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.

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 Рwhich required me to get out the microscope in order to capture its markings Рhas 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.