Chuck's Robotics Notebook
By Chuck McManis
President of the Home Brew Robotics Club of Silicon Valley
Latest Update: December 10, 2002
My name is Chuck McManis, welcome to my notebook!
I am an engineer by training (BSEE from USC) but mostly what I do at work is design very large systems and write software. To keep my hardware chops relatively useful and because there is nothing quite so exhilarating as a program crash, especially one that actually does damage to the computer running it, I dabble in the robotics hobby. I've been doing this for about 15 years now and boy have things changed! Robots in 1985 were lucky if they had a computer on board, usually connected by a flakey wireless link. Today you can put a cheap laptop on a platform for about $250 that is more powerful than most minicomputers and some mainframes back in the previous century.
One of the things I encourage people to do when they begin their journey in robotics is to keep a notebook. The notebook serves as journal and knowledge repository for the aspiring roboticist. My favorite notebooks are the model 43-648 Computation Notebook printed by Dennison Stationary Products Co. They have a 4 x 4 graph paper and each page is numbered. Another good one is the Design and Computation Book by the Laboratory Notebook Company (form WW-200-100). The Design & Computation Notebook also has a 4 x 4 quadruled page with numbers but also had a cover page with a description for the contents. Remember to leave the first couple of pages blank and then later use this as an index for pointing forward to interesting pages.
If you're really lucky, you can order lab notebooks from the Eureka Lab Notebook Company. These are the best notebooks as they are hard cover, already have the table of contents in the front, and can be customized to your liking. My favorite is green quadruled pages, embossed with "Robotics", and numbered. Sweet! (but pricey at $30 each)
Anyway, this then is an online snapshot of my notebook, and what with the web and all, should be a good place to store and share information.
The online notebook is divided into several sections that collect different kinds of things. Mostly circuits, projects, controllers, etc. Generally I've built everything I write about however errors do occur in transcription so if you see one please mail me about it so that I can fix it!
At the bottom of this page is a Bibliography of books I feel are worth the incredible price that these things go for these days.
This is where most of the updates occur, various projects get information added to them, or I add a one pager describing them. Pretty much there is something new here every week or so. On this page you will find over a dozen projects that I've done at least a 1 page write up on. They span the gamut from my widely read H-bridge project to the mundane Jumpers project. Be sure to check out the Gizmo project as well.
My FPGA Journey
I've written up some of my experiences with FPGAs and in particular the one from BurchEd and XESS. This effort slowed down while I was distracted by BattleBots. Fortunately, I'm getting the boards out of storage so that I can start work on a Soft Console. The idea being to have a I/O console that can be the front end for a number of FPGA projects.
Things of Interest to PIC Users
I like the Microchip PIC processors. With the latest flash based chips like the 16F628 they are nearly ideal little microcontrollers for just about anything I do.
Tools I Use
You can't build things without tools, and unfortunately the tools are often the most persnickity of things. This link takes to you some pages where I've written up my thoughts on the tools that I like to use.
This section of the notebook covers interesting circuits that I use a lot in various robots and other projects. It isn't comprehensive but the basics are here. (it is also getting the least attention at the moment!)
This section of the notebook covers some tutorials I've written on various Robotics topics. Check out the H-Bridge tutorial...
One of the things that is really different today is the wide variety of micro-controllers available. Generally they come in three flavors:
- Boards designed to run robots, either for classes or products.
- Boards designed to embed in lots of different systems.
- Manufacturer evaluation boards.
This section describes some of the robots I've built. When possible I've included pictures.
- KillerB - Our entry into TLC's Robotica television show and a Battlebot
- ARBE-1 - A very simple 'bot for beginners (attempt at a club intro-bot)
- Sherman - A robot with ears, uses the Rug Warrior board.
- Xavier Cougar - Based on the Wild Cougar R/C truck model
- Dino - "Meal on Wheels" was a "prey" robot for the Cougar
- RoboTank III - Something that moves and can pick things up (not!)
Useful (Useless?) Information
Once upon a time the BASIC Stamp was a neat new controller. I bought several and have used them in a few robots and I keep one on my bench to generate test signals. I also got curious about how they stored what they stored and spent some time decoding the BASIC stamp.
Here is another interesting tidbit, on the Futaba FP-R113iJ (otherwise known that PCM version of the PCM1024) generates it's servo signals for all channels at exactly the same start time. So to measure all three channels, you need only wait for the starting edge on any one of the channels, and then track the falling edge of each of the three channels.
I've got a Links Page up with some useful jumping off points.
A feedback diagram for a balancing robot.
A Bibliography of Sorts
You really can't "figure it out all on your own." That just isn't possible, also there are about a zillion books on electronics and software and mechanics etc. So I'll try to keep a list of my favorites here so that you can build a "Mechatronic" library of your own:
"The Art of Electronics" 2nd Edition by Horowitz and Hill. This is truly the Bible for electronics. It starts with a chapter on basic theory and then moves briskly right into the good stuff. This will be a reference for you for the rest of your life so don't skimp and get the student guide too. That way you can check your answers when you do the exercises.
"Power Electronics" 2nd Edition by Mohan, Undeland, and Robbins. Published by Wiley. I can't say how important it is to have this book if you're going to be building H-bridges or other high power robotic interfaces. This book has it all, chopper drives, FETs, BJTs, how to figure out thermals, design transformers, etc. I wish I had had it at the start of my big speed controller project.
"Mobile Robots: Inspiration to Implementation" by Flynn and Jones. Published by AK Peters. This is a classic because it tells you exactly how to go from thinking about something to actually implementing it. There is a good description of software here and there are good chapters on basic construction techniques. You'll probably want a Lego Mindstorms or a Rug Warrior to go with it though to run through the exercises and watch what they do.
"The Designers Guide to VHDL" by Peter Ashenden. This is an excellent reference for VHDL and if you're going to do FPGAs in VHDL then you have to get this book.
The Logo Story
Because I'm a slow learner, it has taken me about 8 years to put together a robotics logo that I'm happy with. Well suffice it to say, this is it! The one true robotics Logo! Capturing in a single design what it is to be a robotics experimenter, hobbyist, scientist, and entrepreneur. Programming, Mechanics, and Electronics all combined around a great idea to form a complete whole. Yup, that's what it says : Robots.
Roger Gilbertson and I were tossing around ideas for logos at an HBRC meeting a long time ago. We wanted something that combined the essence of robots which is really a triple discipline activity. This even has a name of sorts, "mechatronics" but that fails to capture the programming aspect of it. Anyway, I wanted to represent each of the disciplines used in robots in such a way that you could make it into a patch, further the patch could be worn in such a way that your "best" discipline would be on the top, or if you were good in two disciplines you could wear it with two sharing the top spot. That way during the "random access" time of the meeting you if you were looking for help with programming just look for folks with the programming section on top. Neat huh?
I've sketched out over a dozen different ideas, flow charts, transistors, etc. Roger has too, some of them are in his catalog (see page 4 with the icons for hardware, electronics, software, and dreams). But they didn't seem to jell. Well Bill Benson, another club member drew something similar on a piece of paper and it was the missing pieces. Software as ones and zeros is pretty universal (flow charts are much too dated) and he had a transistor but I upgraded it to a FET, and of course there's never been any doubt that a gear would represent mechanics. To that I added the "great idea" (the light bulb in the middle) the is the center of it all (Roger's "dream" fills the same sort of space) and voila' a Robotics Logo.
--Chuck McManis, August 2002.