Who Needs a Raspberry Pi Microcontroller Chip? Maybe You

Who Needs a Raspberry Pi Microcontroller Chip? Maybe You(eejournal.com)

20 points by thecatster 4 years ago | 9 comments

whiskers 4 years ago |

Plug: we have designed a range of RP2040 based dev boards for different tasks which make prototyping/evaluating the platform a breeze - and it's an exciting platform with what it offers for the price. The PIO especially is an extremely interesting feature.

- Tiny2040 - a super small USB-C dev board with up to 8MB flash: https://shop.pimoroni.com/products/tiny-2040

- PicoSystem - a handheld gaming console with 240x240 colour IPS display, audio, and classic controls: https://shop.pimoroni.com/products/picosystem

- Keybow2040 - a 16 key macro keypad with per-key RGB lighting: https://shop.pimoroni.com/products/keybow-2040

- Plasma2040 - designed for driving WS2812/APA102 LED strips: https://shop.pimoroni.com/products/plasma-2040

- Interstate 75 - for driving LED matrices like those used in giant outdoor screens: https://shop.pimoroni.com/products/interstate-75

We also have a heap of accessories for the official Raspberry Pi Pico development board: https://shop.pimoroni.com/collections/pico

thecatster 4 years ago | |

I already love a lot of things at Pimoroni, but that Tiny2040 looks great for experimenting with! The wireless pack also seems interesting, might experiment with that concept on a custom board.

gadgetoid 4 years ago |

I haven’t come across an RP2040 I couldn’t overclock to 250+ MHz. Couple that with DMA into the PIO state machines and it smashes through stuff like the weird WS281X timings, HUB75 matrix scanning and even DVI and usually has a whole spare CPU core to actually do something with whatever device you’re driving.

It feels like it sits nicely between regular MCUs and the quirky every-peripheral-is-emulated-in-a-core awesomeness of the Parallax Propeller and - though I’m probably biased by experience and necessity - I love it.

thecatster 4 years ago | |

I honestly loving using it as well, hence the post. I have not always had the best time with the Parallax Propeller (was going to use it for a work project last week but ended up going a different route) but when I have played with it the experience was awesome.

The RP2040 usually just works for me, and the PIO is awesome. I've had a few cool automation projects at home that the RP2040 was the easiest thing to just get up and running with. In the past I would've gone with something in the STM family, but I'm very happy and impressed with the RP2040/Pi Pico.

sylwester 4 years ago |

I am an embedded developer and have used a lot of different microcontrollers in the past and present. The RP2xxx series is a very exciting microcontroller series. Currently only the RP2040 exists, but I expect to see other versions with more ram, integrated flash, maybe a M4 instead of M0+ core.

The truely exciting things about the RP2040 are:

- Market availability

- Low price

- 2 x Cortex M0+ cores

- Possibility to overclock

- Flexible PIO Programmable State Machines with FIFOs

- High GPIO count

- Excellent documentation (!)

- Lots of examples

I think the RP2040 is even totally overpowered / underutilized for most of the tasks I see in most projects.

What I would love to see in the future, is a version with integrated flash (with possibility to expand with external QSPI flash), a cortex M4 core with FPU and the ability to attach PSRAM to expand the usable memory (and map it into the memory map of the RP2xxx).

mrlonglong 4 years ago |

I've been toying with porting a tiny subset of Unix to the Raspberry Pico ever since I bought a pair of these cute little buggers. But memory at 264KB remains an issue. How easy is it to wire up SPI to some external RAM chips maybe on a breadboard?

gadgetoid 4 years ago | |

There’s no support for mapping external memory but you can apparently get creative: https://github.com/yocto-8/yocto-8/blob/main/doc/extmem.md

alar44 4 years ago | |

Yeah you won't even be able to decompress the kernel, you'll need at least a few MB of RAM (and even that would be heroic). Google SPI SRAM, pretty easy to use.

mrlonglong 4 years ago | | |

I think it's totally possible if it's all run from the flash and only used the SRAM for housekeeping. Should be fun !