Older blog entries for cgates (starting at number 2)

Jim, Your not the only one that spends time thinking about or physically exploring robotic motions. A friend of mine here at work and I spend quite a bit of time drawing on the white board tring to figure out some robotic related issue or other. And yes some of the other people in our department don't get it.

All, I've made some more updates to my website. The "6808_bench" project site is finished for the most part. The only thing more I want to do is add soft copies of the datasheets for the major componets. I realize that the 6808 was first produced in the earily 80's, and that 2732 EPROMS and 2114 RAM chips have been around atleast that long. But, I can't seem to find soft copies of these datasheets anywhere. I have hardcopies that were printed almost a decade ago, but why don't the manufactures keep soft copies in some sort of online archive? I've just about exhausted all of my leads on the internet, I think I'm just going to have to scan the hardcopies and post the JPEGs. If anyone has any ideas where I can find these datasheets let me know. cgates@adt.com

I have been making some progress on my robot. I found my problem with the CPU circuit I bread boarded up, forgot to init the stack-pointer in the test program I put together. The hardware seems to be working just fine, I've started working in ernest on the software. I'm hoping to have the first version of the software done in a week or so.

I have spent the last couple weeks working on breadboarding the CPU for the motor deck , still working a few problems. I also started work on my robotics web page, Its not complete but if anybody is looking for a 6808 cross compiler and manual, I put one on the website. I'm hoping to get some pictures for the projects posted soon. I really need to get a digital camera, would simplify this process significantly.

I started sections for three projects on my web site, "6808 Bench unit", "DMC Display" and "Turtle." The "6808 Bench unit" is what I use to build and test peripheral projects that will connect to a 6808 based project. The OS in the Bench Unit makes trouble shooting the circuit and driver software fairly easy. The "DMC Display" project is a generic interface circuit to connect a Dot Matrix Character LCD Display to a micro processor. I've used these displays on serveral projects. "Turtle" is the name I've given to the motor deck portion of the robot I'm working on. I chose the name turtle because the interface language will be base on the "turtle logo" concept. The control deck will issue "logo" type commands to the motor deck. My web site will have enough detail about each project that anyone wishing to duplicate on of these projects should be able to find enough detail to do so.

I found a company up in Boulder Co. that sells sonar units. They have a full kit that will do 6" to 35 feet for about $40. I'm thinking about picking up one of these. http://www.acroname.com The part number is R14-sonar1.

Finished construction on the Dual H-bridge board that will controll the two motors on the motor deck. A second board on the motor deck will send the PWM (pulse, width, modulation) signals to the H-bridges to control speed and direction. This second board is designed around a motorola 6808 mirco. This board is not going to be the brain of the robot; instead it will receive commands from the controll deck. This approach will has the affect of offloading the service routines for the PWM, wheel encoders and the line follower. The data from the encoders and the line follower can be made avilable to the controll deck through the command interface.

The hardware design for the controll deck is finished. I'll start working on bread-boarding the second board for the motor deck soon. I have several of the PWM service routines already writen and tested on my bench unit, this was done while I was finiallizing the design of the H-bridge.

My home webpage hasn't been updated since I started this project. I've taken some pictures and will post them along with images of the schematics and copies of the source code. Anyone interested in learning more about this project is encouraged to visit my website.

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