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NEWT


This page is retired. I essentially decided that Newt wasn't sophisticated enough. See Skinny.html for the robot that took Newt's place. However, there are still some pretty kewl pictures and videos of Newt here.


Picture of Newt the Day He Was Born

Newt was a work in progress. You can track Newt's development by reading this page as a sort of diary in reverse (latest entries are first).

April 30, 1999 (last entry)


Newt with a few things added (see para. below). Newt's SONAR and IR detectors are on a servo which has about a 90 degree sweep.

Larger Picture of Newt (116K)

April 8, 1999

Wow... Lots of things going on... we're moving forward with the introductory class in microcontrollers so I'm collecting all sorts of gear for that. Meanwhile, I've made a three channel voltage detector for Newt, a bumper switch, an IR detector, and I've got the gear to set him up for a modular subsumption behavior approach. Which simply means that I've got a dual Stamp2 board that will handle the motors, SONAR, IR, and mechanical devices and I'll hook up the two Stamps to an onboard processor (either a laptop or an HC11) and let the larger CPU do the orchestration of it all. He needs an edge detector to keep him from falling down the staircase when his SONAR sees the empy space it reflects. Newt is now in about a thousand pieces and I'm rewiring him.


March 21, 1999

Well, I got the SONAR working and now Newt has rudimentary eyes. I'm still working on good software algorithms for him to find his way out of problems. The SONAR isn't as sensitive to things as it needs to be for standalone. Newt will need some IR and mechanical sensors to stay out of trouble. The following real media clip shows Newt get his way out of a corner and then promptly grind into the leg of a child's toy. He bullies his way through it all and finally makes it out to the center of the room (my basement).

Real Media Clip of Newt's new eyes. (222k)

www.real.com - pick up the latest Real Media Player for free.

Unless you've got a fast connection, it doesn't stream very well. Just down load the file and run it locally (much nicer).


March 19, 1999

Oops. I hate it when this happens. I was mounting a NEW Polaroid SONAR kit on to NEWT and I accidentally drilled through the circuit card. Interesting little pieces of transformer and stuff are now all over the floor. Oh, well... the SONAR worked for its test phase.... anybody got $50?

Here's the latest picture of NEWT (with a hollow SONAR head on his upper deck!). He sure looks different with yellow paint and an upper deck.

The SONAR head has a servo attached to it (that was what I was drilling when I screwed up the circuit card). I didn't want to buy two SONARs when I could make one do the job of many. Oh, well... I still get to buy two SONARs.

UPDATE!

Well, I got up this morning and decided to try to make the SONAR work anyway. I took the transformer that was drilled away from the Polaroid 6500 board and attached some 30 gauge wire to the leetle bitty wires coming out of the transformer. I then soldered them into the mangled circuit board and put a blob of hot glue on it to secure everything. I was missing a ground wire (it was ripped out of the innards of the transformer - but I think it was a ground for the core and not for the circuit itself) so I just left it off and fired the thing up. Lo and behold! It works! In fact, it works pretty darn well. (I still have a replacement board on order). If you are wondering, I did all this with a huge magnifying glass and Mr. Weller's famous workhorse. The fact that it works is just amazing. I felt so good, that I went down to Radio Shack and treated myself to a new multimeter (the true RMS digital one with hot and cold running water). Life is pretty darn interesting sometimes.

Things to remember when attaching a SONAR head to your robot:

a. Don't drill through the circuit card. It complicates things.

b. Be sure to add a pull-up resistor to the ECHO line. Some of the instructions omit this step and the SONAR will not work if you forget to do it. The Echo line is an open collector circuit and requires the pull-up. I used a 4.7K and tied it to 5 volts.

c. Don't stick your ear next to the SONAR. It hurts when you do.

Larger Picture of NEWT in his new dress


March 16, 1999

Newt now has an upper deck (and room for one more deck if necessary). He is currently disassembled and painted. When the paint dries, I'll put up another picture.

I've settled on Newt's first real processor. I've been jumping back and forth between just putting a laptop on him and having all the power I needed (but at the cost of complete overkill and terrible weight), or to mount a pretty good CPU on him and compromise on some of the kewl things a laptop could do on a robot. Since Newt can handle either scenario, I decided to put a smaller CPU on him first and see how it goes. I just ordered a Zorin ModCon controller (which is HC11 based). We'll put it on first and see what develops. Zorin is at www.zorinco.com


March 10, 1999:

Newt is a development platform.

I realized that lots of space, the ability to carry a pretty good load, and reasonable size were the parameters I wanted for a really good test bed. I also wanted it to be stackable (more than one tier for electronics, payload, playing).

I first tried a 12" square platform and that was immediately abandoned. It looked like crap and it kept getting snagged on things. I chose 12" because I wanted to be able to put a laptop on the 'bot if I so desired. That drove a few other things (like more powerful motors and a bigger power supply). I finally settled on a 12" circle for the base with a 1" hole in the center for wire stringing.

Brains:

Right now, Newt has a Stamp2 on a proto board that drives him around the house. He doesn't have any sensors. That will soon change a lot. The Stamp2 is just to get him going to test the basic design. A more powerful setup will probably be needed.

Power

I used 1/4 scale servos for power and I made a hacked holder for two Black and Decker VersaPak NiCads. This gives me 7.2 volts for the motors and a simple change out system (probably easy to build in a self charger, too). If more current is needed in the future, I can always string more nicads together. These NiCads are light and powerful (they drive my wife's portable vacuum cleaner - so they ought to drive Newt).

The 1/4 scale servos were a bit of a worry at first. I hated to invest in them and find they weren't going to do the job. But, I consulted with a few people and then plopped down the money. A nice feature of these particular ones is that they are bearing drives and when you hack them to make them 360 degree capable, the potentiometer inside actually drops out and can be used outside. Early on, I stuck my Compaq laptop on this thing and it merrily dragged it all around with it. Anyway... I've got all kinds of dreams for this puppy. We'll see how it goes.

In the end, by doing the job with mostly individual parts, this platform cost less than a 6" platform kit and, IMHO, it has a lot more kewl quotient. I jammed a 14 qt garbage pail on top of it and it looks pretty snazzy (see picture link below)

Newt's Butt. Shows the NiCad setup. (300K)

Bigger picture of Newt (300K)

Newt with a garbage can on his head (75K)