LoRaWAN And Raspberry Pi Compute Module For A Remote Display

February 8, 2017 by Jenny List 5 Comments

We see a lot of Raspberry Pi projects on these pages featuring all variants of the little board from Cambridge, but with one notable exception. Surprisingly few of them have featured its industrial embedded cousin, the Raspberry Pi Compute Module. The Pi-on-a-SODIMM form factor is a neat idea, but we are guessing that the high price of the development board relative to that of a Model B or a Pi Zero has pushed most people in our community towards the latter choice.

[Andrew Back] has put up a straightforward demonstration project on the RS DesignSpark site that provides an introduction to the Compute Module 3, using it to run a remotely operated display. In addition it uses an RN2483 LoRaWan radio module and The Things Network for communication, which makes it worth a look even if the Compute Module wasn’t of interest. Continue reading “LoRaWAN And Raspberry Pi Compute Module For A Remote Display” →

How Commercial Printed Circuit Boards Are Made

February 8, 2017 by Jenny List 30 Comments

Most of us who have dabbled a little in electronics will have made our own printed circuit boards at some point. We’ll have rubbed on sticky transfers, laser-printed onto acetate, covered our clothing with ferric chloride stains, and applied ourselves to the many complex and tricky processes involved. And after all that, there’s a chance we’ll have ended up with boards that were over or under-etched, and had faults. For many the arrival of affordable online small-run professional PCB production from those mostly-overseas suppliers has been a step-change to our electronic construction abilities.

[Fran Blanche] used to make her own boards for her Frantone effects pedals, but as she admits it was a process that could at times be tedious. With increased production she had to move to using a board house, and for her that means a very high-quality local operation rather than one on the other side of the world. In the video below the break she takes us through each step of the PCB production process as it’s done by the professionals with a human input rather than by robots or ferric-stained dilettantes.

Though it’s twenty minutes or so long it’s an extremely interesting watch, as while we’re all used to casually specifying the parameters of the different layers and holes in our CAD packages we may not have seen how they translate to the real-world processes that deliver our finished boards. Some operations are very different from those you’d do at home, for example the holes are drilled as a first step rather than at the end because as you might imagine the through-plating process needs a hole to plate. The etching is a negative process rather than a positive one, because it serves to expose the tracks for the plating process before etching, and the plating becomes the etch resist.

If you’re used to packages from far afield containing your prototype PCBs landing on your doorstep as if by magic, take a look. It’s as well to know a little more detail about how they were made.

Continue reading “How Commercial Printed Circuit Boards Are Made” →

Will Your CAD Software Company Own Your Files, Too?

February 6, 2017 by Jenny List 91 Comments

We’re used to the relationship between the commercial software companies from whom we’ve bought whichever of the programs we use on our computers, and ourselves as end users. We pay them money, and they give us a licence to use the software. We then go away and do our work on it, create our Microsoft Word documents or whatever, and those are our work, to do whatever we want with.

There are plenty of arguments against this arrangement from the world of free software, indeed many of us choose to heed them and run open source alternatives to the paid-for packages or operating systems. But for the majority of individuals and organisations the commercial model is how they consume software. Pay for the product, use it for whatever you want.

What might happen were that commercial model to change? For instance, if the output of your commercial software retained some ownership on the part of the developer, so for example maybe a word processor company could legally prevent you opening a document in anything but their word processor or viewer. It sounds rather unreasonable, and maybe even far-fetched, but there is an interesting case in California’s Ninth Circuit court that could make that a possibility. Continue reading “Will Your CAD Software Company Own Your Files, Too?” →

Gliding To Underwater Filming Success

February 5, 2017 by Jenny List 17 Comments

If you are a fan of nature documentaries you will no doubt have been wowed by their spectacular underwater sequences. So when you buy a GoPro or similar camera and put it in a waterproof case accessory, of course you take it with you when you go swimming. Amazing footage and international documentary stardom awaits!

Of course, your results are disappointing. The professionals have years of experience and acquired skill plus the best equipment money can buy, and you just have your hand, and a GoPro. The picture is all over the place, and if there is a subject it’s extremely difficult to follow.

[Steve Schmitt] has an answer to this problem, and it’s a refreshingly simple one. He’s built an underwater glider to which he attaches his camera and launches across the submerged vista he wishes to film. Attached to a long piece of line for retrieval, it is set to glide gently downwards at a rate set by the position of the camera on its boom.

Construction is extremely simple. The wing is a delta-shaped piece of corrugated plastic roofing sheet, while the fuselage is a piece of plastic pipe. A T-connector has the camera mount on it, and this can slide along the fuselage for pre-launch adjustments. It’s that simple, but of course sometimes the best builds are the simple ones. He’s put up a video which you can see below the break, showing remarkable footage of a test flight through a cold-water spring.

