Circuit boards

We publish a lot of free open source software on the directors GitHub pages. This includes a number of circuit board designs and associated software. Many of these circuits can be purchased here, or from Amazon. Please see notes below.

If you have any questions, please contact the specialist PCB support team at (please don't call the normal sales staff).

IMPORTANT: These are sold as components only

These are sold as assembled printed circuit boards, much as if you were ordering boards from a PCB manufacturer, and as such are not a complete product. They typically come in a PCB biscuit with blank panels you have to snap off (they are V cut, so snap off easily). You can use them as you wish, and they are ideal for a hobbyist or making prototypes, but if you were to use them to make a product that you put on the market you are responsible for ensuring EMC and regulatory compliance for your product as a whole. They do not come with a case or housing, so please ensure you observe ESD precautions to avoid damage (which may not immediately be apparent). Just to be clear, if popular, we may decide to make some of these a "product" in the future, with certification for CE/UKCA marking, but these are current only sold as components - assembled circuit boards.


Support for the physical boards is provided by us, i.e. we will replace a faulty board, or you can return to Amazon if you purchased from them. Contact for help.

Support for software, bugs, and feature requests, are handled on the relevant GitHub pages via issues and discussion pages.


Most boards have open source software available on the GitHub links shown. This is normally pre-loaded for your convenience, and then allows over the air updates over WiFi. Note that any software pre-loaded is just for your convenience and not part of what you are buying - it is open source software issued on a GPL licence which is "AS IS" with no warranty.

Development environment

You can also make your own software for these boards. You will need a suitable lead to program them...

  • Older boards before ESP32-S3 used had a 5 pad serial programming header, and a suitable lead is the tasmotiser board. A few had a UART and USB-C connector instead.
  • Boards with ESP32-S3 generally have a direct USB-C connector, but some also have a USB header (4 pads) for programming in the panel. Some have only such a header. You would need a suitable lead made up for this. These usually also have a 5 pin serial header.
  • The latest boards with ESP32-S3 generally have a direct USB-C connector, but some also have a tag-connect compatible USB header which works with a TC2030-USB-NL lead.

These modules are based on the ESP32 processor, so the ESP IDF development environment is recommended (though there is also an Arduino based IDE).


Boards with a processor (most of them) are all designed around the ESP32 processor. The latest boards use the ESP32-S3 processor (specifically the ESP32-S3-MINI-1-N4R2 module). Some of the older designs (and where space is an issue) use the ESP32-PICO-MINI-1-N8R2 module. There are builds for several variants of processor including the SOLO (single CPU) versions in the Shelly devices.


Schematics and PCB layout are all included in KiCad format, along with production files. Note that the AJK and A&A logos are trademarks so should be removed if you make your own boards.


For most boards a 3D printable case design is also included on the GitHub link.

Ongoing development

The boards all have a date code, and the GitHub project may have moved on since the boards were made. If you have any problems it is worth checking out the project from the corresponding date. This will provide the correct schematic. This is particularly important for the 3D printed cases based on the PCB design as other date codes may not fit. This also means boards you buy may not look exactly like the latest image or circuit. Colour may also vary.

If using the open source software, this is usually set to auto updated periodically - this can be disabled in settings if you prefer. Solar System has its own software update process from the management system.


Many boards make use of Phœnix Contact connectors as they have push in wire plugs (which work best with solid wire). So some products may be shipped with these, to avoiding need for a crimp tool. Most things could use 0.1" square pin headers instead if you are prepared to do some soldering. Some use screw terminals. See details for the individual board.


If you are interested in a board that has an order link - you can just order it. Some are listed on Amazon, and include a link. But if not, or you have any other questions, please contact We're happy to consider having some more made if there is interest.

If you need similar boards designed, do get in touch. We can usually get batches of boards within 2 weeks if needed.

Shipping outside the UK

We do not ship these outside the UK at present - the hoops needed to handle this are not something we are keen to take on at this point. However, we have had reports from customers that a forwarding service like forward2me may be suitable for shipping outside the UK, and apparently works with Amazon. We don't have direct experience of them, and so are not recommending or endorsing them as such, but if you want these sent to a non UK destination such a forwarding company may be the answer. I have no idea how they handle the export issues, but if we are shipping to a UK address, it is not our problem, thankfully. Amazon are apparently shipping some boards outside the UK as well.

Contact Sales

phone 03333 400222
(Mon-Fri 9am-5pm)
sms 01344 400222

Contact Support

phone 03333 400999
(Mon-Fri 8am-6pm,
Sat 10am-2pm)
sms 01344 400999