Go Back Quick Help

Fullscreen

SILICON CHIP www.siliconchip.com.au Publisher Leo Simpson, B.Bus., FAICD Editor Nicholas Vinen Editorial Viewpoint Got a project idea? There’ll be a badly designed app for that! Derby Street, Silverwater, NSW 2148. In thinking up ideas for projects to publish in Silicon Chip, we have a lot of hurdles to overcome and they seem to be multiplying. Increasingly, we face the challenge of coming up with designs that aren’t already available commercially (eg, from China) for less than the retail cost of the parts. We also have to consider the availability of smart phone apps which purport to do a similar job. But while there is often an “app for that”, it usually turns out to be a bit of a joke. For example, while working on the Earthquake Early Warning project published this month, we decided to try out a few earthquake alert apps first. One claimed to provide “earthquake early warning” but seems to rely mostly on alerts from the USGS Earthquake Notification Service which states: “Information for earthquakes in the U.S. is generally available within 5 minutes; information for earthquakes elsewhere in the World is generally available within 30 minutes”. Hmm. Getting a message 30 minutes after a quake does seem a little pointless! Now, the app does claim that it uses your phone and others running the same app in the general area to directly detect and warn of earthquakes but since there haven’t been any earthquakes in our area in the last couple of months, we have no way of evaluating its true effectiveness. What if nobody nearby is running the app? How do we know their earthquake detection software really works? And this is not an isolated case. For example, we’ve long thought that pretty much all “sound meter” apps are generally useless since the microphone in your phone doesn’t have enough dynamic range and isn’t calibrated. And audio oscillator apps cannot be guaranteed to generate the frequencies you might select. You might hear a tone but it might be far removed from the frequency it purports to be. This was driven home for me while watching an episode of the TV show “Top Gear” a few years ago where the host as the time, Jeremy Clarkson, attempted to measure the noise levels of three different cars using his iPhone. He got pretty much the same reading in each case (within 1dB); possibly because the microphone was being overloaded by the noise. And the app “sort of” works, while the microphone sensitivity is an unknown and therefore any measurements may have very doubtful accuracy. Maybe this was a stunt; surely a TV show with a multi-million dollar budget could afford a proper sound level meter? But I wonder how many users of this sort of app realise its limitations? Light meter apps also must be suspect. While seemingly useful, we have to wonder just how accurate they are; presumably they sample the light using the phone’s camera and its accuracy will vary from model to model. And the apps rarely provide any information as to the reliability or precision of their readings. They could be spot on or way off. Unless you compare them directly to a calibrated instrument, how would you know? Having said all that, some apps definitely are handy. For example, we’ve published circuits in the past to generate white noise, water sounds and so on but now there are free “white noise” apps which make such projects obsolete. And that’s just one example that comes to mind. So when you see a project in the magazine, know that we’ve considered all the above. And before you rely on any app, make sure you check to ensure that it can deliver what it promises. ISSN 1030-2662 Recommended & maximum price only. Nicholas Vinen Technical Editor John Clarke, B.E.(Elec.) Technical Staff Ross Tester Jim Rowe, B.A., B.Sc Bao Smith, B.Sc Art Director & Production Manager Ross Tester Reader Services Ann Morris Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Dave Thompson David Maddison B.App.Sc. (Hons 1), PhD, Grad.Dip.Entr.Innov. Geoff Graham Associate Professor Graham Parslow Ian Batty Cartoonist Brendan Akhurst SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490. All material is copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Subscription rates: $105.00 per year in Australia. For overseas rates, see our website or the subscriptions page in this issue. Editorial office: Unit 1 (up ramp), 234 Harbord Rd, Brookvale, NSW 2100. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9939 3295. E-mail: silicon<at>siliconchip.com.au Printing and Distribution: 4    Silicon Chip Celebrating 30 Years siliconchip.com.au