Getting serial on my Mac has been something I’ve wanted to get going for awhile, but like my blog and my time….

How to get a serial port up and running on my OSX laptop?

Most USB serial devices are exactly the same or at least they are built up from FTDI or compatible chips that you can find here at In fact, that’s a great site to buy exactly what you need, though I bought my locally. Therefore drivers for pretty much any of the sources are the same or similar. I have seen bad performing devices, so perhaps there are some low-level firmware tricks, but mostly one doesn’t need to know about those hardware/firmware implementation details and just find a good and fast device.

I have a device that is manufactured by Tripplite that looks and is typical to ones from other manufacturers.

“PL2303 USB to Serial Driver for Mac OS X. It supports different manufacturers of PL2303 based USB to serial dongles like ATEN, IOData, Elcom, Itegno, Ma620, Ratoc, Tripp, Radioshack, Dcu10, SiteCom, Alcatel, Samsung, Siemens, Syntech, Nokia, MS3303H”

So was it hard to get running on OSX? No. Knowing some tricks is helpful, or really only one trick. Connect pins 2 and 3 of the serial port device which connects the RX and TX pins (aka receive/data-in and transmit/data-out serial) to test it out. Here are the steps:

  1. Download the device installer of an OSX open source driver from ( Run it.
  2. You can ignore the network configuration depending on your intended use or at least to test your device/install.
  3. Find the device name by opening up a Terminal window and typing ‘ls /dev/tty.’ to see all of the serial ports available. Hopefully, there are many and it’s obvious which is likely.
  4. Once you have the name and pins 2 & 3 connected you can open up port with ‘screen your-device-name-here 9600’. The 9600 is for 9600 baud.
  5. Start typing in that window and you should see the characters type echo on the screen, disconnect the pins 2 & 3 and the characters will stop, since the TX pin is no longer sending them back into the RX pin.
  6. If that works, you’re up and running. If not, make sure you didn’t make any mistakes and try again. Try another USB port (your device name will likely change). One can also try the device on a Windows machine with Hyperterminal, just to make sure it works.



27 October 2009

I’m going to read this in more detail, but on first brush, I find it interesting.

Oh The Tools I Use…

29 March 2009

This is my first posting from an on-going series where I’ll describe the software tools I use.

The first tool I want to describe is my RSS reader. Like a lot of my tools, I read about them for awhile before I understood the benefit fully. This tool, of all my tools is the one takes a lot of time of my time, sometimes to much time. It also changed the way I use the Internet more than any other tool including search!

I tried several downloaded podcast/RSS reader applications, but those never worked well for me and my mind. I don’t remember the names, so please don’t ask. I also work at multiple locations, and often with different computers, so off-line tools don’t work well for me in general.

I do love working in the cloud, where Google pretty much owns me (more on that soon). I’ve been an online email only guy for 8 years starting with Yahoo Mail, which has an amazing GUI for online, but GMail’s thread discussion own me now.  More on those later…

Initially for RSS, I used Yahoo or specifically My Yahoo. For a while, hooking up those to RSS feeds worked OK for me. I’m not sure when Google Reader (GR) came out and not to long after I tried it, I was hooked.

Like many, GR changed the way I use the web completly. I don’t web surf anymore and I pretty much only read my feeds, search/lookup something, email, some minor social networking and not much more. I don’t just click around and surf ever anymore, because so much interesting stuff comes through my feeds than I have time to read about, listen to or watch (isn’t video on the web incredible?). Most of the sites I subscribe too, I found from another site I’m already subscribed to. Over time I manage these sites and weed out the ones that are mostly echo chambers.

One thing GR gives me is a way to communicate with friends and colleagues when I find something that I know would interest them, I forward it to them. Another one of my favorite parts, but hasn’t seem to caught on with any my friends is the social part of GR where you share or publish interesting things you find. Here is my list (call me 16867871631588463335….um how about my gmail address?), which nobody likely cares much about except me. That’s what makes it interesting because it describes the perhaps hidden me into the ‘social me.’

