rp2040

153 Articles

Compose Any Song With Twelve Buttons

March 29, 2023 by 15 Comments

Limitations placed on any creative process often paradoxically create an environment in which creativity flourishes. A simple overview of modern pop, rock, or country music illustrates this principle quite readily. A bulk of these songs are built around a very small subset of music theory, often varying no more than the key or the lyrics. Somehow, almost all modern popular music exists within this tiny realm. [DeckerEgo] may have had this idea in mind when he created this tiny MIDI device which allows the creation of complex musical scores using a keyboard with only 12 buttons.

The instrument is based around the Adafruit MacroPad, which is itself built on the RP2040 chip. As a MIDI device, it needs to be connected to a computer running software which can support MIDI instruments, but once its assembled and given its firmware, it’s ready to rock. A musician can select one of any number of musical scales to operate within, and the 12 keys on the pad are mapped to the 12 chromatic notes within that scale. It can also be used to generate drum tracks or other backing tracks to loop before being used to create melodies as well.

[DeckerEgo] took a bit of inspiration from an even simpler macro pad we featured before which is based around the idea that a shockingly high number of songs use the same four chords. His macro pad includes creation of chord progressions as well, but expands on that idea to make more complete compositions possible. And, for those looking to build their own or expand on this project, he has also made all of the source code available on his GitHub page.

Continue reading “Compose Any Song With Twelve Buttons” →

Working Artificial Horizon Built Into A Single LEGO Brick

March 20, 2023 by 16 Comments

Back in the day, LEGO spaceship sets used to come with these little wedge blocks painted with fake gauges on them. [James “Ancient” Brown] decided that wasn’t good enough. Thus, he took everything he needed for a functional artificial horizon, and stuffed it inside a single LEGO brick. Yes, it’s real, and it’s spectacular.

We featured [James’] electronics-infused bricks some time ago when they first hit the Internet. The basic story is that he managed to cram an OLED screen and an RP2040 into a silicone mold for a LEGO-compatible brick. His first iterations stunned the world, as they ran pretty monochrome animations that brought life to formerly-inanimate chunk of plastic.

Since then, [James] has been busy. He’s managed to squeeze an accelerometer into the brick form factor as well. That allowed him to build a LEGO piece which displays an impressively-smooth artificial horizon display, as you might find in an aircraft. He demonstrates this by putting the instrument on a LEGO craft and zooming it around the room. All the while, the artificial horizon accurately tracks the motions of the craft.

It’s an impressive build, and something we’d love to see included in future LEGO vehicles…even if they’re just 3D renders. Continue reading “Working Artificial Horizon Built Into A Single LEGO Brick” →

A Pi Pico soldered onto a custom breakout PCB, with an SD card connected to it using prototyping wires

RP2040 Runs Linux Through RISC-V Emulation

March 19, 2023 by 27 Comments

We’re used to running Linux on CPUs where it belongs, and the consensus is that RP2040 just isn’t up for the task – no memory controller, and nowhere near enough RAM, to boot. At least, that’s what you might believe until you see [tvlad1234]’s Linux-on-RP2040 project, reminding us there’s more than one way to boot Linux on a CPU like this! Just like with the “Linux on AVR” project in 2012 that emulated an ARM processor, the pico-rv32ima project emulates a RISC-V core – keeping up with the times.

Initially, the aforementioned “Linux on AVR through ARM” project was picked as a base – then, a newer development, [cnlohr]’s RISC-V emulator, presented itself and was too good to pass up on. Lack of RAM was fully negated by adding an SD card into the equation – coupled with a small caching layer, this is a crucial part for the project’s not-so-secret sauce. A fair amount of debugging and optimization later, [tvlad1234] got Linux to run, achieving boot times in 10-15 minutes’ ballpark – considering the emulation layer’s presence, this is no mean feat.

At this point, the boot process stalls as you enter a login shell. If Linux on RP2040 is within your area of interest, feel free to pick up the effort from here, as the project is fully open-source – you only need a Pi Pico board and a throwaway SD card! Now, if pairing a RP2040 with some classic software is your definition of an evening well-spent, you can’t go wrong with DOOM! However, if you’d rather play with something else *nix-like, we’ve seen someone port Fuzix onto the RP2040 before.

DOOM Ported To A Single LEGO Brick

March 18, 2023 by 18 Comments

By now you’ve all seen the tiny LEGO brick with a working screen in it. The work of one [James “Ancient” Brown], it was truly a masterpiece of miniaturization and creativity. Since then, [James] hasn’t stopped innovating. Now, he’s demoing a playable version of DOOM running on a single plastic brick.

We’ve covered the construction of these astounding screen bricks before. Long story short, [James] designed a tiny PCB that hosts an RP2040 microcontroller which is then hooked up to a tiny OLED screen. The components are placed in a silicone mold, which is then filled with transparent resin to form the brick. The screen is then powered via contacts in the bottom, much like older-style LEGO motors.

