A bit of History

The_BAS_BoysA rogue’s gallery from Steve Goldman’s surprise anniversary party around 2003. Left to right, Eric Teagarden, Don Parce, Steve Goldman, Bob Leivian, and Pete Soper.

  • Eric – Business Application Systems, IBM, SAS
  • Don – Data General, Business Application Systems, SCI Systems, Foundation/Encore Computer, Sun Microsystems
  • Steve – Motorola, Texas Gulf, Business Application Systems, SCI Systems, Foundation/Encore Computer, Sun Microsystems
  • Bob – Data General, Business Application System, SCI Systems, Motorola Research
  • Pete – Data General, Business Application Systems, SCI Systems, Network Products, Foundation/Encore Computer, Sun Microsystems, Apex Proto Factory

Very accurate digital clock

 

 

 

ex-station-clock

A recent discussion of clock/calendar chips on one of the local email lists coincided with me reminding myself that I own a very decent clock with respect to drift.

I’m taking my amateur radio station apart (hadn’t turned the radio on in two years despite the sunspots peaking again: a very clear indication of my remaining interest in this hobby). I just moved the station clock indoors. It had been in an unheated room and I’m sure the time hasn’t been set in at least three years. The temperature went up and down constantly out there, to the upper 30s in the winter and upper 80s in the summer (the volume of air in the surrounding barn levels things out). Anyway, I just set the clock to EST and had to fix the minutes: off by two. So figure it was off by 179 seconds after 36 months. That’s 2ppm, what would be considered extremely good in a clock calendar chip such as the DS3231. All kidding aside, Radio Shack makes some decent stuff!

My North Carolina Home

Since moving here in 1977 I’ve found North Carolina to be an interesting place to live, but occasionally in the Chinese cursing sense of the word “interesting.” I won’t enumerate all the adventures that have seemed to be more common in North Carolina, but I recently got a reminder of one:

SAMSUNG CAMERA PICTURES

This is a juvenile (perhaps 15″ long) Copperhead snake in the middle of the garage.

Nordson EFD Solder Paste

SAMSUNG CAMERA PICTURES

A very nice treat from the PCB Carolina show last week was this set of samples from Nordson EFD. With Freescale FXOS8700CQ magnetometer/accellerometer chips and a Sparkfun Heaterizer XL-3000 on the way I need to get with it, get a PC board design off to OSH Park and prepare to use small SMD components. The Heaterizer is a stop gap while my hot air tool budget catches up with desire, and I’m hoping to get some lessons from a friend with professional equipment. But with this top quality solder paste I think I’m approaching critical mass. Thanks to John Conti of Nordson EFD for the technical info and support for my modest goals.

Even if you’re not interested in the Sparkfun $10 hot air tool you might find the instruction manual fun to read. But seriously, folks, this surface mount tutorial at the Sparkfun site makes it clear that individuals inexpensive tools can join in the fun.

UPDATE FROM 2021: The SparkFun Heaterizer was incapable of surface mount soldering. I ended up using a cheapo Chinese oven until I could modify a convection oven with interior hi temp reflective material and thermocouple/microprocessor control for proper heating/cooling profiles to do surface mount soldering. The oven is inside a decent fume hood with exhaust air out a flue for safety and to avoid any odor problems. The proper hot air tool came along too, but I still find it best to apply paste with a stainless steel stencil from OSH Stencils and use a reflow oven for professional level results, with the hot air tool for rework or the occasional expedient operation. Finally, the FXOS8700CQ is EOL and last possible purchases will be at the end of 2021, so time to find a replacement. A client and I are investigating the ST LSM303AG as an alternative. It isn’t lacks the capability to interrupt on magnetic vector magnitude events but the price is right!

One Sneeze Equals Hours of Picking Up

402sAtCarolinaPCB2013

This is a little plastic jar containing size “402” surface mount resistors. These resistors look like they belong in a pepper shaker. They were at a booth at PCB Carolina last week and there was a contest to guess how many resistors were in the jar. I guessed 10k, and that was good for a top ten finish, but the correct number was 10,863.

Wally Bot sweeps competition at Efland-Cheeks Elementary Robot Camp

WallyBot

 

Today I mentored Trey and Tyler, two elementary school children in a “robot camp.” They built a robot with Lego Mindstorm NXT 2.0 components and it swept the competition and then came out on top in a free for all battle between all seven robots. The robots fought “sumo style” within a roughly four foot diameter circle until all but one robot was forced outside the circle or disabled.Trey drew Wally’s face (his eyes are an ultrasonic rangefinder). The front ramp/scoop was very stiff and tended to make Wally’s wheels really dig in, frequently flipping the other robot if it could catch it from the side. In the final round of the main competition Wally and his opponent were locked together for almost the full two minutes (that would have made a tie), but Wally could push the other robot forward in a slowly wandering ellipse that eventually passed outside the ring, tricking the other robot into backing up (which put it completely outside the ring). Very exciting!