Reverse engineering? The new Wiring S board

In the fall of 2008 I started researching Arduino for an introductory article for Elektor. In that article I wrote that Arduino can be seen as a simplification of Wiring. The Arduino environment is very much like Wiring but slightly simplified and the Arduino Diecimila, the board of choice in 2008, was much simpler than the Wiring microcontroller board that had more I/O ports available. It is difficult to prove that the huge success of Arduino is due to this simplification, but the fact is that the current estimate is that more than 300,000 Arduino boards have been sold world-wide, which is pretty impressive.

The people behind Wiring must have been a bit jealous of this success achieved by others with their work so they started simplifying too. The result is the brand new Wiring S board that is almost the same size as an Arduino Uno. The Wiring S team apparently decided that they wanted to do things slightly different than the Arduino team, so the board looks a lot like an Arduino, but it is not compatible. Where Arduino uses mostly ATmegaXX8 controllers, the Wiring S board is based on an ATmegaXX4 controller (ATmega644 on my 1.0 board). The connectors look very similar, and are positioned in a similar way, but there are 5 instead of 4 and the pin-out is different. Also the project is open hardware, but the design files are in KiCAD instead of Eagle.

Seeeduino (left) and Wiring S (right)

It is rather interesting to see how Arduino is becoming more and more complex with programmable USB interface chips, all kinds of different processors and more connectors whereas the Wiring S board is almost like an old Arduino Diecimila but with a bigger processor. The board even offers the possibility to replace the FTDI USB/serial converter chip by an FTDI cable which brings it very close to the even older Arduino Serial. The two teams seem to be working in opposite directions.

For the people who would like to have the best of both worlds, they should use Wiring because the Wiring environment is capable of handling Arduino boards, whereas the Arduino environment does not handle Wiring boards and a Wring Play Shield is available that allows you to stick Arduino shields on the Wiring S board.

The Wiring S board is simply rectangular with its extension connectors on a 0,1” grid and 4 mounting holes placed in a logical manner. I do not like the position or the shape of the reset button; it is too hard & difficult to press. The solder side of my board was not cleansed properly and this seemed to be true for the whole batch received by my distributor. Maybe this is a pre-series problem?

Retro yellow LEDs!

Will the Wiring S meet with the same success as Arduino? Hard to say, I guess not, it is probably too late now.

RS Components presents new website

If you design your own electronics circuits you have to select the best parts for your design. This can be very time consuming especially if you do not know where to look for them. For me problem parts are electromechanical parts, connectors, push-buttons, that sort of thing. What I do in those cases is look through a component distributor catalog and see if I can find something to my likes. Unfortunately these catalogs no longer reflect very well the full offering of the distributor’s products as they prefer to present them on-line.

On-line component browsing on a distributor site just is not very practical. When Digikey decided to stop distributing their paper catalog we did a little reader’s survey of which the outcome was unanimous: No!!!
If you do a search on a part you will get many useless results, but you will also miss many because the search engine didn’t find them. Typical is the table refinement option where you can tick the specifications you want. You cannot simply tick one because often the same specification is listed several times with different wording so you have to tick ‘em all. Also ticking an option will remove the parts for which this particular parameter was not specified in the first place. “Number of ways” or “polarity” can mean the same thing for a switch, but the filter only knows one of them. Voltage regulators are one example of hard to select parts. Input voltage range, output voltage range, type, etc. all parameters that can be (and are) specified in different ways making them difficult to compare.

RS Components just launched their new improved website where they put a lot of effort in improving the search engine. They told me that they now remove much more irrelevant results and they return harder to find results, but they didn’t say anything about addressing the issue of parameter homogeneity.

So is it any better now? Let’s try to pick a low-dropout voltage regulator. The RS website returns 58 results (September 30, 2011, 14:00 h CET). Filtering on “Input Voltage” only shows 19 possibilities; strange, what happened to the other 39 parts? They have no specified input voltage? I find that hard to believe for a voltage regulator.

There are three parts with an input voltage range from -1 to 40V that turn out to be three versions of the same device (UC3836/2836 from TI). There is only one device with a range of 3.5 to 36V (LTC1624 from Linear Technology) but it is not the same as the TI one although the input voltage range is inside the -1 to 40V range, so the TI part would be an option too.

