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We ship to most regions worldwide. You can select the shipping carrier at checkout. USPS usually delivers in 7-20 days to most countries, while UPS or DHL can deliver in 1-3 days.

Shipping costs depend on the item you’ve ordered and the country where it’s being delivered and it is calculated at checkout. 

If your order value is more than $15 we provide free shipping within the U.S. After placing your order, enter the code FREE-SHIPPING at checkout.

Theoretically, all our stackable cards can be intermixed in almost any configuration, up to eight of each type. 

In practical terms, stacking more than eight cards becomes mechanically challanging.

At this point six of our cards can process digital inputs. The maximum frequency of input signals, or transitions per second that can be sensed, is the following:

1. Home Automation Card has 8 optocoupled inputs prepolarized at 5V and can count transitions up to 125Hz.
2. Industrial Automation Card has 4 optocoupled inputs that can count transitions up to 500Hz
3. Building Automation Card has 8 dry contacts inputs that can read signals up to 500Hz

The following cards can read both AC and DC signs have a low pass filter at 25 Hz and can count up to 10 transitions per second:

1. Sixteen Digital Inputs Card, which can read 16 AC/DC signals from 3V to 24V
2. Four Relays four Inputs Card, which can read 4 AC/DC signals from 3V to 240V
3. Eight HV Digital Inputs Card, which can read 8 AC/DC signals from 3V to 240V

All our cards use only the I2C pins from the Raspberry Pi GPIO connector to communicate with Raspberry Pi, leaving the other 25 pins available for your use.

Cards with on-board watchdog control the power to the Raspberry from the local processor. If the watchdog is activated, power is cut off if Raspberry does not access the I2C port in the preset time interval.

Cards with RS485 tranceiver use also one serial port of the Raspberry Pi. If enough resources are available, the RS485 port might be connected to the local processor as well, and jumpers are provided to decide who is controlling the transceiver.

Cards on on-board push-button have the push-button connected to pin 37 of the GPIO connector. The push-button is also connected to the local processor, if present and enough resources are available. 

Cards without a processor use I2C expanders to control the I/Os.

The only exception to all the rules is the I/O Learning Card, which uses the resources of the Raspberry Pi and is not stackable.

We sell worldwide. For small orders, the cheapest shipping carrier is USPS, which will pass the package to your local postal service.

For larger orders we use UPS and DHL. Shipping cost is calculated at checkout.

We keep RoHS and REACH Compliance Declarations on file for all our cards. If you need a local copy you can download it here:

Building Automation 8-Layer Stackable HAT for Raspberry Pi

Eight HV Inputs 8-Layer Stackable HAT for Raspberry Pi

Eight MOSFETS 8-Layer Stackable HAT for Raspberry Pi

Eight Relays 8-Layer Stackable HAT for Raspberry Pi

Four Relays four Inputs 8-Layer Stackable HAT for Raspberry Pi

Home Automation 8-Layer Stackable HAT for Raspberry Pi

I/O Learning Card with Full Node-RED Tutorial for Raspberry Pi

Industrial Automation 8-Layer Stackable HAT for Raspberry Pi

RTD Data Acquisition 8-Layer Stackable HAT for Raspberry Pi

Sixteen Digital Inputs 8-Layer Stackable HAT for Raspberry Pi

Sixteen Relays 8-Layer Stackable HAT for Raspberry Pi

Smart Fan HAT the Best Cooling Solution for Raspberry Pi

Super Watchdog HAT with Battery Backup for Raspberry Pi

Three 40A/240V Relays RS485 Daisy-chainable HAT for Raspberry Pi

The following diagram shows how to connect your load to any of our cards with an open drain output. You have to provide the power supply and to connect the load as shown. Make sure the DC voltage of the power supply does not exceed the specifications of the card.

Yes, you can stack them, but mecanically the Home Automation card needs to be on top of the Industrial Automation card.

Since each card can be stacked to itself, you can stack up to eight Industrial Automation cards on top of the Raspberry Pi, and add up to eight Home Automation to the assembly.

Yes, you can use all our cards with ROCK PI 4.

Because our drivers are made for Raspberry Pi, some changes need to be made.

