Kategorie: Linux

What is your history with making?

I’ve always enjoyed building things – I had a big chest of LEGO as a kid, and so did my wife, and now we’ve only expanded it as our children got into model building too!

I’ve been going to BarCamps and hackathons since 2007 and have loved the opportunity to work with other people to put something together in a short space of time. I was even featured on BBC Click as an ‘Inventor’ back in 2009 for building a LEGO Dalek controlled from my phone.

When did you learn about Raspberry Pi?

Pretty early on. My then 12-year-old (now 20!) was one of the judges at the Code Club Pi-hack back in December 2012.

I’ve three active Raspberry Pi [boards] in the house, plus about seven or eight others, connected or embedded in various projects.

How did you start with Code Club?

I started running a programming club in my child’s primary school back in February 2012 – just before Code Club was founded. I approached the head teacher to offer a free lunchtime club for year 4s and he jumped at the idea!

Once the Code Club Scratch projects came out, I switched to using them pretty quickly as they were great fun and the children really enjoyed making their own games.

We’ve now had Code Clubs at Fleetville Junior School for nearly 12 years. I’m still running the year 6 club, even though neither of my kids go there any more! And we also run lunchtime clubs for years 4 and 5 – using Code Club material as well as Minecraft Education, micro:bits and Machine Learning for Kids.

I’ve also started up Code Clubs at work: Tesco Technology supports two clubs – one lunchtime club by our Welwyn office, and one after-school club by our London office.

What are some of your favourite Astro Pi moments?

Getting the kids to guess what the sensors are on my 3D-printed Astro Pi mockup – I run a small program that displays a maze for the gyroscope and accelerometer, and a bar graph for the humidity and temperature sensors. The kids then have to try different inputs to figure out what they are responding to. See the code and some pictures here.

Seeing the actual Astro Pi hardware at Raspberry Pi Big Birthday Bash events and at Richard Hayler’s talk at EMF Camp – and then seeing videos of their twins in the space station.

The enclosure is provided with instructions. These are straightforward, although we will confess to some confusion with wiring in the fan cable. It took four attempts before the ‘ah ha!’ moment when we realised what was intended. The instructions could cover this better. The rest of the installation was painless and thermal pads are included for good contact with the heatsink. Once you have Raspberry Pi inserted, you can add the aluminium cover which gives the overall package a solid, strong feel making it more suitable for environments such as factories or classrooms. The case is held together by screws, adding to the strength of the overall package. You can choose between rubber feet (supplied) or wall-mounting using the built-in screw points.

The case in use

The aluminium cover looks great, but it does mean that the GPIO, PCIE, camera ports and other headers become inaccessible. You are not required to have the cover on to use your Raspberry Pi but it would be great to see alternative covers just as with the official cases. The SD card slot is exposed (which is not the case with many third-party cases) and a nice touch is a cover which can be screwed into place to protect the card from accidental removal. A welcome feature is the combo power light and switch, which links to the new on-board power switch.

Being actively controlled by Raspberry Pi OS means that the fan is silent for the majority of the time and you’ve got to get the CPU nice and busy to get any noise out of the case, which is minimal. As the body is nearly all aluminium, there is plenty of area for soaking up heat, so this would be a great choice for Raspberry Pis under heavy load.

Argon’s build quality is some of the best in Raspberry Pi’s space and this case is no exception. You get the impression that a fall off a desk (normally due to a curious cat) would do it no harm whatsoever. The plastic base has a cheaper feel, but the red accents it provides look the part.

The NEO 5 is another excellent product from Argon that combines value and features into a hard-to-beat package.

Verdict

8/10

A low-cost, good-looking case with excellent resilience and cooling options. A solid choice for any Raspberry Pi project, although some may wish to wait for the next generation of the Argon ONE.

Specs

Cooling: Passive and active, air intake vents

Fan: 30mm PWM

Materials: Aluminium, plastic

No one really uses MS-DOS any more, but the modern, open-source FreeDOS ships with every copy of DOSBox, and you’ve quite probably used that. Most modern DOS developers use DOSBox and its forks for testing, so they can rapidly spot bugs and iterate solutions.

The year 2023 in DOS also saw the release of Damien “Cyningstan” Walker’s stylish Barren Planet, a turn-based, space exploitation-themed strategy game in which rival mining corporations battle for control of resources, with some of the best four-colour CGA graphics we’ve ever seen. Cyningstan has also released a range of tools and libraries to support DOS games development in C, as well as open-sourcing his older games.

Juan J. “Reidrac” Martinez, developed Gold Mine Run! in C and cross-compiled from Linux to DOS, using DJGPP to target 32-bit (i386) DOS. He also open-sourced the game’s code to help other developers.

But you don’t have to use C. Tiny DOS city-builder Demografx was developed in Microsoft QuickBasic 4.5, an IDE released in 1990, which you can run on Raspberry Pi in DOSBox if you can find a copy. Microsoft’s more common QBASIC and GW-BASIC languages are no longer available, but PC-BASIC is a fully-compatible GW-BASIC interpreter you can install on Raspberry Pi, and there’s even a GW-BASIC extension for Visual Studio Code if you want an IDE.

There’s an entire community of developers making wildly distinct games based on ZZT, a 1991 game creation system by Tim Sweeny, now CEO of Epic Games. ZZT spawned a vast living ecosystem of DOS games like WiL’s Galactic Foodtruck Simulator, development tools like KevEdit, and modding tools such as Weave.

There are multiple DOS game jams to encourage would-be developers. In 2023, we saw the DOS COM jam, the DOS Games June Jam, and the DOS Games End of Year Jam.

The DOS renaissance still has a way to go before it catches up to the C64, ZX Spectrum, and Game Boy development scenes, but the sheer range of tools available makes it a very approachable space to experiment in. If you want some inspiration, check out this DOS games we’ve created.

Once people had recovered from the shock of seeing both a power button and a real-time clock on a Raspberry Pi, one of the most commented-on features of the new platform was the small, vertical, 16-way FFC (Flat Flexible Cable) connector on the left-hand side of the board, which exposes a single-lane PCI Express interface.

PCIe of cake

Peripheral Component Interconnect Express (PCI Express or PCIe) is, as the name suggests, a board-level interconnect that allows high-speed data transfer between a processor chip (in our case BCM2712) and external peripherals such as NVMe SSDs, Ethernet cards, or more exotic things such as AI/ML accelerators.

PCIe works by serialising data transfers and sending one bit at a time down a single channel. Higher-capacity PCIe interfaces have more lanes (×2, ×4, ×8, ×16); on Raspberry Pi 5, BCM2712 is connected to our RP1 I/O controller via a ×4 interface. Each lane runs at 5Gbits/s for PCIe 2.0 (the fastest mode that we officially support on Raspberry Pi 5); after coding overhead, this translates into a capacity of 4Gbits/s. Even taking into account other protocol overheads, you’re likely to see ~450MBytes/sec to and from a good NVMe SSD. Pretty fast!

Alongside the data and clock channels, the PCIe specification requires some sideband signals like reset, clock request (which does double duty as a power state signal), and wakeup. Our 16-way connector provides all these signals. We also have two pins that allow us to control board power, and to ensure that an appropriately designed PCIe peripheral is automatically detected by the Raspberry Pi firmware.

Not an M.2

Why didn’t we add an M.2 connector to the Raspberry Pi 5? The M.2 connector is large, relatively expensive, and would require us to provide a 3.3V, 3A power supply. Together, these preclude us offering it in the standard Raspberry Pi form factor.

Using a small, low-cost FFC connector allowed us to provide a PCIe interface without growing the board, or imposing the cost of an M.2 connector and its supporting power-supply circuitry on every Raspberry Pi user.

Specification the first

One thing we did not have ready at the time of the Raspberry Pi 5 launch was a specification for how to build peripherals that attach to the 16-way PCIe connector. The interaction of PCIe peripherals with Raspberry Pi power states and firmware required detailed consideration, and we wanted to make sure we had done extensive testing of our own prototype product to make sure everything was working exactly as expected.

Today, we’re releasing the first revision of that specification: Raspberry Pi Connector for PCIe A 16-way PCIe FFC Connector Specification. Our own M.2 M Key HAT+ is in the final stage of prototyping, and will be launched early next year.

Specification the second

For those of you reading closely, you’ll have noticed that we’re calling our M.2 HAT a “HAT+”. If one new specification wasn’t enough for you, today we’re also releasing a preliminary version of the new Raspberry Pi HAT+ Specification.

The original HAT specification was written back in 2014, so it is now very overdue for an update. A lot has changed since then. The new specification simplifies certain things, including the required EEPROM contents, and pulls everything into one document in the new Raspberry Pi documentation style, along with adding a few new features.

There’s still work to be done on this standard, and our EEPROM utilities haven’t yet been updated to support the generation of the new style of EEPROMs. So this release is very much for people that want to get a feel for how the HAT standard is changing.

We really wanted to get the HAT+ standard right, as it’s likely to be around for as long as the old HAT standard. One of the reasons for the delay in getting the PCIe connector standard published was our sense that PCIe boards that go on top, rather than boards that go beneath, should probably be HAT+ boards. Ours is going to be!

Standards for all!

If you want to discuss them with the community, head over to the Raspberry Pi forums, where you’ll find a dedicated area to talk about HATs, HAT+ and other peripherals.

Watch this space for the new M.2 HAT+, and a final version of the HAT+ standard, which we’ll release alongside it in 2024.

The front of Bullfrog is a smorgasbord of dials with instant appeal to anybody who loves tweaking and the feel of hands-on analogue technology. There are three main sections: VCO, VCF, and VCA/Delay (corresponding to the three elements of sound: pitch, timbre, and amplitude). To the right of this are envelope generators and a Sample&Hold section, while at the top sits a blue cartridge socket. This is where the (included) voicecards slot in. Voicecards patch the internals of Bullfrog and quickly expand the sounds to create a variety of noises. The kit comes with three voicecards: an acid bassline, sampler-loopers (that can record and playback any sound), and a sequencer. There are also three blank voicecards that you can patch yourself by soldering the points together with wires.

To the rear are CV (control voltage) and MIDI (Musical Instrument Digital Interface) ports, phone and audio out, plus power sockets and config buttons. There’s a speaker set into the device itself, or you can use headphones.

Wired for sound

The 77-page manual is where things come to life. It walks you through sound generation, pitch, waveforms, overtones and harmonics, plus virtually every aspect of sound synthesis. Far more than just how to use the equipment, it covers the science behind sound. If there’s any criticism, it’s that it gets a little stuck in the weeds before getting you to patch together the components and start making noises. But this is nitpicking on what is a wonderful educational resource. Girts Ozolins from Erica Synths has made a YouTube video that explains the Bullfrog project that also includes a patching guide.

Taking things further

Bullfrog is more fun with a CV (controlled voltage) keyboard, and the manual mentions an Arturia Keystep or a MIDI keyboard. These enable you to turn the synthesized sounds into notes. It’s also possible to use Raspberry Pi to expand on the music abilities and learning. Either by using Pico to create a CV generator or by attaching a MIDI HAT to Raspberry Pi (see this OSA tutorial). Both of which could add programming aspects to this sound generator.

Erica Synths is using Bullfrog as an educational tool, and to that end has been running workshops using an XL version of the kit that also features an oscilloscope. They are hoping to get it into educational environments around the world.

Verdict

10/10

An innovative educational resource that takes you through sound creation and is a fully working subtractive synthesizer to boot. We loved testing this one out.

Specs

Features: Analogue design, 8-octave voltage controlled oscillator (VCO), voltage controlled amplifier (VCA), voltage controlled waveshapes with pulse width modulation (PWM, voltage controlled amplifier (VCA)

I/O: DIN5 MIDI input, USB connector, CV (controlled voltage), phones out, audio out

Voicecards: cid bassline, sampler-looper, sequencer, 3 × black voicecards are included