Older blog entries for blueeyedpop (starting at number 6)

6 Volt Dual H-bridge

Well, I set forth to build a 6 Volt dual H-Bridge based on the TPIC0108B from texas instrumants. I managed to layout 2 of them on a 1.2" x 1.4" board. I received my boards today.

The low voltage is the key here. Many people ignore that when playing with the robotics stuff. The go for the LM18200 or LM18201, and fail to notice the minimum voltage. Wish me success.

ROBOGEEKS.com is coming along nicely.

I have been working diligently on content for it.

Look for articles on the following:

Mark III mini sumo review

Lynx Motion Hexapod III review

Addendum to my optical mouse hack

National Control Devices' Noritake VFD display.

Construction articles

Beginners Corner

I put a lot of time in this week on learning the IsoMAX, the state machine language of the IsoPOD. It's taking a bit of getting used to, but the reap is well worth the toil. Setting a virtual machine which scans an R/C servo back and forth at a variable rate was a really neat thing to see, considering it became a background task, and the processor was still available to me in the foreground ! I have been accused of ``pimping'' the IsoPOD, but simply put, in my opinion, it's the most powerful thing available to the amateur roboticist.

Tripe Odd? scuttled today! Cooked a servo, busted another, and broke loose 2 more. But!!!! It scuttled about. twirling and shaking, dipping and turning.


more to follow

I decided to build a 3 legged bot. Tentitively called "Tripe Odd?" 3 identical legs, 120 degrees apart. 2 servos for the swing/raise hip, 1 for the knee. The body is the case for an Apple AirPort. Built it in about 3 hours, too much glue, but it saves on time. If anything, it looks cool.

Will post again when it walks.

progressing on the IsoPOD. I built 6 state machines, each controlling an r/c servo. The servos follow a sine curve, and are enabled and disabled by i/o port lines. I wanted to see how fast could crank up the speed the state machines got processed, so I cranked it up to 500 times through the machine chain a second. I was able to manage over 27,000 floating point operations a second. This speed didn't crash the foreground.

Very impressive, 6 servos running independently, with no processor intervention required. Updating at 50hz, the natural rate of the pwm for servos, with 10 bit range, gave really nice smooth sine motion.

because they're multitasking in the background, I could change the values in their count and increment registers in the forground via hyperterminal.

Got the wind back in my sails again. I had been building my site bio-bot.com as a resource for the group of people I'm tutoring, but now I have been working on the "public" veneer.

keep looking


Present professional activity: As of now, I am employed at a place called Panavision, where I am developing robotic lens technology. I have developed high resolution encoding schemes for monitoring the focal length, focus distance and aperture of lenses. I have done some image processing work to map the distortion characteristics of lenses as well.

Personal interests also include holography, and I have developed some hardware to assist me in this area of interest as well.

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