Minutes of the PARTS meeting on October 4th, 2003
President Pete Skeggs opened the meeting by announcing that the topic for the monthly education session would be etched circuit board design capture systems. There were a few business items that needed to be taken care of first.
Pete proposed club dues for active members, an idea that the PARTS executive team has discussed and decided to ask PARTS members to approve. Dues would be $12.00 per calendar year, collected once a year in advance. Persons joining PARTS mid-year would pay pro-rated dues from the month of their second meeting (when they are officially eligible to join PARTS) through the end of the calendar year. Pete showed a new membership application and stressed the information collected would not be released to anyone outside of PARTS. Among the current PARTS members in attendance, the assessment of dues passed with a vote of 17 to 0 .
The next item of business concerned the dollar amount of a PARTS scholarship and/or donation to the PSU engineering department. Following a brief discussion of our relationship with the Electrical and Computer Engineering department at PSU and the student chapter of the IEEE Robotics and Automation Society, we decided to provide two separate donations this year. The motion for renewal of a $250 scholarship for use by a PSU engineering student was passed with a vote of 18 to 0. The motion for a donation of $200 to the Robotics and Automation Society for equipment purchases was passed with a vote of 19 to 0. (The seeming discrepancy in the number of votes cast was due to late arrivals at the meeting.)
Pete reminded attendees that elections of PARTS officers for the next two years would be held at the November meeting. Three of the four current club officers (Pete Skeggs, President; Warren Leach, Vice President; Doug Arnold, Secretary) have already stated their intentions not to run for re-election. Dana Weesner, current PARTS treasurer, intends to run for re-election. Pete asked for an indication of interest among club members interested in being elected to office. Paul Burkey, Tim Weaver, Monty Goodson and Larry Geib indicated their willingness to run for Secretary, Vice President, President, and Treasurer, respectively. Brad Lewis indicated hed be willing to learn about accounting and assist the treasurer. Pete asked each of the current officers to write a description of their duties for their successors.
The meeting continued with Dan Gates showing the torso of his walking robot, S.A.M.M. (Servo Actuated Mechanical Man) . Each leg has six degrees of freedom, and the robot will contain 22 HiTec HS645MG servos when complete. Dan is using the New Micros ServoPod controller, and programming in FORTH. The robot is able to walk using static balance only at this point; Dan plans to add two model helicopter gyros, an accelerometer, and four foot pressure sensors to implement dynamic balance. He will tap into the servo potentiometers for positioning feedback. Dan plans to enter SAMM in a stair climbing competition. The outer structure of SAMM is made of 1/8-inch acrylic plastic, cut on a band saw or scroll saw, with edges finished on a belt sander. Dan said that the torso is already getting crowded; moving batteries to the legs would relieve the crowding, but then the legs would be too heavy for the servos to lift.
Steven Minichiello presented an educational session on schematic diagram capture. Steven said that schematic diagrams should be complete enough so that someone else could figure things out if they had to. Stevens eleven-point process flow is admittedly more rigorous than some of the other systems he has seen used.
- Conceptualization this is "back of the napkin" logging of ideas or approaches
- Specification describe the required and desired functionality
- Parts Selection if specific devices are required, list them
- Library Creation parts libraries supplied with board layout software are sometimes limited or inaccurate. Use manufacturers data sheets to add components, and dont hide or omit any pins on devices.
- System Partition segregating functions can make net list checking more thorough
- Design Entry add callouts for net list connections and off-page connectors
- Design Checking this function is usually provided by the design tool
- Design Optimization add new features, de-coupling capacitors if needed
- Documentation include a cover page, revision history, block diagram
- File Output software generates artwork for etched circuit board creation
- Reiteration supply improvements to the design, because no design is perfect
Steven suggested that a written description of the project can often help you keep in mind the more practical aspects of product design. He said that there are quite a few CAD (Computer Assisted Design) and EDA (Electronic Design Automation) companies in the Portland area including Cadence and Mentor Graphics, developers of two high-end systems. Altium is the third major company in the top tier. Steven shared a "family tree" showing the lineage of most of the popular systems available today.
Steven said that ORCAD is more of a spreadsheet-driven program, while PROTEL is more menu-driven. Eagle is available for free, but is limited to boards a maximum of 4" in any one dimension, and single-sheet schematics; the commercial version of Eagle costs $400. Some open-source tools are available, but bug fixes for open-source products may be difficult to obtain. Steven said that most EDA packages (with the exception of ORCAD and PROTEL) are not able to import data from other products, so selection of a tool for the long term is important. Steven recommends Electronic Design Automation, by David Pellerin (published by Prentice Hall PTR) as a good explanatory text on schematic design capture.
The Show and Tell portion of the meeting began with Pete Skeggs, who passed around a copy of Rodney Brooks latest book, Flesh and Machines How Robots Will Change Us. Pete has been working on some open-source projects: an email list server, and a database-driven digital asset management system designed to track digital photos of student work. The tracking system will produce reports by student, by educational goal, by use of the photo in a report, etc.
