Older blog entries for cgates (starting at number 6)

7 Jan 2002 (updated 7 Jan 2002 at 21:27 UTC) »

Fixed the bug on the schematic page. There is now a chassis wiring diagram, a schematic for the H-bridge and a schematic for the motor deck's CPU board under the robot project.

SuperDave, I havn't worked with that exact chip before but programing it should be similar to the other chips I've worked with. Check Motorola's web site. They should have a cross compiler and a manual.

I finally updated my web site to include my robot project.

Been a while since I posted anything. The hollidays have been a very busy time both at home and at work. I pray everyone enjoyed the holliday season. I'm taking a long weekend for new years, I'm planning to update my web site with some pictures of the robot.

My robot project is progressing very well. The motor deck is about 80% complete mechanically and about 20% complete software wise. The CPU, H-Bridge and display are complete. The chassis is also complete. I still need to add hardware for shaft encoders and a line follower. I've put together a software routine that tests the hardware. The test routine isn't fancy but it confirms that the CPU, H-bridge and displays are working; it also makes the robot take off in a straight line, then stop, then take off again. I'll put a short video clip of it on the web site.

I've started planning for the control deck and sensor deck. The motor deck uses a motorola 6808 8-bit processor. It will take commands from the control deck and return data from the line follower and shaft encoders. By breaking the robot into separate decks with multiple processors I get to off load service routines from the main processor on the control deck. The control deck will have a single motorola 68010 processor. A serial port on the control deck will allow me to download and upload data to a PC or handheld device. The sensor deck will have a 6808 that processes commands from the controll deck and returns data from various sonar and IR senors. I'm planning on placing three sonar units on servos. A second 6808 on the sensor deck will probably be used to handel the PWM to the servos.

I'll put detailed plans, schematics and source code on my web site as the project progresses.

Made some more additions to my web site. The DMC Display project section is complete. There should be enough information to enable someone to implement an Optrex DMC Display in their project. I've included a user's manual, sample source code and a schematic for interfacing the display with a 6808 micro. I also corrected an oversight in the 6808 Bench project. A freeware cross complier and user manual are now available for download.

Hope everyone has a happy Thanks Giving!!!

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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