BCM2837

Custom PC, Issue 153

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Custom PC Issue 153My regular Hobby Tech column celebrates its third year this month, and I’d like to think it does so in style. As well as a two-page review of the Raspberry Pi 3, the column details how to build a Raspberry Pi Zero-based energy usage graph into a cheap box frame and interviews Raspberry Pi Foundation director of hardware James Adams about his designs and inspiration.

First, the Pi 3. I’ve previously written about the board in a cover feature for The MagPi and in Linux User & Developer, so there should be no major surprises in this review – beyond a focus more on the hobbyist community’s desires and concerns, given the title of the column. The interview, though, is all-new: a small, separate extract of my interview was published in The MagPi’s Raspberry Pi 3 launch issue, but the material used in Hobby Tech is fresh – including detailed information on just how that Wi-Fi and Bluetooth radio module talks to the new BCM2837 SoC and the challenges of conformance testing something that has an intentional radio emitter inside.

The build was a project I worked on after picking up a cheap electricity and gas monitor for my house. While the website works well for viewing live usage and historical graphs, I wanted something that wouldn’t look out of place in the living room and hopefully remind everyone to turn things off when they leave! A cheap Raspberry Pi Zero was the perfect platform, and combine with a Pimoroni Unicorn HAT fits snugly in the back of a wooden box frame. Some paper on the front diffuses the LEDs to prevent glare and make it look less like a hack and more like a piece of furniture – though with the consequence that the photos look a little washed out compared to the bright, colourful display in the flesh – and everything else is a software concern.

All this, and interesting things written by people who aren’t me, is available from your local supermarket, newsagent, or electronically via Zinio and similar services.

Linux User & Developer, Issue 164

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Linux User & Developer Issue 164My review for this month’s Linux User & Developer magazine is of a device I’ve been playing with for a while now: the Raspberry Pi 3, the first single-board computer from the Raspberry Pi Foundation to include a 64-bit CPU and integrated radio chip.

Following my cover feature for The MagPi magazine, the Raspberry Pi 3 once again graces a magazine cover – and well it should. The switch from ARM Cortex-A7 to ARM Cortex-A53 processors cores in the new Broadcom BCM2837 system-on-chip (SoC) brings with it a considerable performance boost over the Raspberry Pi 2, which itself left the original single-core Raspberry Pi in the dust.

That’s even before discussing the integrated wireless connectivity. Boasting 2.4GHz Wi-Fi, Bluetooth 4.1, and Bluetooth Low Energy, the Raspberry Pi 3 certainly ticks a lot of boxes on the connectivity front – even if the integrated Ethernet port still communicates with the SoC through a shared single USB channel. Best of all, the board is entirely compatible with accessories and software written for earlier models – going all the way back to the early raft of add-ons for the original Raspberry Pi.

One discovery that cropped up between the MagPi launch feature and this review, though, was heat generation: testing under my thermal camera, published on imgur for the curious, revealed that the Raspberry Pi 3 gets considerably hotter than its predecessors – over 100°C under CPU load. This leads to a couple of issues: potential burns if you poke the chip and thermal throttling which dramatically harms performance if the Pi 3 is installed in a case. Coupled with even harsher throttling – from 1.2GHz to just 600MHz – when used with marginal power supplies or low-quality micro-USB cables, there are caveats aplenty.

For the full low-down, pick up a copy of Linux User & Developer Issue 164 from your nearest supermarket, newsagent, or electronically via services such as Zinio.

The MagPi, Issue 43

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The MagPi Issue 43It’s a special week for the Raspberry Pi Foundation: it’s celebrating its fourth birthday with the launch of the new Raspberry Pi 3. It’s a special day for me, too: the latest MagPi magazine boasts a total of thirteen pages of my content, including the cover splash: a detailed and thorough look at the new model.