Kyle asked if anyone had the first issue of PopTronics. He was trying to find an article he remembered reading several years ago about speech recognition systems. He would like to build a voice activated assistance device for a quadriplegic person. Suggestions Kyle received included finding a more recent article, because the hardware in the old article would be obsolete by now anyway. Someone reported that Oregon Graduate Center has a collection of speech tools. Someone else suggested the Evolution Robotics mobile platform with both speech and vision systems as a possibility. Still another suggestion was to couple a pc running speech recognition software with an X-10 home automation system to control appliances. Brad Lewis said that he has experience with a phone dialer and X-10 modules.
Paul Burkey reported that the latest issue of Popular Science contained an article about a robotic human face.
James Davis proposed that PARTS produce a directory of member services, so that when someone is looking for help (with motor drivers, or circuit board design, for instance) they would know who has experience and could help.
Another attendee (sorry, I didnt catch your name) was searching for a source of servo lockwashers to keep control horn retaining screws from working loose. Tammies Hobbies was suggested as a source of small lockwashers. Steve Hampson suggested using a drop of blue Loc-Tite.
Tim Brandon reported that the Portland State Aerospace Society (PSAS) had a September 28th launch of their latest rocket design (the "ultimate flying robot") in the Black Rock Desert of Nevada. The rocket broke up during ascent as it passed through the sound barrier. More details are available at http://www.psas.pdx.edu.
John Hurley reported that he got his Kevin Ross HC12 board with LCD display to work. He wants to use the processor for DC motor speed control.
Ron Tsur asked if anyone had access to an SMD soldering/repair station.
Eric Stewart reported that the new Mark Tilden-designed RoboSapien toy would be produced by OWI, and should be available by the end of the year. Eric said there are videos of RoboSapiens on the web, that it is designed to be hackable, and should be priced at $80 to $100.
Steven Minichiello showed a copy of the latest issue of Scientific American with an article on the physics and applications of Nitinol "muscle wires".
Tim Rohaly showed his prototype BlueTooth wireless serial cable. He said that current versions cost about $300, and he hopes to be able to produce a wireless serial cable for about $50 total system cost; the cost of components in his prototype is still about $150. The chipset Tim is using now draws about 60 mA when active, but a new TI chipset promises lower power consumption. Tims device should eliminate the need to put intelligence in the controller.
Shawn Marshall showed the clamshell case artwork for his DVD of PDXBOT.03 . He said the DVD contains 16 chapters, making it easy to get to selected competitions.
Brett Nelson showed the latest version of his robotic arm components. When initialized, the grappler opens and then closes to calibrate itself . He showed his joystick arm controller built from a Sony PlayStation control unit . He got the idea from an article he read in Nuts & Volts magazine. The controller has its own 8-bit AtoD converter; Bretts demo displayed the digital values that represent the joystick position.
Brad Lewis brought the new PARTS library of equipment available for checkout to PARTS members. Brad showed the parts, controllers, and personal computer available for checkout. PARTS members have offered an OEM BS2 board, and a Rick Farmer PIC board for the library. Brad also had scraps of plastic for making parts, provided by Bruce Filener.
Monty Goodson showed his new circuit board from Advanced Circuits . His board layout included 420 small circuit boards, and was created with a PERL script to panelize smaller boards into a single-panel Gerber file. His board included quite a few of his new "Prox Dot" IR sensor boards.
Steve Davee recommended the new book "Code Name Ginger" about the development of the Segway scooter. He said it is perhaps the best book about development of a new technology product since Tracy Kidders 1981 book, "Soul of a New Machine". Steve highly recommends on-line reservation of books from the Multnomah County Library system.
Tim Weaver showed his new LandShark circuit board. It features eight of Montys "Prox Dot" sensors, and should give LandShark even better awareness of where its opponent is located at all times. Tim referred attendees to the PARTS website so they could read the article comparing Solo and Goliath.
Karl Boe described riding a Segway scooter recently. He reported that until he became accustomed to the motion, the scooter had a tendency to porpoise. He reported that he was surprised at how far back he needed to lean in order to stop. Karl is building an engine control computer that is based on the Kronos Robotics DIOS chip for use in a Plymouth Valiant. He reported that Kronos president Michael Simpson has designed a new Aries controller board for the MkIII chassis, but has been unable to get a response from anyone here in Portland who he has contacted about selling the board. At this point, it is extremely unlikely that Kronos will be a sponsor of PDXBOT.04.
Warren Leach reported that he has been designing a data logging project around the Atmel Mega128 processor, and is really impressed with its capabilities.
Daryl Sandberg showed his next-generation mini-sumo robot chassis . He used a brass plate to hold his motors, and will mill his robot body out of a block of Delrin . Daryl has decided to use high-current Li-polymer cells to power his robot, and he bought a nice microprocessor-controlled battery charger to recharge his cells . The charger is intended for recharging R/C electric airplane batteries at the flying field. Its powered by the vehicle battery with two large alligator clips; the charger has an inverter that can generate up to 24 volts to charge higher-voltage battery packs. Daryl added a Radio Shack box with alkaline cells to power the charger when hes not near his car.
The next PARTS meeting will be Saturday, November 1st at 10:30 am in PCAT 28.