ScottsBots.Com - Blog

It looks like I will be retiring Feynman-Jr, it turns out that having two robots that do the same thing are not that good. Also there are a few design flaws in Feynman Jr. First, the motors are too fast, this will have to go on another outdoor robot (name t.b.d). Second, there is no good place to put an arm.

I am going to be moving parts to Feynman6 and then mounting an arm on it and will add a computer power supply so I can leave the robot plugged in 24/7.

The software of course will take a hit pending work on the new robot, the main driver for the software is "What will it do?" and I my goal, to get a beer, is completely dependent on on the arm and having the robot powered on most of the time, without having to worry about recharging the battery.

I learned that Feynman Jr. has a longer battery life than I thought. In short, it never ran low and was able to stay running during the entire presentation with a full charge, this is moving the robot around via remote and having the PC on entire time.

I had a few bugs with the C# Serial-HTTP bridge. As it turned out, this program bombed about 3 times during the demo and caused Feynman Jr. to run wildly and not stop.

Also the motors for Feynman Jr. are a little too powerful for the kind of fine motor maneuvers needed for orientation (i.e. pointing north) as it turns out the motors on Feynman6 work much better for such movements.

Carnot worked just find though I am not sure of my vision algorithms, I think they work OK, but have too much error to be reliable and consistent.

I have been working on a smaller version of a robot than Feynman 6, called Feynman Jr. I have also begun to refactor my Java API so that it will work with my new robots.

The summary of my new robot "Feynman Jr" is that he will have his own CPU (another EPIA Mini-IPX that I have used so successfully in past robots. But he will be shorter and smaller than the other robots, small enough to fit comfortably in my truck and light enough so that I can lift.

I have also begin a new API so that I can better have a re-usable architecture then have robot specific classes extend the basic architecture. But this API is not 100% Java, I have had to extend it using C#.

Why C#? Well the main reason is that I use WindowsXP Pro for the robot's operating system. I had tried to use Video 4 Linux a year or so back and got nowhere fast. So even though Windows XP cost some money, it's rather stable for what I want to do, transport Serial and USB Web Camera data over HTTP.

By using HTTP for transport, this opens up any language to be used for processing. So PHP, Ruby, JavaScript, and other languages can be used to access the robot's control and data streams... Which is very, very cool...

I have started a blog at ScottsBots.Com. Well, it use to be my "Bot Bits" column but since I rarely used that and wanted to start talking more about robots, I decided to shift that to a blog. I will talk here about some of the latest news with my robots and programming. Stay tuned over the next few days I will be adding some more content ...

I was able to do this with 2 resistors and 1 capacitor.

      681 kohm        470 ohm 
Vx ----/\/\/\---o-----/\/\/\----Pin to stamp
unknown         |
voltage       ===== 0.01 uF film
                |
               Vss

The source code for the basic stamp is:

' {$STAMP BS2}
' {$PBASIC 2.5}
' {$PORT COM1}

rct VAR Word    ' RCtime value
Vx VAR Word     ' voltage value calculated
Cn1 CON 48576   ' first constant, see below
Cn2 CON 8       ' second constant, ditto
' circuit attached to P15
LOW 15
start:
RCTIME 15,0,rct
LOW 15
Vx= Cn1 / rct + Cn2
DEBUG DEC ? rct,DEC ? vx
PAUSE 500
GOTO start

You will have to experiment with the constants and values. I had to sit with my battery and take readings while I worked on the robot, then as the battery drained I took readings and voltage measurements and made my self a look-up table.

COJUG - The Central Ohio Java Users Group has meetings the 2nd Tuesday of the month at OCLC.

The demo's went OK. I had problems with the transport of the robot, since it weighs about 200+lb and with WindowsXP Home, which the robot was running. I think the PC was too slow for all the graphics that needed to be done, it also ran out of battery power about 90 minutes into the second demo. About 60 minutes in WindowsXP home started consuming 100% CPU utilization, not sure why this happened...

Other than those things, everyone really seemed to enjoy watching the robot and learning other things about Java.

Go to my new online store.

I have started the new club called the Columbus Robotics Society. I even had a nice article written by the Dispatch.

I have added the JavaRobots project at SourceForge.

This is my new robot site, moved from www.scottpreston.com. I have not moved everything yet, but I will get there by this week-end.

Now that the book is done I am finally going to start reviewing products and creating guides.

If you would like me to review your products or write about something contact me.