Early experiments involved running various graphics to emulate a spaceship dashboard, but [James] has now gone much further. He’s implemented RP2040-doom to run the game. It uses tilt controls thanks to an accelerometer, combined with capacitive touch controls for shooting. The monochrome OLED is driven very fast with a special library of [James’] own creation to create three levels of grayscale to make the game actually visible and (just barely) playable.

It’s a hack, of course, and the controls are far from perfect. Nobody’s speed-running E1M1 on [James’s] LEGO brick, to be sure. Perchance. With that said, it’s still a glorious piece of work nonetheless. Just imagine, sitting with friends, and announcing you’re going to play some DOOM — only to pluck a piece of LEGO out of your pocket and start blasting away at demons.

Just because [James] doesn’t know when to quit, we’re going to lay down the gauntlet. Let’s get network play happening on these things, yeah?
Continue reading “DOOM Ported To A Single LEGO Brick” →

Cornell Updates Their MCU Course For The RP2040

March 10, 2023 by 16 Comments

The School of Electrical and Computer Engineering at Cornell University has made [Bruce Land]’s lectures and materials for the Designing with Microcontrollers (ECE 4760) course available for many years. But recently [Bruce], who semi-retired in 2020, and the new lecturer [Hunter Adams] have reworked the course and labs to use the Raspberry Pi Pico. You can see the introductory lecture of the reworked class below.

Not only are the videos available online, but the class’s GitHub repository hosts extensive and well-documented examples, lecture notes, and helpful links. If you want to get started with RP2040 programming, or just want to dig deeper into a particular technique, this is a great place to start.

From what we can tell, this is the third overhaul of the class this century. Back in 2012 the course was using the ATmega1284 AVR microcontroller, and in 2015 it switched to the Microstick II using a Microchip PIC32MX. Not only were these lecture series also available free online, but each has been maintained as reference after being replaced. One common thread with all of these platforms is their low cost of entry. Assuming you already have a computer, setting up the hardware and software development environment for these modules costs less than the price of a pizza dinner, a fact no doubt appreciated by the ECE department’s budget director.

We’ve covered this course before back in 2015 when it first changed. Another free online course on embedded system design is from [Prof James Conrad] at UNC Charlotte, based on the Renasas RX63N microcontroller — the UNC Charlotte team drove development of the autonomous vehicle project we covered back in 2009. If you know of other online embedded systems classes, let us know in the comments below.

Continue reading “Cornell Updates Their MCU Course For The RP2040” →

A Pi Pico plugged into a breadboard, with jumpre wires going away from its pins to an SPI flashing clip, that's in turn clipped onto an SPI flash chip on a BeagleBone board

Programming SPI Flash Chips? Use Your Pico!

March 6, 2023 by 10 Comments

At this point, a Pi Pico is equivalent to a bag full of programmers and debugging accessories. For instance, when you want to program an SPI flash chip, do you use one of those wonky CH341 dongles, or perhaps, even a full-on Raspberry Pi with a Linux OS? If so, it might be time to set those two aside – any RP2040 board can do this now. This is thanks to work of [stacksmashing] who implemented serprog protocol for the RP2040, letting us use a Pi Pico with stock flashrom for all our SPI flash chip needs.

After flashing the code to your RP2040 board, all you need to do is to wire your flash chip to the right pins, and then use the serprog programmer type in your flashrom commandline – instructions are available on GitHub along with the code, as you’d expect. Don’t feel like installing flashrom, or perhaps you happen to run Windows and need a flasher in a pinch? [stacksmashing] has a WebSerial-based SPI flasher tool for you, too, and shows it off with a fancy all-the-pinouts board of his own making.

This kind of tool is indispensable – you don’t need to mod one of these CH341 programmers to fix the bonkers 5 V default IO, or keep an entire Linux computer handy when you likely already have one at your fingertips. All in all, yay for one more RP2040 trick up our sleeve – this SPI flashing helper joins an assortment of applets for SWD, JTAG, UART, I2C and CAN, and in a pinch, your Pi Pico will also work as a digital and analog logic analyzer or an FPGA playground.

 

Showing balloon rising up, not too far from the ground, with one of the FOSDEM buildings and sky in the background

FOSDEM Sees Surprise Pico Balloon Event

March 4, 2023 by 23 Comments

At any vaguely-related conferences, groups of hackers sometimes come together to create an impact, and sometimes that impact is swinging something into an airspace of a neighboring country. [deadprogram] tells us that such a thing happened at FOSDEM, where a small group of hackers came together (Nitter) to assemble, program and launch a pico balloon they named TinyGlobo 1, which then flew all the way to France!

This balloon is built around a RP2040, and the firmware is written in TinyGo, a version of Go language for microcontroller use. As is fitting for a hacker group, both the hardware and software are open source. Don’t expect custom PCBs though, as it’s a thoroughly protoboarded build. But a few off-the-shelf modules will get you the same hardware that just flew a 400km route! For build experiences, there’s also a few tweets from the people involved, and a launch video, also embedded below.

This reminds us of the Supercon 2022 balloon story — darn copycats! If you’re interested in the more Earthly details of this year’s FOSDEM open source development conference, check out our recent coverage.