Here a step-by-step example for setting up your ROCK PI 4 for using the  Home Automation For Raspberry Pi Card :

1) Install Debian https://wiki.radxa.com/Rockpi4/Debian  (u/p:rock/rock)
2) Install mraa library : https://wiki.radxa.com/Rockpi4/dev/libmraa
3) Turn on the I2C port  sudo nano boot/hw_intfc.conf   | turn on i2c7
4) Install build tools: sudo apt-get install build-essential python-pip python-dev python-smbus git
5) Get the repository: ~$ git clone https://github.com/SequentMicrosystems/ioplus-rpi.git
6) Change "/dev/i2c-1" with "/dev/i2c-7" in ioplus-rpi/src/comm.c
7) cd ioplus-rpi/
8) Install the ioplus command line interface: ~/ioplus-rpi$ sudo make install
9) Connect the card and test the software ioplus -list shuld return the cards connected to the ROCK PI.

Please use the Contact Us form to send your question, or email us to support@sequentmicrosystems.com

We answer most inquiries in 24 hours, and if your question is of general interest we'll post the answer as well

You can use intrerrupts on Raspberry Pi, but you have to write your own interrupt handler and activate the GPIO pullup, which is 50K to 65K.

Our cards with digital inputs send an interrupt signal to Raspberry Pi on input transitions.

Cards with analog inputs can be programmed to interrupt on input thresholds.

16 Inputs V2: GPIO11, Pin 23; V3 (Easy): GPIO26, Pin 37

8 Inputs V1: GPIO05, Pin 29; V2: TBD

12 Inputs V1: GPIO26 (Easy), Pin 37

4 Rel/4 Inp V2: N/A; V4 (Easy): GPIO26, Pin 37

RTD V6: N/A; V7: N/A; V8 (Easy): GPIO26, Pin 37 (use PA0)

HOME V1: N/A; V2 (Easy): GPIO26, Pin 37 (use PA1)

IND V3: GPIO13, Pin 33; V4 (Easy): GPIO26, Pin 37

BAS V4: GPIO10, Pin 19; V5 (Easy): GPIO26, Pin 37

Considering all Sequent I/O cards communicate I2C, you can scan the bus for attached devices and detect which cards are connected and what stack-level settings they have. One little problem here, there are a few cards (we started replacing them) that use the same IO expander chip, so you will not be able to detect the exact type of the connected card. Here is the list of the I2C addresses for all cards, including the obsolete ones.

• Rasppishop.de in Germany
• ThePiHut.com in England
• RPishop.cz in Czekia

We did not test our cards with odroid but we think it will definitely work. The 40 pin connector for Odroid and raspberry are electrically identical. We have a Python library and command line interface written in C  which can be used on any linux os . All our cards use I2C port for communication , on raspberry i2c-1 and on Odroid i2c-0, so you need to change the port number in the source code.

All our cards are stackable to eight layers, with a few exceptions

1. 3-RELAY card can be only daisy chained through the RS485, it is too thick to be stacked
2. Super-watchdog is not stackable since it does not make sense
3. Smart Fan is stackable only to two layers

Some "dumb" cards implemented with I/O expanders (8-RELAYS, 8-INPUTS, 16-RELAYS, 16-INPUTS and 8-MOSFETS) share the same I/O address due to market shortages, so they can be stacked only up to combined eight.

The other "smart" cards can be stacked eight of each. This means you can create unreasonable long stacks. 

We tried to find if there is a practical limitation caused by the I2C communication. We tested a stack of 30, which is unreasonably long, and it worked without a glitch.

All our digital input cards have opto-isolated inputs.

In order to also read AC signals, we filter the signal at the output of the optocoupler.

The cards without a processor have a hardware filter. The cards with a processor filter the signal in software.

The cards without a processor can read signals up to 12Hz, square wave 50%. This group includes: 

• 16-LV-INPUTS
• 8-HV-INPUTS

The cards with a processor can read signals up to 4Khz, and measure PWM signals up to 500Hz. This group includes:

• 4-RELAYS-4-INPUTS
• Home Automation
• Industrial Automation
• Building Automation (universal inputs not optocoupled)

To set the Raspberry Pi time from the RTC for the Industrial Automation card, run the following command from the command line or from cron:

t=$(megaind 0 rtcrd) | sudo date --set "$t"

Change the megaind command with the appropriate one for the card you use. 

We wrote a full script which keeps the two systems in sync. If the network is active, it sets the RTC time from Raspberry Pi.

If the network is down, it sets the Raspberry Pi time from the RTC. You can download the script from GitHub, with instructions HERE.