Boasting on-board Wi-Fi (a community request since the original model launched four years ago), Bluetooth 4.1, Bluetooth Low Energy, and a faster 64-bit ARMv8 processor, the new Pi 3 is a bit of a beast. My cover feature for the magazine begins with a look at those behind it with a double-page spread featuring interviews with project co-founder Eben Upton and the Foundation’s director of hardware and the man responsible for circuit design James Adams – and a massive thank-you to both for sparing the time to talk to me at one of their busiest ever periods!

The feature then moves on to a look a the board itself, with a hero photo of the board spread across another two pages. Each major feature of the board, from the shiny new 64-bit BCM2837 system-on-chip (SoC) processor to the BCM43438 radio module – which required me to get out the microscope in order to capture its markings – has a call-out with close-up photography and an explanation of how it has changed since the Raspberry Pi 2.

Next up is a benchmark spread, which required me to come up with a detailed suite of tests. After some experimentation, I settled on a selection of classic benchmarks – SysBench CPU in single- and multi-threaded modes, Linpack with and without NEON support, Whetstone, Dhrystone, SysBench memory read and write, Ethernet throughput, Quake III Arena timedemo performance, and power draw at load and idle. As an added bonus, I also came up with a way of measuring general-purpose input-output (GPIO) performance under Python, writing a simple benchmark to toggle a pin on and off as quickly as possible and measuring the speed with a frequency counter connected to the GPIO header.

The next double-page spread looks at helping the reader get started with the new device. I walk readers through modifying an existing Raspbian installation to boot on the Pi 3 by editing config.txt, setting up the Wi-Fi module, enabling true OpenGL acceleration on the graphics processor, and how to write programs to get the best performance on the Pi 3. Sadly, I was unable to explain how to use the Bluetooth 4.1 and Bluetooth Low Energy features, as software support was not available at the time of writing.

The spread then ends with a look at five things you could do with a Pi 3 in order to take advantage of the new features and boosted performance. My work for the magazine continues, though, with a review of the Proster VC99 multimeter and Pimoroni pHAT DAC, before coming to a close with a one-page news piece regarding the production status of the popular Raspberry Pi Zero – helping to explain why it has been so difficult to get hold of and settling concerns that it may be bumped to the back of the production queue now the Pi 3 is out.

All 13 pages of my content, and plenty of other stuff by people who aren’t me, are available from your nearest supermarket or newsagent, or as a free PDF download under a Creative Commons licence from The MagPi’s official website.

Linux User & Developer, Issue 162

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Linux User & Developer Issue 162In addition to my regular four-page news spread, this month’s Linux User & Developer features a review of a maker-oriented computer-on-module (COM): the LeMaker Guitar.

The Guitar comes from the same company that brought us the Banana Pro, but while LeMaker has ditched its fruit-themed product nomenclature it’s still drawing inspiration from the same source: the Guitar the Chinese company’s equivalent to the Raspberry Pi Compute Module, based on the same SODIMM-layout module design and featuring a bundled break-out board to make the device’s features more accessible to hobbyists.

Where it improves on the Compute Module’s design is in its specifications: an Action system-on-chip (SoC) processor proves considerably more capable than the ageing BCM2835 of the Raspberry Pi Compute Module, there’s more RAM, and it even has Wi-Fi connectivity – though this, sadly, is based on a module attached to the break-out board, meaning that it’s not something you’ll have available should you decide to build your own circuit with the Guitar module at its heart.

When I reviewed the device, I was particularly impressed with the performance for the price – especially given that the Compute Module is considerably more expensive than the Guitar. In the time since the review, though, retailers have significantly discounted the Compute Module ahead of the planned launch of a 64-bit, 1.2GHz Compute Module 3 later this year based on the same BCM2837 SoC as the newly-launched Raspberry Pi 3. If you’re not in a rush, in other words, it may be worth seeing how much the Compute Module 3 costs before designing anything around the Guitar.

The full review, along with my four-page news spread, can be found gracing the shelves of your nearest supermarket, newsagent, or as a series of zeroes and ones on digital distribution services including Zinio.