspberry Pi with green connectors and DIP switches for industrial automation.

Eight MOSFETS 8-layer stackable HAT for Raspberry Pi with DIP switches, green pluggable connectors, and high-current DC load control features.

Eight MOSFETS 8-layer stackable HAT for Raspberry Pi with green connectors and DIP switches for high-current and high-voltage DC load control.

Eight MOSFETS 8-layer stackable HAT for Raspberry Pi with high-current and high-voltage DC load control, PWM, RS485/MODBUS support, and industrial automation features.

Eight MOSFETS 8-layer stackable HAT circuit board for Raspberry Pi with MOSFET drivers and connectors.

SKU: SM-I-006

Eight MOSFETS 8-Layer Stackable HAT for Raspberry Pi

Name: Eight MOSFETS 8-Layer Stackable HAT for Raspberry Pi
Brand: Sequent Microsystems
SKU: SM-I-006
Price: 90.0 USD
Availability: InStock

Four PWM Loads 12A/24V plus four PWM loads 4A/240V with status LEDs; RS485/MODBUS Port.

In stock

$90.00

Product variants

Overview

Eight-layer stackable MOSFET output HAT for Raspberry Pi with four high-voltage channels (4A/240VDC) and four high-current channels (12A/24VDC), all supporting 1 kHz PWM. Wide-range power supply (5V or 10–24VDC) includes an onboard DC-DC converter that powers the Raspberry Pi at 5V/5A.

4 high-voltage MOSFET outputs (4A/240VDC) + 4 high-current outputs (12A/24VDC)
PWM control at 1 kHz on all outputs — ideal for proportional load control
RS485/MODBUS standalone operation — no Raspberry Pi required
Hardware watchdog; galvanic isolation between high-voltage and high-current channels
Power from 5V or 10–24VDC wide-range supply; provides 5V/5A to Raspberry Pi
Eight-layer stackable; compatible with all Raspberry Pi versions from Zero to 5

Works with Open Automation Software

Compatible with widely used tools for control, monitoring, and system integration.

INTERFACES AND I/O

I/O's	Communication	Software Integration
• 4 High-Voltage Outputs CH1–4 (4A/240VDC)	• I2C Port to Raspberry Pi	• Command Line
• 4 High-Current Outputs CH5–8 (12A/24VDC)	• RS485/MODBUS Port	• Python Library
• Status LED per Output		• Node-RED nodes
• Push Button (GPIO 26 / pin 37)		• CODESYS Driver
		• OpenPLC Module
		• Home Assistant
		• Arduino Library
Other Features
• 1 kHz PWM on all 8 outputs — onboard processor enables proportional control independent of Pi
• Standalone MODBUS RTU slave operation — no Raspberry Pi required
• Wide-range power input: 5V or 10–24VDC; provides 5V/5A peak to Raspberry Pi
• Galvanic isolation between high-voltage (CH1–4) and high-current (CH5–8) channels
• Hardware watchdog monitors Raspberry Pi and power-cycles on lockup
• Eight-layer stackable — up to 64 MOSFET outputs per Raspberry Pi

DESCRIPTION

The Eight MOSFETS HAT adds eight independently controlled solid-state outputs to the Raspberry Pi. Channels 1–4 are rated for high-voltage loads up to 4A at 240VDC; channels 5–8 are rated for high-current loads up to 12A at 24VDC. All eight channels support 1 kHz PWM for proportional control of motors, heaters, lighting, and similar loads.

High-Voltage Outputs (CH1–4)

Channels 1–4 are rated at 4A/240VDC. Each output includes diode and TVS protection and is suitable for switching 240V AC or DC loads. Pluggable connectors simplify field wiring.

High-Current Outputs (CH5–8)

Channels 5–8 are rated at 12A/24VDC with TVS protection. These channels are galvanically isolated from the high-voltage channels, making it safe to power different load types simultaneously from the same card.

PWM Control

All eight outputs support 1 kHz PWM. The onboard processor handles PWM generation independently of the Raspberry Pi, so the duty cycle remains stable even when the Pi is under load. Ideal for proportional control of motor speed, heating power, and LED brightness.

RS485/MODBUS

When the TX and RX DIP switches are set to OFF, the card operates as a MODBUS RTU slave — any MODBUS master (PLC, SCADA, HMI) can control all outputs without a Raspberry Pi. Set TX and RX to ON to use the port as a passive bridge for the Pi. A full list of MODBUS registers is available on GitHub.

Hardware Watchdog

The onboard watchdog monitors the Raspberry Pi and power-cycles it if a reset command is not received within the configured timeout. Disabled at power-up; activated automatically after the first reset command is issued by the application.

Power Supply

Accepts 5V or 10–24VDC input. When a wide-range supply is used, the onboard DC-DC converter provides 5V/5A peak to power the Raspberry Pi — no separate Pi power supply needed. A resettable 2.5A fuse protects the board.

TECHNICAL DETAILS

CARD LAYOUT

Eight MOSFETS HAT for Raspberry Pi — card layout

MECHANICAL SPECIFICATIONS

Eight MOSFETS HAT Mechanical Specifications

DIP SWITCH AND STACKING

The onboard 6-position DIP switch configures the stack address and RS485 port behavior. Up to eight Eight MOSFETS HATs can be stacked on one Raspberry Pi; cards can be stacked in any order.

Eight MOSFETS HAT DIP Switch

Switch	Name	Function
ID0	Stack ID bit 0	Binary stack address bit 0 (LSB) — sets card level 0–7
ID1	Stack ID bit 1	Binary stack address bit 1
ID2	Stack ID bit 2	Binary stack address bit 2 (MSB)
TX	RS485 TX select	ON = Raspberry Pi drives RS485 TX; OFF = onboard processor drives TX (MODBUS RTU slave)
RX	RS485 RX select	ON = Raspberry Pi receives RS485 RX; OFF = onboard processor receives RX
TERM	RS485 termination	ON = enables 120 Ω termination resistor; set ON if this card is the last on the RS485 bus

ELECTRICAL SPECIFICATIONS

Power
Power supply	5V/5A or 10–24VDC/2.5A pluggable connector
Provides to Raspberry Pi	5V/5A peak
Onboard resettable fuse	2.5 A
Power consumption (card)	10 mA (outputs off)

High-Voltage Outputs (CH1–4)
Max voltage	240 V
Max current	4 A
R_DS(on)	200 mΩ at 10V gate drive

High-Current Outputs (CH5–8)
Max voltage	24 V
Max current	12 A
R_DS(on)	4.6 mΩ at 10V gate drive

Connectors
Connector rating	300 V / 15 A
Wire gauge	24–12 AWG

POWER REQUIREMENTS

Power supply: The card accepts 5V input from the Raspberry Pi or its own pluggable connector, or 10–24VDC from a wide-range supply. When a wide-range supply is used, the onboard DC-DC converter outputs 5V/5A peak to power the Raspberry Pi — no separate Pi supply is needed. The card itself draws 10 mA with all outputs off. A resettable 2.5A fuse protects the board.

SELF TEST

The card can be tested before installation by running a command from the command line. The card will cycle each output on and off at 0.5-second intervals. The LED indicators confirm that all outputs are functioning correctly.

COMMUNICATION INTERFACES

RS485 / MODBUS

The Eight MOSFETS HAT includes a standard RS-485 transceiver that can be accessed either by the onboard processor or by the Raspberry Pi. The operating mode is configured using the TX and RX switches on the DIP switch.

When TX and RX are set to ON, the Raspberry Pi communicates directly with any device that has an RS-485 interface. In this mode the card functions as a passive bridge, implementing only the hardware signal levels required by the RS-485 protocol. To use this configuration, the onboard processor must first release control of the RS-485 bus:

~$ 8mosind [0] rs485wr 0 0 0 0 0

When TX and RX are set to OFF, the card operates as a MODBUS RTU slave. Any MODBUS master — PLC, SCADA, or HMI — can read all inputs and control all outputs using standard MODBUS commands, with no Raspberry Pi required. A full list of supported MODBUS registers is available on GitHub.

The TERM position on the DIP switch enables the RS485 line terminator. Set it to ON if the card is last on the RS485 chain.

HARDWARE WATCHDOG

The onboard hardware watchdog monitors the Raspberry Pi. If the application fails to send a reset command within the configured timeout, the watchdog cuts power to the Pi and restores it after the configured off period. The watchdog is disabled at power-up and is activated automatically after the first reset command is received. Use 8mosind -h to see all watchdog commands.

