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The Raspberry Pi Pico…and a Tiny Plug-In Pi

Yesterday the Raspberry Pi Foundation announced the Raspberry Pi Pico, at the boggling temporary low price of…$4US. It’s definitely a microcontroller on the order of an Arduino rather than the high-end 8GB RPi that might stand in for a complete desktop mobo. And that’s ok by me. The chip at its heart is new: the RP2040, a single-chip microcontroller designed to interface with mainstream Raspberry Pi boards, and lots of other things.


Now, what caught my attention in the page linked above was the list of partner products made by other firms using the same RP2040 chip. Scroll down to the description of the SparkFun MicroMod RP2040 proccesor board. It’s still on preorder, but look close and see what’s there: an edge connector…on a board the size of a quarter! That’s not precisely what I was wishing for in my previous entry, but it’s certainly the right idea.


As I understand it, SparkFun is turning the RPi-wearing-a-hat on its ear, into a hat-wearing-an-RPi. The M.2 interface used in the product is actually a standard developed some years back for use in connecting SSDs to tiny slots on mobos. I knew about M.2, but wouldn’t have assumed you could mount a CPU-add-in board using it. Well, shazam! Done deal.

The RP2040 chip is a little sparse for my tastes. I want something I can run FreePascal/Lazarus on, over a real OS. I don’t see anything in the M.2 spec that would prevent a much more powerful processor board talking to a device (like a keyboard, TV or monitor) across M.2. The big problem with building a high-end RPi into things is keeeping it cool. The Foundation is aware of this, and did a very good job in the $100US Raspberry Pi 400 Pi-in-a-keyboard. (This teardown and review is worth a look if you’re interested in the platform at all. The author of the teardown goosed the board to 2.147 GHz and it didn’t cook itself.)

I fully intend to get an RPi 400, though I’ve been waiting awhile to see if there will soon be an RPi 800 keyboard combo with an 8GB board instead of 4GB. Given the price, well hell, I might as well get the 4GB unit until an 8GB unit appears.

So consider my previous post overruled. It’s already been done. And I for one am going to watch this part of the RPi aftermarket very carefully!


  1. Jim Dodd says:

    I like it when you get excited. I haven’t checked yet but I wonder how this compares with the Raspberry Pi Zero? It’s been a while since I first looked at that.

    Isn’t it funny – the computers keep getting smaller and the monitors keep getting bigger.

    1. Jim Dodd says:

      Well, to answer my question I went here:

      Pico has a built-in ADC but no wireless. Pico doesn’t run an operating system but runs C or Python (not sure of others) programs you load like Arduino.

    2. I’d get excited more if I didn’t have to hide from Teh Viriss so much. But you got it right: The Pi Zero is a real computer and can run an OS. The Pico is a microcontroller, with a lot less compute power. It’s an Arduino competitor. I have an Arduino and I’ve ginned a few things up on it, but I’m not trying to make a profitable product. I’ve thought about creating a Wi-Fi pool thermometer; if I did, I’d develop it (in FreePascal, natch) on a high-end RPi and then implement it on a Pi Zero.

      I’ve been fascinated by the ARM architecture’s slow climb to dominance. If Intel isn’t worried yet, it should be. ARM is a cleaner design with a lot less legacy baggage. I’ll go out on a limb and predict that a full Windows ARM implementation will come out of Microsoft within five years, and it’ll run Intel apps by emulation. If it catches on, software vendors will create ARM editions of their products. That all by itself could be the end of the line for the Intel universe.

  2. The RPi Pico and associated RP2040 MCU are certainly nifty developments. Compared to the huge field of offerings in the microcontroller space they offer a few stand-out features:

    * Multi-core – this is something usually not found in low-end offerings. I suspect more than anything else this will drive an explosion of new users with skill in designing with this challenging tech.

    * PIO peripheral. This is an unusual micro-programmed I/O controller that can do things outside of your normal UART/I2C/SPI protocol. Sort of half-way between a low-end micro and an FPGA. Very flexible.

    * Designed from the ground-up for educational/maker markets, with a focus on Python development. The built-in USB bootloader with UF2 binary support means this is intended for frequent user-friendly code updates, and support for up to 16MB of external flash means it can handle large code and data systems.

    It will be interesting to see where it goes. I don’t suspect it’s going to unseat the existing ARM MCU offerings from ST / TI / MCHP / etc, but it will be a significant challenge in the low-end space occupied by 8-bit Arduino and the like.

  3. Lee Hart says:

    I have to wonder… what do people actually *do* with computers this small? If they’re like flash drives or micro-SD cards, I’m more likely to lose it than use it.

    The “promise” feels a bit like the early days of microcomputers. You could buy or build a cheap little SBC, and the ads shouted, “You can do this! You can do that! You can do everything!” Well, you could… if you wrote all the software, and worked out all the hardware to interface it to something. Now, that was good and bad. You had to do it all yourself; but you LEARNED by doing it yourself.

    These modern micros are great for professional developers. But what do they do for “the rest of us”? What do they do for today’s beginners? Jeff, would you have been able to build Cosmo Klein with one back then (using only what you knew then; not what you know now)?

  4. WILLIAM H MEYER says:

    I’ll just drop this here for your enjoyment:

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