The filter proposes four devices with an input voltage of 40V without a minimum value. The result is again four similar devices, again from TI, but this time the UC3834/2834. Looking up the device on the TI website I discover that TI specifies an input voltage range of 5 to 35V for this device, not 40V. So what do they specify for the UC3836 on its product page? 6 to 40V! Eh? But RS said -1 to 40V, right? Yes, but actually that is the absolute maximum range. Duh! In that case, why didn’t they use -0.3 to 36V for the LTC1624? Pears and apples, that’s what this is.

Now you may think that I spend a day or so on finding this example, but no, I didn’t. I found it while typing up this post. It was that easy, meaning that it is the same for other parts. It is still very hard to use a distributor’s website for selecting parts for a design. The new RS site does look slicker and maybe the search engine is better, but I am not sure if I will notice the difference.

BTW, did I mention that the filter button doesn’t work in Firefox? I suppose (for now) that’s just my Firefox being incorrectly set up.

Open World Forum 2011

Saturday 24 September I joined two of my colleagues at the Experiment Day of the Open World Forum in Paris. Since it took place not far from the Crazy Horse I had no difficulties in finding the venue. My colleagues had come the day before by car because they had to bring books and magazines and especially the OSPV1, our open-source auto-balancing two-wheeled vehicle that we were to present.

The OSPV1 self balancing vehicle

The Forum was held in a rather high-class venue that had been paid for by a very impressive collection of sponsors in one of those rich “quartiers” of Paris where you get more easily run over by a Ferrari then by a Peugeot. The Open World Forum is all about Open Source; here the first question people ask you about a product is what license it is released under. I tend to associate Open Source with financially impaired people (i.e. students) with beards and spectacles hacking away in poorly furnished rooms and so it seems strange to actually meet these people (who came indeed pretty close to how I always had imagined them) in such a high-end place. Free lunch & drinks for everybody, all you can eat sushi in the pressroom, a real “we don’t care about money we only care about Open Source” attitude.

The ambiance was quite arty and inspiring with many great projects being showed off. It was interesting to meet so many people working with electronics without having a formal electronics education. They simply define an objective and then see what they can do with plug ‘n’ play electronics like Arduino to achieve it. These are electronics users (or should I say consumers) that embed ready-made building blocks in their projects.

I was a bit disappointed by the number of visitors. For some reason too few interested people made it on this sunny day to avenue George V. Maybe they didn’t have the money for a metro ticket? Make sure you visit next time, it is definitely worth skipping a lunch to save some money to pay for the trip.

Everything you always wanted to know about klystrons and traveling wave tubes (but were afraid to ask)

Most of the time this blog is about embedded electronics, but if I come across something interesting that is electronic but not directly related I will talk about it here too. Therefore, this time I will write about a book with the impressive title: Klystrons, Traveling Wave Tubes, Magnetrons, Crossed-Field Amplifiers, and Gyrotrons It is written by A.S. Gilmour, Jr. of the State University of New York, Buffalo and the book is edited by Artech House. The editor presents it as: The culmination of the author’s 50 years of industry experience, this authoritative resource offers engineers a thorough understanding of the operations and major classes of microwave tubes.

This field of electronics definitely has the coolest named devices of the industry and I sure would like to use a gyro-twystron once in my life, just so that I can say I did. Controlled by an Arduino maybe? Anyway, I’ve read this book and found it, to my surprise, quite fascinating. 800 pages about electron guns, exotic materials to make cathodes with, magnetic and electric fields and incredible amounts of power, actually this book is more about physics than about electronics. What I really liked about it was the mix of well established theory and experimental physics. The author does a pretty good job, as far as I can judge, at relating the complete history of magnetrons and the like. From the initial idea to the many tweaks that took the devices to where they are now, everything is described and it all feels very hands-on and experimental.

For the people that have to really study this material the book contains a wealth of drawings, diagrams, formulas and equations with derivations. I don’t think you will be able to actually construct a working megawatt gyrotron just by reading this book, it lacks the electronics, but it definitely will get you started. If you don’t care for the math, you can skip it all. Since the book introduces many terms the reader may be unfamiliar with it includes a glossary at the end. Your knowledge of vacuum pumps is a bit rusty? Read appendix B on vacuum technology. Appendix C gets you up to speed with magnetics.

I have only one negative comment about this book: the illustration the text is talking about is almost always on the back side of the page you are reading. Since there are many drawings you keep flipping back and forth between the drawing and its description.

This book does not introduce new theory but it is bound to become a standard reference for the serious high-power RF/radar engineer who has always a klystron lying around on his desk.

Wireless audio over 2.4 GHz

Just before the summer my contact at Texas Instruments had the excellent idea to sent me a CC85XXDK-HEADSET development kit. This is a PurePath Wireless Headset Development Kit to evaluate the new wireless audio products from TI based on the CC85xx family of RF micro-controllers. Due to a lack of time I didn't have the opportunity to write about it earlier, but I did give it a try and was impressed.

The kit contains two identical cards, one of which is configured as a master, the other as a slave. Both contain a 2.4 GHz radio and once paired (a simple operation) you can stream high quality stereo audio from the master to the slave. This works exceptionally well according to my non audiophile ears. The cards are each powered from one 1.72 Wh rechargeable li-ion battery, so it is a totally portable system. Charging the batteries is done by hooking the boards up to a USB port. TI claims a continues operation of 22 hours for this system.

I gave it a try in my garden and managed a Line of sight (LOS) distance of some 45+ meters (then I ran out of garden). It will probably go a bit further when the master is higher up from the ground. Occasionally the receiver has drop-outs, then it suddenly goes from full quality audio to complete silence, but this happens only at greater distances or when the data path becomes obstructed. Never did I hear any garbage out of the headphones.

Included in the kit is a little CC Debugger pod (with a funny rubbery feel) that you can use to reprogram the boards. This pod lets you reprogram and configure the boards using a tool called PurePath Wireless Configurator. The purpose of this tool is a bit unclear to me as there doesn't seem to be a whole lot that you can configure, but it is probably useful when you develop your own systems.

If you need a high quality wireless audio link in your system, the CC85xx is definitely worth a look!

Chasing tornadoes

This is my last post live from NIWeek 2011, my plane leaves in a few hours and the show is finished now anyway. Looking back I had a good show with many interesting and exciting! encounters, technical as well as human. Look, I even made a friend.

He is great because he plays soccer and he is as good at it as I am. I bet he dances like me too.

Today was the last keynote during which several impressive student projects were presented including the world-wide winning (www) project in the student project competition. This was a 3D display that you can actually build at home thanks to its extraordinary simplicity.

The keynote ended with a presentation by Tim Samaras who chases tornadoes for a living. Tim showed some very spectacular footage of tornadoes but also of lightning, because that is his second hobby. He and his team film lightning with very high-speed cameras so that you can actually see how the lightning makes its way down to earth. Wow.

With a bit of luck I will be back here in Austin, Texas next year. If so, maybe see you then or there!

LabVIEW, Arduino & Android

During lunch today I picked up the words LabVIEW and Arduino. Now that got me interested (or excited, as they would say here) and it turned out that a technical session about hacking Arduino with LabVIEW would take place later in the afternoon. So I attended and learned some very interesting things indeed.

First of all that it was not only about Arduino. To be totally honest, Arduino was a bit of a minor topic, the more important topics concerned interfacing to the Kinect, the Wiimote, iRobot, Neato and Android systems. Nevertheless they did do Arduino too. NI uses interns to develop all sorts of fun applications with their products. Waterloo Labs - who earned their fifteen minutes of fame about a year ago when they drove a car using an iPhone and posted a video about it on YouTube - is in it too.

So how do you interface Arduino to LabVIEW? It is pretty simple. You load Arduino with a special sketch to create an I/O server. Then in LabVIEW you install some VIs for Arduino. You should also install the NI-VISA serial port drivers if you don't have them allready. That's about it. And the great thing about this is that it is all free and open source!

Let's be clear about this, you cannot create a program in LabVIEW and then run it on the Arduino. In this setup Arduino is merely an input/output device, but a very cheap and hackable one for which many shields are available and you can use all the power of LabVIEW to control it or process the data. And if you replace the serial cable by a wireless link (Bluetooth f.i.), it is almost if Arduino is running stand alone.

This is all excellent news, because now you too can interface your project to LabVIEW as long as it has a serial port. All you have to do is port the sketch to your hardware and adapt the VI.

All this stuff and much more, like how to hack the Kinect or the Wiimote, is on LabVIEW hacker dot com