Parameter	Value
Initial timeout period	Configurable — allows time for Raspberry Pi to boot and start the application
Running timeout period	Configurable — normal operating timeout
Off period	Configurable — duration the Raspberry Pi power is cut when timeout triggers
Reset counter	Stored in non-volatile flash; can be read or cleared at any time

COMPATIBILITY

Interface	I2C
GPIO used	GPIO2 (SDA), GPIO3 (SCL) — 2 pins only; remaining GPIO pins stay free
Max stack	8 cards of each type; different Sequent HATs can be freely mixed
Compatible with	All Raspberry Pi versions from Zero to 5 (40-pin GPIO header)

FIRMWARE UPDATE

The onboard microcontroller firmware can be updated in the field. The update tool downloads the latest firmware from Sequent Microsystems' servers and flashes it to the board over I2C.

WARNING: Stop all processes that access the card (Node-RED flows, Python scripts, cron jobs) before starting a firmware update. Accessing the card during an update may corrupt the firmware.

Running the Update

~$ cd ~/8mosind-rpi/update/

~/8mosind-rpi/update$ ./update <id>

Replace <id> with the board stack address (0-7). Full instructions including recovery procedures are available at:

https://github.com/SequentMicrosystems/8mosind-rpi/tree/main/update/README.md

DOWNLOADS

Schematics (PDF)	CAD	Software & Integrations
Schematic V2.0	2D CAD Drawing	Command Line
Schematic V4.0	3D STEP Model V5	Python Library
Schematic V5.0	3D STEP Model V6.1	Node-RED nodes
Schematic V6.1	3D Printing Enclosure	CODESYS Driver
		OpenPLC Module
		Home Assistant
		Arduino Library

COMPLIANCE

RoHS and REACH Compliance Declaration

WHAT'S INCLUDED

When you purchase the card you will receive the following items:

1. Eight MOSFETS HAT for Raspberry Pi

2. Mounting Hardware
	Four M2.5×19mm male-female brass standoffs Four M2.5×5mm brass screws Four M2.5 brass nuts

3. Connector Plugs for all Inputs and Outputs
	All required mating connector plugs for field wiring

QUICK START

Plug your card on top of your Raspberry Pi and power up the system.
Enable I2C communication on Raspberry Pi using raspi-config.
Install the software from GitHub:

~$ git clone https://github.com/SequentMicrosystems/8mosind-rpi.git

~$ cd 8mosind-rpi

~/8mosind-rpi$ sudo make install

~/8mosind-rpi$ 8mosind -h

The program will respond with a list of available commands. To read more about the CLI, please refer to the README file. If you would rather use a different platform, you can access the same functionality through dedicated, ready-to-use integrations in the Downloads tab above.

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Eight MOSFETS 8-Layer Stackable HAT for Raspberry Pi

Outstanding Product with Impressive Power Handling!

The Eight-MOSFETs stackable card for Raspberry Pi is an absolute game-changer! The build quality is solid, and the functionality is superb. It's easy to set up, and the documentation provided is clear and helpful. I've stacked multiple cards without any issues, and they work flawlessly with my Raspberry Pi projects. The high current capabilities of the MOSFETs are particularly impressive, allowing me to control heavy-duty loads with ease. This card has made managing multiple outputs a breeze, and I couldn't be happier with the performance. Highly recommended for anyone looking to expand their Raspberry Pi capabilities!

It never arrived - but it has now

Wow - these guys give you the personal service - my product didn't arrive and they asked for feedback - so I rated them bad - they then called me out for the bad review as they checked and my product did arrive - like the day after they asked for feedback - lol.

Anyway - it's arrived I'm sure it's fine - all happy now.

Best Mosfet Card Around

Giday everyone
If you need to control equipment then this is the card to Have. Fans to keep equipment cool or heating pads to keep the LIFO batteries warm & stop them from freezing then this is the card you need especially with the new added feature PWM control & using a PID routine that can be found in the Fan controller Hat REPO you have a winning combination.
Support is excellent & very quick to offer assistance. On a side not Alex is it possible to include the PID control from the Fan control Hat & have it included as standard in the Mosfet 8 IO card & the new soon to come 16 IO card

Thankyou Alex for all the assistance given. "U deserve a pay rise !!! "

Regards TonyD

Outstanding product

This board is fantastic, great for controlling a wide range of loads, trivially easy to interface with, comes with everything you need, scalable and flexible.

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