We are all surely up to date on the recent release of the first official silicon product from the Raspberry Pi Foundation — the RP2040 MCU, along with its associated development board, the Pi Pico — the first dev board to use this ultra-new silicon.
This homegrown silicon has made waves throughout the community, not only as a notable change of tact from the Foundation — a home rolled MCU is no small undertaking! — but since then, from many many demonstrations that showcase the sheer power of this dual-core Cortex-M0 MCU!
From retro gaming, to using the parts PIO to sit as a front end to PulseView for signal capture and analysis (seen below), the RP2040 grows more powerful each day, as users start to poke and prod with the peripherals packed into the part.
The thing is, despite the sheer power of this QFN packaged part, being more than capable of interfacing to — and driving — practically every single Raspberry Pi HAT and Bonnet on the market, the form factor of the Pico forgoes the 40-pin header that will be familiar to so many of us.
While certainly more breadboard friendly, there's a distinct difference in how to attach your existing hoard hat hardware, when comparing the very obvious differences in I/O placement.
It's not surprising, the SoC used in the conventional Pi format boards has external RAM busses, a USB hub thrown in, a network PHY, Wi-Fi and a lot more.
The RP2040 is still a beast of a chip, but it's clearly targeting the lower end of the embedded market — or perhaps, it's fairer to say, it's targeting the bits where a full blown Pi is often overkill for the application at hand.
There's the first and foremost idea that came to the minds of many - a reimagining of the Pico board itself, such that it maps as many of the RP2040 IO from the chip itself, to the appropriate pin header locations, so as to enable the IC to talk to the HATs and Bonnets that the Pi SoC used to knock boots with.
@arturo182 catapulted himself into that creation, with his well received, work-in-progress Zero 2040. This board respectfully finds a new home for a poor RP2040, liberated from its parental Pico board, barely as soon as the packaging had been opened!
This board is arguably a work of art itself, not only a reference in how to quickly turn an idea into a rev 1, but also in terms of the attention paid to even the silkscreen markings!
The thing is, there's a lot to get right — which Arturo is clearly capably churning through — before release.
There must be an easier way to get hacking with you HATs, perched on top of the Pi Pico...
If all you want to do is get your HATs and Bonnets perched upon the I/O of your Pi Pico, an interposer might be just the ticket, and the gang over at Red Robotics have jumped into action, producing just that, in the form of the Pico 2 Pi Adaptor Board.
It's as simple as it looks, with what looks like a single, two-layered PCB perfectly able to put the Pi Pico I/O into the corresponding positions expected by the 40-pin header 'standard.'
Comparing the mapping of the I/O to the A+ standard — (a good enough reference I'd say), we can see that nearly anything that is based around your standard digital interfaces — SPI, I2C, UART, and GPIO is likely going to play nicely with this Pico 2 Pi Adaptor plate!
Matching the constellated edge contacts of the Pico module is a nice touch, meaning that stack height of the boards is going to have very little risk of impinging upon any mounted hardware.
But if IDC ribbon connections are more your style, a set of pin receptacle headers serve to allow you to hot swap your precious Pico between this breakout and the breadboard without breaking a sweat.
The Pico sells for an almost unbelievable price itself (approx. 4 GBP here in the UK!) , and keeping in spirit with that price point, the PICO 2 PI plate sells for barely 50p more over on Tindie, along with a few other neat looking bits from the team at the RedRobotics store.