Nearly a decade after debuting its first $35 single-board computer, the Raspberry Pi Foundation is launching a new Raspberry Pi Pico that sells for just $4. It’s so small and so cheap that you get one free when you buy a copy of the February 2021 edition of HackSpace magazine.
But the Raspberry Pi Pico isn’t a full-fledged, Linux-friendly general-purpose desktop computer like other Raspberry Pi devices. Instead it’s a small board built around Raspberry Pi’s new RP2040 microcontroller which is a low-power chip designed for low-latency I/O, analog input, and lightweight software.
In a nutshell, it’s designed for applications that need to interact with sensors, motors, lights, or other hardware but which don’t require a complex general-purpose operating system like Linux, which might just slow things down. Of course, the Pico can be paired with a Raspberry Pi or other computer for more complex actions. And the Raspberry Pi Foundation is also making the RP2040 microcontroller available to third-party hardware makers, so there are a number of new boards featuring the chip from companies including Adafruit, Arduino, Pimoroni, and Sparkfun.
Among other things, the RP2040 chip features a 133 MHz dual-core ARM Cortex-M0+ processor, 264KB of on-chip memory, support for up to 16MB of off-chip flash memory, a DMA controller, 30 GPIO pins (including 4 that support analog inputs), a USB 1.1 controller, and UART, SPI, and I2C controllers (2 each).
The Raspberry Pi Pico board pairs the microcontroller with 2MB of flash memory, 26 exposed GPIO pin, a USB port, LED light, and a power supply chip (with support for 1.8 to 5.5V, enabling support for power sources including AA or lithium-ion batteries).
Raspberry Pi says it’s also making a C software development kit, GCC-based toolchain, and Visual Studio Code integration available as well as detailed documentation.
And if you’d rather pick up an RP2040 board with different features, third-party boards offer features including more flash storage, lights, input and output features, microphones, wireless modules, and motion sensors including gyroscopes, accelerometers, and compass.
Most of those third-party boards should be available for pre-order in the coming weeks, and you can read more about them (and find links) at the Raspberry Pi Blog.
Someone needs to make a board with a RP2040 and a Ethernet RJ45 MagJack on it, then run a TCP/IP stack like lwIP or uIPv6 on one of the M0 cores.
Arduino is making a board with the RP2040 plus the versatile u-blox NINA WiFi and Bluetooth module:
https://blog.arduino.cc/2021/01/20/welcome-raspberry-pi-to-the-world-of-microcontrollers/
It’s too bad they couldn’t break-out all 30 IO pins that the chip supports, I guess fitting 26 pins on the board was a space/size thing.
This is a phenomenal value compared to things like Arduinos/Pro-Micro/etc (project boards that run on Atmega chips), because this board offers a decent amount of IO pins, and the screw-holes are a really nice plus.
I’ve often had to mount my Pro Micro boards using a hot glue-gun, or JB Weld.
This microcontroller is different to most as it does not use on-die flash memory. Instead it relies on a separate flash memory chip. It does have a relatively large amount of on-die SRAM. It’s also a dual-core microcontroller which makes it rare. The peripherals are also quite different to other microcontrollers… some improvements, some deficiencies.
I’m not sure if I like executing from external flash (or copying it to internal sram and executing from there). I also don’t like their timer peripheral. Until I have a project that can’t be solved with my mainstream microcontrollers, I probably will not get one. Furthermore, I think that learning about mainstream microcontrollers is a better use of time as they are commonly used in existing products and projects (github).
I haven’t read the datasheet yet, but based on the design of this board, I’m assuming it also uses an external crystal oscillator (I’m guessing that’s what the 3225-size component is)
Unfortunately there’s too many complex external components for this chip to make it an attractive chip for any of my project PCBs. I guess you’d really need to want that 2nd core.
I agree. Seeeduino Xiao also has castellated holes and is 1/3 the size of the RP2040… that would be much easier to include on a project. For a custom board nothing beats the size of a standalone microcontroller IC. It would have been interesting if the RP2040 had perforations so that half the board IO could be snapped off. I like the Xiao because it leaves lots of room for other components on a breadboard.