Continue reading “Gliding To Underwater Filming Success” →

Popular Printers Pwned In Prodigious Page Prank

February 4, 2017 by Jenny List 40 Comments

A new day dawns, and we have another story involving insecure networked devices. This time it is printers of all makes and descriptions that are causing the panic, as people are finding mystery printouts bearing messages such as this:

“Stackoverflowin has returned to his glory, your printer is part of a botnet, the god has returned“

Well that’s it then, you can’t argue with a deity, especially one who has apparently created a botnet from the world’s printing devices. Printer owners the world over are naturally worried about their unexpected arrival, and have appeared on support forums and the like to express their concern.

We are of course used to taking everything our printers tell us at face value. Low on ink? I hear you, my inanimate reprographic friend! But when our printer tells us it’s part of a botnet perhaps it’s time to have a little think. It is entirely possible that someone could assemble a botnet of compromised printers, but in this case we smell a rat. Only in farcical crime dramas do crooks announce their crimes in such a theatrical fashion, you might say it’s the point of a botnet not to be detected by its host. Reading some of the reports it seems that many of the affected systems have port 9100 open to the world, that’s the standard TCP printer port, so it seems much more likely that someone has written a little script that looks for IP addresses with port 9100 open, and trolls them with this message.

The real message here is one with which we expect Hackaday readers will be very familiar, and which we’ve covered before. Many network connected appliances have scant regard for security, and are a relative push-over for an attacker. The solution is relatively straightforward to those of a technical inclination, be aware of which services the devices is exposing, lock down services such as uPNP and close any open ports on your router. Unfortunately these steps are probably beyond many home users, whose routers remain with their default manufacturer’s settings for their entire lives. It’s a shame our printer troll didn’t add a link to basic router security tips.

If you want to have a little fun, some of the printed pages include an email address for ‘the god’. It would be fun to figure out who this is, right?

Books You Should Read: Making A Transistor Radio

February 3, 2017 by Jenny List 33 Comments

When a Hackaday article proclaims that its subject is a book you should read, you might imagine that we would be talking of a seminal text known only by its authors’ names. Horowitz and Hill, perhaps, or maybe Kernigan and Ritchie. The kind of book from which you learn your craft, and to which you continuously return to as a work of reference. Those books that you don’t sell on at the end of your university career.

Ladybird books covered a huge range of topics.

So you might find it a little unexpected then that our subject here is a children’s book. Making A Transistor Radio, by [George Dobbs, G3RJV] is one of the huge series of books published in the UK under the Ladybird imprint that were a staple of British childhoods for a large part of the twentieth century. These slim volumes in a distinctive 7″ by 4.5″ (180 x 115 mm) hard cover format were published on a huge range of subjects, and contained well written and informative text paired with illustrations that often came from the foremost artists of the day. This one was published at the start of the 1970s when Ladybird books were in their heyday, and has the simple objective of taking the reader through the construction of a simple three transistor radio. It’s a book you must read not because it is a seminal work in the vein of Horrowitz and Hill, but because it is the book that will have provided the first introduction to electronics for many people whose path took them from this humble start into taking the subject up as a career. Including me as it happens, I received my copy in about 1979, and never looked back. Continue reading “Books You Should Read: Making A Transistor Radio” →

The Gray-1, A Computer Composed Entirely Of ROM And RAM

February 2, 2017 by Jenny List 53 Comments

When we learn about the internals of a microprocessor, we are shown a diagram that resembles the 8-bit devices of the 1970s. There will be an ALU, a program counter, a set of registers, and address and data line decoders. Most of us never go significantly further into the nuances of more modern processors because there is no need. All a processor needs to be is a black box, unless it has particularly sparked your interest or you are working in bare-metal assembly language.

We imagine our simple microprocessor as built from logic gates, and indeed there have been many projects on these pages that create working processors from piles of 74 series chips. But just occasionally a project comes along that reminds us there is more than one way to build a computer, and our subject today is just such a moment. [Olivier Bailleux] has created his “Gray-1”, a processor whose only active components are memory chips, both ROM and RAM.

The clever part comes with the descriptions of how the ROMs are used to recreate the different functions of the processor, through careful programming. Some functions such as registers for example use loops, in which some of the address lines are driven from the data lines to maintain the ROM at a set location. The name of the computer comes from its program counter, which counts in Gray code.

The full processor implements a RISC architecture, and there is a simulator to allow code development without a physical unit. The write-up is both comprehensive and accessible, and makes a fascinating read.

It’s safe to say this is the only processor we’ve seen with this novel approach to architecture. Some more conventional previous features though have been an effort to create a processor entirely from NAND gates, and another made from 74 logic.