back to article Building the Internet of Things with Raspberry Pi et al, DIY-style

The Internet of Things (IoT) is all the rage at the moment, with dozens of manufacturers throwing out kit like remote-control lightbulbs, weather stations, thermostats and plenty more. Some of those are great products and some of them are also-rans. Quite a lot, it turns out, are actually simple enough that you could probably …

  1. Richard 12 Silver badge

    Unconvinced that the 240V PowerTail is adequate

    It's simply a 120V version with different relay and MOVs.

    While the circuit and component selection look fairly sound, the PCB design looks extra-low-voltage, and may not be suitable for EU mains voltage supplies. It's quite hard to get mains voltage thru-hole PCB design right.

    Can't be sure without a sample, and there's no hint as to the backside of the board on any of their published docs, however the topside creepage looks like ~1.5mm, when the standard requires at least 2.4mm*. You don't run tracks down the isolation gap - those pins are that far apart for a reason - and Protective Earth looks really close to LN.

    I don't think El Reg should mention any mains voltage kits for the EU unless they've got good reason (CE mark etc) to believe that it complies with the basic safety regs in the EU. These set of devices look like they meet most US codes, but not EU ones.

    * Assuming 'normal' PCB material and that it's not hermetically sealed.

    1. Nigel Whitfield.

      Re: Unconvinced that the 240V PowerTail is adequate

      Thanks; good points, and I shall bear them in mind next time I cover this topic.

  2. DCFusor

    Notihg in the review about the actual internet

    Which might be good, actually. Putting your home on the actual internet is fraught with issues. Either you give way too much data out to some central site (Google Nest kind of thing) and become the product, post data mining, or you establish your own fixed IP so you can talk to your home remotely. And in either case, you're likely subject to any hacker with a backdoor into either, which are numerous.

    I found in my own Lan of things project that it was obvious from things like barometers, water line temp sensors and so on, just when I was home, whether I washed my hands after using the loo - and so on, far to much personal info, and a big red flag for "nothing's going on, he's not home, come burgle him".

    Being a homesteader in the US I do find it useful to be able to monitor and control my campus, and these days ethernet (TCP/IP and/or UDP) is the way vs the little power-line comm of years past. But no way am I exposing all that to the internet at large purposely. It's as firewalled as can be, and at least has a bit of security by obscurity even if you should manage to get in. Here, in most places one has to pay "rent" in some fashion to have a domain, or even just a fixed IP address from your ISP, so I save that as well.

    More here:

    While as I say, it's pretty specific to my needs and will never truly be "done", perhaps this will help some people with some ideas and some details - and the price is right (free).

    1. Chemist

      Re: Notihg in the review about the actual internet

      "you establish your own fixed IP so you can talk to your home remotely. And in either case, you're likely subject to any hacker with a backdoor into either, which are numerous."

      There is another option I use when I'm feeling paranoid. I have a few PIC microcontrollers, run by a server program on my Linux fileserver. I've set up a system whereby a cron job regularly reads a text file on my website and sets-up the PICs accordingly. A futher cron job reads any inputs from the PICs and writes out to the website. This being a totally passive system means I don't have to ssh in to home just to change a few things.

      1. Anonymous Coward
        Anonymous Coward

        Re: Notihg in the review about the actual internet

        Your life must be really straightforward if you worry about google knowing how many leafs you have earned this month. Me, I have far more concerning issues, like if there is enough milk in the fridge.

        As for IOT, I have Nest and LIFX bulbs, and they are excellent products, genuinely useful (my lifx bulbs always come on at dusk all year round thanks to a IFTT script) and genuinely money saving ( Nest is on track to pay for itself in its 2nd year in noticeable heating bill reductions).

        I'm not however going to be getting a internet connected fridge however

        1. Anonymous Coward
          Anonymous Coward

          Re: Notihg in the review about the actual internet

          > Me, I have far more concerning issues, like if there is enough milk in the fridge.

          My more concerning issue is not whether there is enough milk in the fridge, but how long it's been there and should I open the door or should I just buy a new fridge.

    2. Nigel Whitfield.

      Re: Notihg in the review about the actual internet

      Well, as I say, the book does raise the issue of security at various stages, so even novice users will be aware of some of the potential risks.

      It could probably go further, but how far do you go before it becomes an unwieldy book that still probably wouldn't cover everything? A few years back, I wouldn't have been surprised to see books like this barely even addressing it.

  3. DCFusor

    Nothing in the review about the Actual Internet

    Hey, people, read my title! The review does not mention one thing about how you'd actually put any of this on the internet itself, though it's in the book title. Talk about short attention span issues.

    I'm no security expert, though I've been reading them on the inet for decades, and yes, have had my home network pen tested now and again. I was the one who brought up security - nothing in the review about that either. Hence the fail icon.

    I was a systems, including embedded, designer in my career as an engineer, and FWIW, I happen to like PICs myself - they often saved our customers quite a chunk of change on products made in volume. I use them here. They fer sure had the very best built in IO hardware, and "just worked" though others are now catching on.

    Why then, did I choose Raspi and Arduino Uno for my own stuff? I'm tired of laying out boards, writing basic drivers and opsys, and these are both so cheap I can afford to keep hot spares for *everything* - even stuff expected to fail no sooner than a decade. Will your pic chip still be shipping then? Or the Intel Nuc's I favor for x86 use, mostly? Will x86 even still be around? By then I'll be too old for a do-over.

    Seems likely that due to wide uptake, the web will be around, or at least html, TCP/IP, and I'll have spares for the rest. And that's the point here - this is meant to live quite a long time (as long as I live, or care). Thus, while neither of my choices for the master per building or the slaves that do the sensing are ideal from a systems design point of view in say mips per watt - or dollar - they are ideal in that there's a hot spare literally on the site, within feet of everything. And oh yeah - the pi's can run the arduino dev IDE...and their own.

    I'm perhaps lucky that there is in fact no need to control anything remotely at all - I am almost always home anyway. I actually don't see much value other than "look, shiny, buy my stuff" in that ability, and do see (as a previous Reg article mentions) some serious security issues just so one could turn up one's heat during the drive home to save some pennies. I don't see that as worth it with the current state of hacking for troll reasons, much less APT types. Just my rarely humble opinion of course. And I could do this - I do have a website linked above (as well as a somewhat interesting youtube channel as dcfusor). But I choose not to for the reasons mentioned. Regular automation is fine for me, and I have unusual needs due to homesteading rather than say, living in a conventional apartment or home. A lot of things here were done with much more manual input than the average guy does - he substitutes having a job and money (the oldest form of magic - "let it be done", now working for $) for that kind of thing, I don't. So in this case, I'm literally working for myself, building things that save my own labor down the road so I have more time for more fun of other sorts.

    1. Nigel Whitfield.

      Re: Nothing in the review about the Actual Internet

      The review does mention that the book covers this sort of topic, and web services such as Xively. But the article is above all a review of the book, not an instruction manual itself.

  4. John Styles

    'Internet' is now the collective noun for things e.g. pride of lions, colony of badgers, internet of things

    1. Robert Helpmann??

      Collective Nouns

      'Internet' is now the collective noun for things

      Yes! Like a cluster of computers, a tangle of cables, a bank an elephant of RAM or a spaghetti of code.

      1. Eddy Ito

        Re: Collective Nouns

        Can you measure a spaghetti of code and if you can would you measure it in linguini?

      2. Anonymous Coward
        Anonymous Coward

        Re: Collective Nouns

        > a spaghetti of code.

        Have you been looking at my Github again?

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