Custom PC, Issue 227

Custom PC Issue 227This month’s Hobby Tech column dives into the capabilities of the Nvidia Jetson AGX Orin Developer Kit, sees what Retro Games Limited’s TheA500 Mini can do, and finishes with a review of the Amazon Smart Air Quality Monitor for smart home enthusiasts tied into the company’s Alexa ecosystem.

The Nvidia Jetson AGX Orin is a direct successor to the AGX Xavier, which I reviewed back in Issue 190. Like its predecessor, the AGX Orin – or, at least, its Developer Kit incarnation as-reviewed – packs a powerful system-on-module into a compact and actively-cooled casing with reasonable room for expansion, including a full-length PCI Express slot to one side.

Designed for on-device machine learning workloads, the AGX Orin includes a 12-core Arm Cortex-A78AE CPU and an Ampere GPU with 2,048 CUDA cores, 64 Tensor cores, and a pair of NVDLA V2 coprocessors. Add 32GB of LPDDR5 memory and 64GB of eMMC storage expandable via M.2 slot to the base, and you’ve got an absolute beast of a box and one I very much enjoyed putting through its paces.

TheA500 Mini, meanwhile, is also Arm-based – but considerably less powerful. Designed as a follow-up to TheC64 Mini, reviewed in Issue 180, TheA500 Mini swaps Commodore’s popular eight-bit for its Amiga successor. With 25 games pre-loaded – 26 if you download a bonus game and pop it on a USB flash drive – it’s not exactly an exhaustive look at the best the Amiga scene had to offer, but a fun nostalgia trip nevertheless. Special mention must also be given to the bundled peripherals, an optical tank-style two-button mouse and a replica of the CD32 gamepad – both of which can be used on a standard PC as USB peripherals.

Finally, the Amazon Smart Air Quality Monitor is a compact sensor designed to tie in to the company’s Alexa smart home system – to the point where it lacks any form of display of its own, relying entirely on in-app reports and a simple LED on the front which lights up when the air quality drops. Reporting a total of five environmental conditions – particular matter 2.5 (PM2.5), volatile organic compounds (VOCs), temperature, humidity, and, oddly, carbon monoxide (CO) – the sensor is discrete but appears to suffer from a few teething troubles.

All this, and more, can be found in Custom PC Issue 227 at your nearest supermarket or newsagent, online with global delivery, or as a free PDF download on the official website now.

The MagPi, Issue 107

The MagPi Issue 107This month’s issue of The MagPi Magazine includes another of my tutorials for those looking to get started with the MicroPython platform on the Raspberry Pi Pico microcontroller:a temperature sensor, using the analogue-to-digital converter (ADC) built into the RP2040.

Originally written as part of Get Started with MicroPython on Raspberry Pi Pico: The Official Guide, my guide to physical computing on Raspberry Pi’s first-ever microcontroller development board, the tutorial builds in the same way as the other projects in the book – introducing core concepts then building step-by-step from a minimum-viable project up to a fully-functional completed device.

As with other tutorials written for the book, full source code – in MicroPython – is provided, along with a wiring diagram which shows how to wire up a potentiometer using two or three pins and why that makes a difference to how it works. The project can be attacked with no additional hardware, however: the temperature sensor is built into the RP2040 microcontroller on board the Raspberry Pi Pico, and readers are free to skip building the potentiometer circuit if they don’t have the component lying around.

The MagPi Issue 107 is available at now at all good newsagents and supermarkets, online with global delivery, or as a Creative Commons-licensed DRM-free zero-cost PDF download on the official website.

The MagPi, Issue 106

The MagPi Issue 106This month’s issue of The MagPi Magazine includes another of my tutorials for those looking to get started with the MicroPython platform on the Raspberry Pi Pico microcontroller: a Pico-powered burglar alarm driven by one or more passive infrared sensors.

Originally written as part of Get Started with MicroPython on Raspberry Pi Pico: The Official Guide, my guide to physical computing on Raspberry Pi’s first-ever microcontroller development board, the burglar alarm tutorial builds up step-by-step from introducing a single passive infrared motion sensor to interfacing with multiple sensors, printing status reports over the serial console, and triggering a piezoelectric buzzer in place of a real alarm’s rather louder horn.

As with other tutorials written for the book, full source code – in MicroPython – is provided, along with wiring references designed to make it as easy as possible to add the components to a Raspberry Pi Pico installed on a solderless breadboard. There’s scope for further extension, too: adding break-beam sensors, glass-break sensors, or a code pad for disabling and enabling the alarm on-demand.

The MagPi Issue 106 is available at now at all good newsagents and supermarkets, online with global delivery, or as a Creative Commons-licensed DRM-free zero-cost PDF download on the official website.

Custom PC, Issue 149

Custom PC Issue 149This month’s Hobby Tech has just two component parts: a long-term review of the Tenma 60W Digital Soldering Station, and a in-depth guide to building an ultrasonic distance sensor using a Spark Core for a somewhat novel application: shaming me into using my standing desk more.

Looking at the tutorial first, it all stemmed from an office move in which I bought a vast quantity of Ikea furniture. Among it all was a new desk, which for a small extra fee I was able to get with a simple hand-crank mechanism fitted to adjust its height. As I spend the vast majority of my life in front of a computer, I thought a little change like spending some of the day standing instead of sitting would do me the world of good – but, as could be expected, after an initial burst of enthusiasm I found myself using the desk in sitting mode more often than not.

This month’s project was my attempt to rectify that. Using a cheap ultrasonic distance sensor and a Spark Core microcontroller – now known as a Particle Photon, following a major rebranding exercise – I built a device which could track the distance between the surface of the desk and the ceiling and thus report whether it was in sitting or standing mode. When a mode change was detected, it would post a message to Twitter – thus publicly shaming me if I spent too long in sitting mode.

It’s a bit of a daft project, but one which demonstrates some useful techniques: it uses a resistor ladder to lower the 5V output from the ultrasonic sensor to a Spark Core-friendly 3.3V, it shows how a Wi-Fi-connected microcontroller can report readings to a remote system, and even uses If This Then That (IFTTT) to automatically post messages to Twitter based on those readings. As to whether it actually encouraged me to spend more time standing? Not so much.

As the tutorial’s complexity meant taking up a three-page spread, there was only room for one additional feature this month: a two-page long-term review of the Tenma 60W Digital Soldering Station, which I bought some time ago to replace my Maplin-branded variable-output soldering iron. Despite its surprisingly reasonable cost, purchased from the ever-reliable CPC, it’s proven a sturdy tool and is an easy recommendation for anyone looking for an entry-level upgrade from fixed-output irons. It’s also a pleasure to be able to form a long-term opinion on something: all too frequently I review items on a short-term basis, which reveals nothing about their reliability over time. Having been using the Tenma for well over a year now, though, I can personally guarantee its longevity.

All this, plus a variety of interesting things written by people who aren’t me, can be yours at your local newsagent, supermarket, or electronically via Zinio and similar digital distribution services.