The Microship Status Reports

Microship Status 1/20/94 by Steven K. Roberts

In This Issue:

Progress On Mcs Network
Other Updates
A good, busy day in the lab. Today was the meeting of the ECE class of 11 people working on FORTH controller projects, and took the form of a very spirited discussion about data structures, protocols, and the specifics of everyone's machines. It's getting interesting...

Progress On Mcs Network

Most of today's hands-on effort involved the multidrop network, with Michael Bream, Chris Tuft, Dan Yang, and me working together. Michael distinguished himself with some very clean packaging work (he has spent years installing car stereo, cellular, and security products as well as doing various other fabrication projects, and it shows). I recommend that anyone who's working on Microship electronics projects without prior hardware experience spend some time with Michael to pick up some pointers on cabling, packaging, soldering, and otherwise doing hands-on electronics... it will pay off.

Anyway, the task at hand was to configure and bring up the serial board on the Hub, make the Hub's network interface box, and cable at least one node to the net. All of this takes an amazing amount of time, requiring the hacking of not-quite-right connectors, finding cable, and debugging the whole mess -- a task complicated by the garbage RJ-11 junction boxes we bought by mail order from All Electronics. About half of the insulation displacement connections turned out to be intermittent or open, easily explaining why they were so cheap on the surplus market. Now we have to pay with time instead of money, soldering all the connections by hand. <sigh>

Results? We're not there yet. A FORTH node is now connected physically to the Hub, and we can see data flying around when we write a transmit loop, but we have not yet been able to see a receive data flag indicating flow in the other direction. Once we get that going and write some basic tools, we'll start programming the on-chip EEPROM in each board with its assigned net address, and, hopefully, find a way to install some non-volatile Easy-A code so a crashed node won't take down the whole network. Ah, learning curves...

By the way, a little aside for anyone working with the Hub development system: the Power One 5-volt supply on the chassis can go into crowbar mode when briefly shorted, and will STAY that way until the unit is physically unplugged from the AC line and allowed to cool.

Another thing about power: I'm installing screw terminals on the FORTH boards, which can be wired backwards if you're careless. PLEASE don't do this, but if you do, I'm also installing a 1N4001 protection diode on each board, reverse-connected across power. This will smoke profusely while causing severe embarrassment and loss of style points. Please be VERY careful with all wiring if you are doing any kind of hands-on work here! (The looped diode anode lead, by the way, provides a handy ground point for a scope probe.)

Other Updates

I'll ask TJ Tyler and Jeff Klompus to write a whole report about this when they're at a good checkpoint in the structure project, but today they spent about 3 hours with my hot glue gun and a bunch of toothpicks left over from mini hot-air balloon projects. There is now a miniature model of the Microship internal frame (rev 0.1) that allows visceral analysis of stress modes. While we all love CAD and other design tools, it really helps to make models that can be handled and passed around -- it's a tremendous aid to visualization and understanding.

Agnes shipped copies of recent media coverage to all named sponsors today, bringing us up to date with this never-ending but pleasant task. The latest addition to the media collection arrived just in time today -- the Winter 93-94 issue of _UCSD_Perspectives_, mailed to alumni and contributors, containing a good 3-page article about the Microship and BEHEMOTH.

Agnes is also working on the rather daunting task of figuring out how to match the growing project list to available human resources. Those of you who have submitted questionnaire responses are already in good shape -- if you have not done so and need a copy of the 10 questions I circulated to all student volunteers before Christmas, please email her directly <adeguzma@icse3.ucsd.edu>.

I spoke with Kirk Elder and Bill Lee, two wizards in high-efficiency electric motor/generators. The next step in thruster design is to track down information on units from "Unique Mobility" in Colorado -- reputedly up to 98% efficient with sumerium cobalt magnets, and the motors of choice for most of the solar race cars. Kirk likes (and sells) GE series-wound traction motors; Bill sells variable reluctance and prefers those. Much of engineering lies in sorting out the varying opinions about all choices...

We'll have a very welcome guest in the lab this weekend -- Bill Brown, WB8ELK. He's the former editor of _73_Magazine_, and is a consummate hardware hacker with years of experience in ham radio, video, intrumented high-altitude balloon, voice IDers, and control systems. I'm sure some new ideas will be circulating within the next few days.

Enough for now -- I'm going to go pound the FORTH keyboard and see if I can get the Hub talking to one of the remotes! I need a win before bed...

Cheers, Steve