Jun 24, 2023


With the Raspberry Pi Pico in mind, UK company OpenLX SP has answered the question: ‘how do I temporarily mount a castellated solder-down PCB module?’.

The answer is a connector dubbed Clipzin, which is used in pairs to create a socket for the un-modified castellated module.

However, although the connectors are surface mount, they will not mount directly onto the standard Raspberry Pi defined surface-mount solder footprint used to host Picos, as the Clipzin has guide pegs which need holes in the board, and there are other differences: "There are holes needed to place the Clipzin on the PCB when soldering," a Farnell spokesman told Electronics Weekly. "The solder pad spacing along the length is the same as the Pico surface-mount footprint, however you have to allow for the Pico PCB width [21mm] plus 3.64mm."

Gold-plated conductive parts in the Clipzin engage with the castellated edges of the module to both make electrical connections and mechanically restrain the module. There is also an insulated tooth that swings in to prevent the module from shaking or vibrating loose.

"This makes it the ideal solution for the development environment, while also providing the security required for production applications," according EDAC Europe, the company selected to manufacture OpenLX SP's design.

Farnell, is the distributor chosen to stock and sell 20 way Clipzin connectors for Pico.

It describes them as "a semi-permanent way to mount one PCB on another", and said that they allow "customers to produce one design that can be customised for flexibility, and to offer variants, reducing the need to stock many versions".

While Farnell and EDAC have launched with the 20 way version, 6, 8 and 17 way types are in the pipeline, and a similar part has been designed for the Arduino Nano.

OpenLX SP is the company behind PiFace and CodeBug.

"We have a history of bringing products to market with Farnell," said its engineering director Andrew Robinson. "Combined with EDAC's years of experience it's a fantastic partnership to develop a connector that makes it easier for people to use modules such as Raspberry Pi PicoW."

Farnell is stocking the 20 way Clipzin in pairs or on reels

EDAC's Clipzin page is here

The standard Raspberry Pi Pico surface-mount solder footprint can be found on page 9 of this document

The Clipzin footprint and drill pattern can be found in this Farnell data sheet

Steve Bush