On the social thing-a-ma-goo. Twitters sounds interesting, but also sounds like a BIG time sink given my experience with GR. Facebook and MySpace, while my kids and some friends are into them, they don’t interest me. I don’t totally get ot social network fad yet, but I have a few business ideas about that are brewing in my head, mostly about Jabber uses.

One of the concepts, though not my idea, integrating social networking concepts is the startup I’m at CarefulProducts aims to bring social connectivity and medical compliance to senior care via in-home monitoring. I have severeal other ideas, but those are baking or waiting for someone else to do them ;>(.

The only social tools I really use are (nice RESTful link BTW:, but I think I had to reserve it) and my blog. Others might not consider it a social tool, but my feelings about what should be but it is, though not trying to be (just call me 3226 please….um what’s wrong with the just the kenny/username already in there?).

More about this stuff later, since this is about GR. I love Google Reader and you should too!


I’ve been working with WCF in my new position at I really like WCF and the new job. I’m reading this book about creating and using WCF RESTful implementations with .NET 3.5 SP1. I’m also new to Windows 7, skipped the Vista fun. For a while, I’ve been struggling on Windows 7 and especially its security. Why do they move everything with every release.??? Argh!!

I never really understood the uses of an application manifest file exactly, but this article really helped me get it at least for what I’m working on. Now I don’t have to keep punching holes into the firewall for my WCF hosting applications and figure out where they moved stuff in Windows 7…b**tards!

While I’m at it, I’ll put a plug in 😉 for this code project article. Anything to avoid learning IIS….again! Sorry, but I think I have Mono.

This weekend, I’m coding up what I call a RESTful Content Exchange Service (CES). What this service does, is provide access to and the ability to create remote ZIP files of content. Content being media files, software updates, etc… all balled up in zip files.


My 2nd Law of Vision is called Kenny’s Rule of Fist. It’s a pun on a rule of thumb, as each of my Laws of Vision really are. The idea behind the Rule of Fist is that vision systems can get difficult or complicated when the object being analyzed is larger than your fist. Again, as with the 3rd law, it means you may have to make special choices, play tricks, purchase expensive hardware, etc…

Why a fist?

Well you don’t want to cut off your thumb!

It’s because your fist is pretty big and the resolution in the standard camera is not that great, so as objects get bigger you can not evaluate things that are significant relative to human vision. When you want to look at things larger than your fist you will be looking at courser details or measurements.. People, or worse customers, ask “Why can’t it see that, it’s obviously wrong!”.

Objects being big also bring into play and can create parallax problems of z-order measurements as you have to move the camera toward and away from objects. In addition, they can also create distortion problems of the lens if you try to use wide angle lenses. One tool to help solve z-order parallax is a telecentric lens which is a really cool thing, but you have to get a really big and really expensive lens if the object is as big or bigger than your fist.

Objects larger than your fist can be problematic for machine vision system design. So always consider my 2nd law or the Rule of Fist.


My 3rd Law of Vision isn’t related to my current task, so I thought I would logically discuss it first…. huh? Yeah, that’s how my mind works, sorry.

The 3rd law is called Kenny’s Eye Rule. The idea behind it is that vision system can get difficult or complicated when the object(s) being analyzed are moving faster than the eye can see. By being difficult, it means you may have to make special choices, play tricks, purchase expensive hardware, etc…

Many people don’t realize it but our eyes cannot see things that have a periodic frequency of not much greater than 50 Hertz (Hz) or objects that move back and forth 50 times per second. It’s true! The video we watch typically comes at us in discrete or digital frames. It’s true, even if it’s an analog TV. You can see this with any TV/computer, where you can can get temporal aliasing. You know, that effect when it looks like spokes on a wheel are spinning backwards. This is our natural humanity given built-in 50Hz threshold and it’s why TVs and monitors run at, or better than that frame rate.

