Tag Archive for BLE

Custom PC, Issue 166

Custom PC Issue 166Readers of my regular Hobby Tech column this month will find a BBC micro:bit-driven tutorial alongside two reviews covering the remarkable Raspberry Pi Zero W microcomputer and the fascinating Delete by Paul Atkinson.

The idea for the tutorial came about while working on a chapter of my upcoming Micro:bit User Guide, and seemed like a perfect fit for the readers of Custom PC Magazine: turning the low-cost yet extremely flexible micro:bit into an addressable USB-connected 5×5 LED matrix and having it display current CPU load in a constantly-updating bar graph. Naturally, the same technique could be used to graph almost anything.

The secret lies in MicroPython’s REPL, an interactive interpreter which can run on the micro:bit and accept commands via the USB serial port. By switching the micro:bit into REPL mode, it can be slaved to another system over USB. The result: the entire program code, written in Python using the serial, time, and psutil libraries, exists purely on the host machine. A quick bit of Blu-tack later, and my monitor was wearing a CPU monitor which worked even when the display was off.

The Pi Zero W, meanwhile, was a device to which I had been looking forward for quite some time. An upgraded version of the original £5 Raspberry Pi Zero microcomputer, the Pi Zero W differs in only one respect: it has a built-in radio module, the same BCM43438 as found on the far larger and more expensive Raspberry Pi 3.

While the addition of the radio module, which offers Bluetooth, Bluetooth Low Energy, and 2.4GHz Wi-FI connectivity, almost doubles the price of the Pi Zero W to £9.60, it’s money well spent. In almost every Pi Zero project I have built, I’ve ended up using a USB OTG adaptor and low-cost USB Wi-Fi dongle to add network connectivity, and having it on-board – even at a slightly higher cost compared to a USB-connected solution – makes life considerably easier.

Finally, Delete. Billed as “a design history of computer vapourware,” Paul Atkinson’s coffee table book is packed with high-quality photographs – and, for the rarer machines, the occasional rescaled JPEG exhibiting unfortunate compression artefacts – covering machines from an upgraded Sinclair QL to a bright yellow IBM that never left the drawing board. Each comes with pages on its history, with interview subjects detailing features and failures alike, and while not all machines were strictly vapourware few are likely to have a place in the average vintage computing collection. In short: if you like old computers you’ll like Delete, which is available now from Amazon and other bookstores under ISBN 978-0857853479.

As always, you can read the whole column and a whole lot more by picking up Custom PC Issue 166 from your nearest supermarket, newsagent, or electronically via Zinio and similar services.

Custom PC, Issue 154

Custom PC Issue 154In this month’s Hobby Tech column I take a good long look at the BBC micro:bit, CubieTech’s latest Cubietruck Plus (Cubieboard 5) single-board computer, and a pack of Top Trumps-inspired playing cards based on vintage computers.

Beginning with the micro:bit, I was lucky enough to be on the receiving end of a press sample when the much-redesigned educational device was finally ready to ship to schools across the UK. Based on the ARM Cortex-M0 microcontroller and boasting integrated Bluetooth Low Energy (BLE), the micro:bit’s main selling point is its excellent support: the web IDE includes four languages suitable for everyone from absolute beginners to experts, there is documentation galore, and the BBC’s TV output includes shows which remind me of the glory days of the BBC Micro and its related programming.

At least, that would be a selling point if the board was actually up for sale. Despite having now mostly fulfilled its promise to ship free micro:bits to all Year Seven pupils in the UK, the BBC has still made no announcement about commercial availability for the educational gadget. Those whose appetites are whetted by the review, then, are best off looking at the CodeBug on which the micro:bit was based, or the new Genuino/Arduino 101 if Bluetooth LE support is a requirement.

The Cubietruck Plus, meanwhile, is an altogether different beast. Kindly supplied by low-power computing specialist New IT, the board is – as the name suggests – a follow-up to CubieTech’s original Cubietruck. The old dual-core processor is long gone, replaced with an Allwinner H8 octa-core chip that blazed through benchmarks with aplomb – and without hitting the boiling-point temperature highs of the rival Raspberry Pi 3.

Sadly, there’s one piece of information that didn’t make it into the review: shortly after the issue went to press, security researchers discovered a debug vulnerability left in Allwinner’s customised Linux kernel which allows any application on the system to gain root permission. Although affecting only selected operating systems, it’s something to be aware of if you’re in the market for an Allwinner-powered SBC.

Finally, the playing cards. Created by start-up 8bitkick following a successful Kickstarter campaign, the deck is nostalgia in a box. The idea is to bring the Top Trumps concept of collectable, trivia-esque comparison gaming to vintage computing: the cards feature everything from the Acorn Atom to the TI-99/4A, plus a joker in the deck in the form of the Raspberry Pi 2 Model B.

The cards are printed with a very high quality finish, but it’s the source of the images that is of most interest: rather than take the pictures itself, 8bitkick has instead scoured the web for images in the public domain or licensed as Creative Commons. It’s no theft, though: while most Creative Commons licenses allow for even commercial reuse if properly attributed, 8bitkick has promised to upload the full deck design to its website for free download and printing.

All this, plus lots of interesting things by people who aren’t me, is only a short trip to the newsagent’s away – or you can stay exactly where you are and grab a digital copy from Zinio or similar services.

Linux User & Developer, Issue 165

Linux User & Developer Issue 165For my regular review in Linux User & Developer this month I had the great pleasure to spend time with the BBC’s first serious hardware project since it teamed up with Acorn in the 80s: the BBC micro:bit.

Originally known as the Micro Bit, the micro:bit is a teeny-tiny microcontroller-based educational programming platform based on the CodeBug. Like the CodeBug, the micro:bit uses a 5×5 LED matrix on its front side as its main method of communicating with the outside world; unlike the CodeBug, the micro:bit includes built-in Bluetooth Low Energy support as well as a gyroscope and magnetic compass, along with the two-button input layout the two share.

With the backing of the BBC, and a major funding drive from Barclay’s which has seen a micro:bit promised to ever Year Seven pupil the UK entirely free of charge, it’s no surprise to see that plenty of companies are involved in the project. At launch, the device boasted no fewer than four programming languages – three provided by Microsoft – in its web-based IDE, along with a neat smartphone app built by Samsung allowing for Bluetooth LE-based interaction and even wireless flashing of programs.

Based on the ARM Cortex-M0 microcontroller (and, oddly, a significantly more powerful Cortex-M0+ which is used exclusively to handle the USB Mass Storage implementation, allowing for mbed-style drag-and-drop flashing without the need to install drivers or a toolchain locally) the micro:bit is impressive, as is the wealth of documentation and supporting materials the BBC has compiled. There’s a catch, mind you: so far, the BBC has not announced commercial availability – meaning we have no idea how much the gadget is going to cost people not included in the generous Barclay’s-funded giveaway programme.

For the full low-down, plus a lot more interesting stuff written by people who aren’t me, head to your local magazine outlet or stay where you are and pick up a digital copy via Zinio or similar services.

Linux User & Developer, Issue 164

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

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.