HAT RACK – DIN Rail Mount for Pi HATs

HAT RACK – DIN Rail Mount for Pi HATs

HAT RACK allows multiple Raspberry Pi HATs/pHATs to be connected to a single Raspberry Pi without the need for any ribbon cables or messy wires. The plug & play design allows you to create tidy, professional looking setups easily!

Check-out our homepage: hatrack.io

HAT RACK What's In The Box

How It Works

Stackable HATs have become the de facto standard in the Raspberry Pi community, but stacking HATs together can make them difficult to get to, awkward to maintain and can lead to excessive heat built-up.

HAT RACK solves this by separating the stack into an easier to manage array. Each board is connected together in parallel which is perfect for I2C based HATs such as Raspberry Pi’s Sense HAT.

Features

There are other HAT mounts available, so how is HAT RACK different?

  • Connect 3 HATs or 6 pHATs per board
  • Plug & Play Raspberry Pi or Pi Zero
  • Daisy chain multiple boards
  • DIN rail mountable
  • External power in
  • BCM pin numbering
  • Gold flash plated pins
  • UL, CE and RoHS (lead free) compliant
HAT RACK Final Prototype

History

HAT RACK is the big brother to our DINPi board, and is backwards compatible! As home automation installers, we originally created DINPi for use in some of our installs back in 2018. We needed a quick and easy way to mount Raspberry Pi onto a DIN rail with support for various HATs.

We discovered a simple way to directly attach a Raspberry Pi upside down without any special adaptors by mirroring its pinout. This means the Pi can be mounted flat so it fits inside smaller domestic DIN rail enclosures, inside access panels or anywhere you can fit a DIN rail.

Many of our automation setups are hard-wired to ensure robust and reliable operation and avoid the need for battery operated receivers. This often involves using relays to switch on lights, control motorised blinds, gates, you name it! Most of these devices do not operate at the same voltage levels as Raspberry Pi, so need to be separated and electrically insulated to make the installation safe for the user and/or installer. The easiest way to achieve this is using an industry standard DIN rail enclosure.

We often combine different HATs to create bespoke setups, we’ve even developed some of our own! DINPi was a great way to solve this problem for us, so much so we found ourselves using 3 or 4 of them each time. So we decided to create a new & better version, enter: HAT RACK.

Development

Despite its straightforward design, HAT RACK has been in the pipeline for quite a while. We’ve gone through several iterations, polishing our design each time to make it as easy to use as possible.

HAT RACK has been fully field tested using our own I2C based HATs, such as CTRL HAT; a solid state relay HAT for directly switching high current loads, based on the well documented MCP23017 I2C expander.

We’ve created a Python script to test multiple MCP23017 HATs in sequence, which can be found here. HAT RACK is the perfect companion for these and other I2C based HATs.

Compatability

HAT RACK is compatible with all 40-way Raspberry Pi models and clones.

  • Raspberry Pi 1 Model A+/B/B+
  • Raspberry Pi 2 Model B
  • Raspberry Pi 3 Model B/B+
  • Raspberry Pi 4
  • Raspberry Pi Zero
  • Asus Tinker Board
  • Orange Pi
  • Odroid

We’ve worked hard to make the design as solid as possible, ensuring compatibility with official and 3rd party HATs & pHATs. We’ve left enough space to allow for overhanging connectors and cables, even when daisy chained together.

We’ve added BCM pin numbering to make it easy to identify the pinouts and an external power-in so the boards can be powered from a dedicated 5V power supply if desired.

HATs which make use of the PoE header (such as the official PoE HAT), are supported by attaching directly to the Pi using extended/stacking headers such as this from The Pi Hut.

Of-course, not all HATs will play nicely together. For non bus based HATs there may be some limitations which may need to be considered. You may need to check what pinout your HATs/pHATs are using. A great resource for this is Pinout.xyz.

Compliance

  • UL 796 certified manufacturer
  • RoHS compliant (lead free)
  • CE marked

Parts List

  • 2×20 pin header – For mounting HATs/pHATs – x6
  • 2×20 pin socket – For mounting Raspberry Pi upside down
  • 2×20 pin 90 degree header
  • 2×20 pin 90 degree socket
  • 3.5mm pitch terminal block
  • 100 µF Electrolytic capacitor
  • DIN rail adaptor (Phoenix Contact 1201578 or generic) – x3

3D Model

We have released an interactive 3D model which you can use in your designs.

Dimensions

HAT RACK Dimensions

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