The original analog TV system didn’t. Those systems actually run at a 30Hz frame rate (US), which would be really annoying if they didn’t pull out a trick on us. What those tricky engineers did was transmit half of the picture, the so-called even lines, and then the odd lines of the frame. These are often called the old and even fields, but what it gives us a 60Hz field rate, which spatially tricks our eyes to not notice, as much, the 30Hz frame rate that would be bothersome. Good trick, smart guys.

Why the history? Well the tools we tend to use in machine vision are based on standard video cameras and thus that 30Hz frame rate sepratated by two fields. There are special cameras, but as you might suspect, they are expen$ive and we try to avoid them, if we can. Hell, if a $50 camera does the job, use it! Sometimes they don’t, so…..

That’s where Kenny’s Eye Law comes in. We most often use those cameras and thus are bound by their limitations of frame and field rate.

I developed Rule of Eye, when I was helping a client develop a system that inspected the top and inside sides of bottle caps in Italy. Yes, the bottle caps that seal the top of beer bottles and the like. This was about 15 years ago and those machines were a mechanical wonder for me. The machine formed these bottle caps from flat metal and applied the inner seal at >50 caps per second. At that speed, the caps look like a continuous piece of metal. This system had two cameras: one inspecting the printer on the top and one inspecting the ‘crowns’ or desired number of folds in the metal and the quality of the inner seal.

So, that system worked faster than a standard video camera of 30 frames per second. How did we do it? We used the reverse trick of the original TV engineers, we just used 1/2 of the image and we used both the even and odd halves. That way way we could capture 60 images per second with a standard camera. Pretty cool, eh!

Another system, I worked on for a client more recently (ah um 8 years ago?), was a adaptive mirror control system. This company’s product was used in fancy pants telescopes. Its clients including thos looking up into space, often scientists, and those looking down from space to earth, often the military or spies. The goal of the adaptive optical systems was to adjust and remove as much of the optical distortion caused by our atmosphere and produce a clearer image. Wow! Don’t ask me about the physics of it or the optical system worked. But, I was able to help with the machine vision task they needed to do.

What we needed to do was track a number of dots where each represented a mirror position in XY or tilt or distortion in this case. The first and primary system I worked on had 37 mirrors or dots across the field of view, each moving slightly betwen the frames of the images. To do the system’s job, we had to track each of those dot positions and feed the XY cordinates into it’s closed loop control system. That control system would calculate and set an adjustment of the tilt for each of the mirrors with every new image and new XY positions of the dots. To effectively manage this control system, they needed to track these positions at almost 1000 image per second. A kiloframe per second! (think Doc in Back to the Future) Huh, we can’t do that can we? Yup, but we had to buy a very expensive camera that could capture images at the rate.

Needless to say, I hope! Having a system that moves faster than your eye can see complicates the development of a machine vision system. That’s called Kenny’s Eye Rule and my 3rd Law of Vision.


Kenny’s Laws of Vision

31 January 2009

Years ago, 2 and 1/2 and since 1990, I developed many machine/computer vision applications for a number of clients and at some companies. Most of that work was for clients through my consulting company Imachines. This last week, as I noted before, I’ve rejoined with my past and I’ll be developing machine vision solutions again with

During my career with vision, I developed what I affectionately called Kenny’s Laws of Vision. I have three that I remember:

  1. Kenny’s Law of Light
  2. Kenny’s Rule of Fist
  3. Kenny’s Eye Rule

I’ll describe my Laws of Vision (LOV, yes it’s sweet)  in more detail in future posts. Two have relevance to my current task and I’ll describe why I need to be careful at Careful Products. Sorry ;>)

Our goal at is a computer monitoring and social networking for seniors with a really easy to use gestured based touch screen system. It will provide tools for family and friends to keep in touch, communicate easily, schedule setting/monitoring and to monitor their meds compliance. Or as Amy at my Starbucks came up with when I described it, NanaNet.

We don’t want to have the computer decide about medication compliance, but we want to be able to communicate, (e.g. email, PicMsg, Facebook wall post, etc..) with concerned or interested parties images where they can determine whether or not the medication has been removed as well as their patterns of communication, etc…

More soon…


%d bloggers like this: