How did you get into electronics/ engineering and when did you start?

In 1980, my father bought one of the first home based computers, a Compucolor II system based on an Intel 8080 CPU. I was seven back then, so when my dad and his buddies opened up that big beast in an attempt to increase the abominable amount of 8KB of RAM memory, I could not help but to be mesmerized by its printed circuit board filled with what looked to me like a gazillion little “cockroaches”.

After that, I developed a voracious appetite for understanding how electronics worked. My brother’s toys were next in line, which allowed me to start a small collection of motors, wires, LEDs, batteries and other components. Fast forward about a decade later. It was time to choose a college career, and my obvious choice was electrical engineering. As of today, I have never come to regret this decision, and I do not foresee it ever happening.

What are your favorite hardware tools that you use?

When I sit down in my lab to code an application, at a minimum I use a Tektronix MSO 4034 mixed-signal scope, a Tektronix TCP0030 current probe, an MSP430 JTAG module, and my two hands. That latter is actually the most important piece of “hardware” I will ever have, so I make sure they are always protected (especially when working with power tools). With all of these powerful gadgets, I can make any of the electronic circuits I work with come alive and perform bug free.

I have all kinds of other nifty tools in my shop, such as a 25W CNC laser (Mercury Pro), which is a delight to work with because it is pretty much a 2D printer. If I need more intricate parts, either because they are too thick or because they are made out of metal, I use my Tormach PCNC1100 CNC mill. This is in essence a 3D printer, which I recently upgraded with the fourth axis.

All of these tools are making it a breeze to build my own CNC plasma cutter. Once complete, I really cannot think of too much that I would not be able to build – at least the stuff that I plan to build in the near future. Luckily a space ship is not in my list. Yet…

What are your favorite software tools that you use?

The great majority of my projects involve a PC computer talking to a board through a serial port, such as USB. To code the microcontroller firmware, I use either IAR or Code Composer Studio. To code the Windows Application, I love Visual Basic (Visual Studio 2010).

On the CNC side, I am infatuated with Auto Desk Inventor. At first it seemed like I would need a second brain to learn how to draw in 3D. After reading half of a book in the topic, I am drawing 3D models and assemblies, and I simply can not believe it. Needless to say, thanks to the CNC technology, whatever I draw on this software pretty much comes out as a result from the CNC equipment. For the laser, I use Corel Draw, as it has been optimized for the laser engraver industry and it is an excellent drawing package.

What is the hardest/trickiest bug you have ever fixed?

Any code concerning the real-time actuation of a motor is tricky by nature. There are code pieces in which you can stop the execution, look at a few variables and figure out where the problem is. With motors, however, if you stop the execution, chances are you will be stopping the motor as well. Sometimes you can get an idea of what may be going wrong, but if it is the real-time aspect of the design, it will require real-time debugging, which is quite intricate and requires an impressive amount of creativity.

From all the algorithms I have coded (microstepping, stall detection, dynamic current control, BLDC actuation, sensor-less commutation, acceleration profiles, etc.), the trickiest is anything with a PID loop. PID loops are a pain because if the system does not work, you’ll need to figure out if the problem is with the tuning parameters or the actual code. And of course, it is all in real-time, so stopping the execution just makes matters worse. Luckily, as long as you pack your patience, you should be able to gain visibility into what the engine is doing and how the system is reacting to external stimuli. You’ll identify the culprit eventually, but boy is it tedious work.

What is on your bookshelf?

I have way much more books than I will ever possibly read, a problem that was exasperated last Christmas when my brother gave me a Kindle, which I have been happily filling. My analog “bookshelf” includes countless magazines on electronics; books on microprocessors, microcontrollers and robotics; and all of my old college text books on topics such as physics, chemistry, psychology, electronics and math.

I have also been collecting books on how to build things, such as woodworking, welding and metal forming, machine shop studies, blacksmithing, mold making, etc. I also have books on coding Assembly, C, Java, Visual Basic, PHP, HTML, and other computer-related topics such as how to make animations, record music, video editing, etc.

The books that I tend to read the most, though, are those on laymen physics and philosophy, such as those written by Michio Kahku, Stephen Hawking, Brian Greene, Paul Davies, Richard Dawkins and Sam Harris.

Do you have any tricks up your sleeve?

I am a visual guy, so I try to see everything that I can. In electronics this is quite challenging, as we are dealing with controlling those pesky invisible sub-atomic particles. To make matters worse, they travel at the speed of light, and as I approach 40, it is hard to keep up with them. Luckily, there are plenty of tools to help me grasp the electronics’ world, visually. Sometimes, however, there is no tool! So I have to get creative and come up with one.

This is why I like the Visual Basic to serial communications to microcontroller toolset so much. Microcontrollers nowadays are like a virtual lab in a chip. The device that I use the most, the MSP430F2619 from Texas Instruments, has two DACs to output analog information, eight ADCs so that I can capture analog information, eight timers to either generate timing information or capture it, plus enough GPIOs to keep me entertained for a little while. And it runs at 16 MHz, which is more than enough speed for the stuff I deal with the most: motors. Everything else is code! The microcontroller can take the data in real-time and crunch it. If it is too much, I can then dump it into the computer where I have even more crunching power.

While the MSP430F2619 works well for me, I can think of many applications needing faster speeds. Luckily this technique is highly scalable. If a 16 MHz microcontroller is not fast enough, get an 80 MHz one. If 16 bits starts to look like an Atari 2600, get a 32-bit microcontroller. You can also try an FPGA or something as cool as the XMOS architecture. I am getting started with that one, and I have to say it is quite promising!

What has been your favorite project?

The project that has not only been the most fun but has in essence defined my life as a professional (and a geek), was building an R2D2 replica. I started in 1995 when there was no R2Builders club. I knew nothing of how to build an R2D2, or anything else for that matter. The growth experience was just exponential and the rewards outstanding. When you are able to build something by using your brain and then employing your hands, it surely beats buying it!

But R2 was much more than just a project. It was actually a colossal endeavor! I had to learn about composites, mold making, metal working, welding, machine shop, embedded system programming, motion control, robotics, etc. There is no place where you can go and say, “Hey, teach me all this stuff! I want to learn how to build a robot.” I had to teach myself. Curiously, although I set out to build a robot, I ended up building me, so to speak! I didn’t see that one coming…

Do you have any note-worthy engineering experiences?

Being chosen as a featured engineer on EEWeb is definitely an achievement, and I feel quite honored.

My career as an engineer has been very exciting, and I am thankful to be blessed with many successes. But the truth is nobody succeeds without failing at some point. As R2 was coming along, I was invited to one of the annual R2Builders “Build Off” events. Builders from all over the U.S. came together to work on their own units and to learn from what others had accomplished. I brought my replica hoping to show off my very first high-current design. Looking back, I should have tested the system at home prior to the event, but of course I didn’t. When I plugged the batteries in, the traces in which I had skimped in order to save on board costs vaporized in a cataclysmic melt down, taking with them some of the logic boards. The design was just too crude and poor, not to mention cheap, so I scrapped it and moved on to the one that I used to eventually drive R2, as well as other heavier robots. This was yet another experience in which I could not have possibly learned better on how “you get what you pay for”.

What are you currently working on?

My latest project involves the creation of a plasma-cutter CNC table. Although the CNC laser and the CNC mill are great tools, if I want to cut 2D contours in any metal, the laser simply can not do it, and the CNC mill does not necessarily do it well. The plasma cutter, however, can cut through most metals like butter. I could use my hands to drive the actual plasma cutter head, but I am addicted to CNC.

In parallel, I am designing the ultimate four-axis CNC stepper driver board. It will contain all the electronics, except the computer and sensors, you need to drive a small-to-medium sized CNC router or plasma cutter.

How did you get involved in the Dallas Personal Robotics group and about some projects you have worked on?

When I moved to Texas in 2005, I decided to switch from robotics to my parallel passion of music, as I did not have the space I had back in Rochester, NY. I miss those basements! The lack of space brought up a need to find suitable new owners for my robot parts and gadgets, and I was very pleased to learn there was a local club, the DPRG, dealing with precisely this hobby, art and science. They welcomed the donation and made me a group member, but I wanted to focus on developing my music skills, so I was not able to participate at that time.

Eventually I drifted back into robotics and officially joined the DPRG. Since then, I have helped them with their motor drive needs (all robots require this component if they are to move). They in turn provide invaluable input as to what they like to see in their control boards. This feedback has helped me improve a good portion of my board designs.

How did your blog/website come about?

While I was building my R2 replica, I was adamant about one rule: I had to build it all from scratch! If it applied to the mechanic aspect, it applied to the electronics as well. Hence, I started to design the electronics that would drive the robot. When more and more people started building R2 replicas, I thought of offering these boards as a product they could add to their repertoire. Eventually I figured, why limit the usage of these boards to just R2 builders? Anybody could use these on whatever project they could think of!

The Avayan Electronics website was born as a repository for my designs, enabling people to download files to build their own boards. The boards have always been modular enough so any project requiring a motor with the voltage and current capabilities of the board, can be easily tackled. Some people have used them to drive scale trains, others to drive solar panels.

As the acceptance for these boards grew, I was bombarded with questions. Instead of answering the same question over and over, it made sense to create a blog containing more detail on how to use the driver boards. I also have some YouTube videos detailing a few tricks on motor related topics.

Did you design the products listed on your website? Can you tell us about them?

Every design on my website originated from me. The designs you see on the website, however, are mostly the successes. And I am calling a success a board that works to anywhere in between 95% to 100% of its intended functionality, and the 5% of imperfection being mostly cosmetic in nature. For example, every now and then I space out, and the silk screen ends up having the wrong documentation. As much as I am displeased with these errors, the truth is that the electronic portion is flawless, which is what the board was meant to do in the first place. If it works, it works!

Sometimes I mess up pretty bad, though! If I get too hasty, usually out of excitement, I may forget vital components and even connections. These boards I do not post, as they would require too much rework to make them operate as intended. I hang on to them for other experiment, and if nothing else, they make for a darn good squeegee to apply solder paste. Luckily, the great majority of boards do come out good!

It is amazing how much I have learned in the last 10 years. The other day I found the very first board I designed and it almost seems like my requirements were to make every possible mistake I could think of. The component sizing is all wrong and the placing is worse. It takes a very small amount of time to read about the laws of physics, but about a decade to fully see how they impact the world around you.

My biggest improvements have been on thermal management. And even today I am always finding new techniques to improve my designs. You can see this throught my last three years of motor driver boards. First it was just lots of copper on the top layer. Then I added tons of copper on both layers. The next improvement consisted of adding a surface-mount heat sink on the top layer. Shortly after, I followed with adding mounting holes so I could add a heat sink from the bottom. Now I am adding another mounting hole to add a very powerful heat sink we just tested, which has lots of potential. What will it be next year? I don’t know but I bet there will be something.