MightyOhm

If you could recommend one book to a total beginner who wants to learn how to program in C, what would it be?

It shouldn’t be microcontroller-specific (more general is better), but it does need to make sense to someone with zero programming experience (in any language).

(Myself, I started with K&R, although I had some experience with BASIC (on the C64 and Apple II), Logo, and shell programming before that.)

When I buy a piece of electronic test equipment, the first thing I do is turn it on and see if it works.  This is the moment of truth: was that awesome eBay find the killer deal I thought it was?  (Hint: If it’s missing case screws and came with no packing material, probably not.)

Sometimes, everything works out and I have a shiny new piece of test gear for bottom dollar.  Often, things don’t work out quite as expected.  Luckily, test equipment is often made to be fixed.

To fix it, I need a service manual.

This means that with my luck, more often than not, the second thing I do is try to track down the service manual for my new semi-functional piece of test equipment.  Even if the it’s not broken, I’ll usually try to get a service manual anyway; often the service manual doubles as a user manual and I need to figure out how to use special features, find specs, etc.

If you find yourself in a similar situation, here are some tips for finding test equipment manuals:

1. If it’s a fairly new piece of test equipment, chances are the manufacturer will have a manual on their website, usually in pdf format.  For example, Agilent has lots of manuals online, but unfortunately, anything over 20 years old is probably not listed.  Other vendors are better about archiving old manuals.  I have had very good luck getting old Fluke manuals on their website.
2. Google is your friend.  Are you feeling lucky?  Some manuals are easy to find, like this one for the HP 3312A Function Generator.    The first link that isn’t an ad goes right to it.  Easy!
3. There are several free service manual repositories on the web.  These can be very hard to find when you need them (spammy links from manual vendors sometimes derail your search).   I have started keeping track of free sources for test equipment manuals on the wiki.  If you are looking for the manual for a fairly common piece of HP/Agilent or Tektronix gear, there’s a pretty good chance you’ll find it for free on one of the sites listed.
4. As a last resort, consider paying for an electronic copy of the manual.  Beware of vendors who are simply downloading readily available manuals for free and selling them to you.  Use eBay with caution.   The wiki now includes a list of reputable service manual vendors.  The only vendor I have used is Artek Media.  They have very reasonable prices and great support.  At $5-$10 a pop, sometimes it’s easier to just buy the manual than scour the web for hours, so it’s nice to be able to trade laziness for dollars.

Usually by step 3 I have the manual I need, so I rarely have to pay for a copy, but it’s nice to know that most obscure manuals can be had for a few dollars.

I hope these tips keep more old test equipment running – remember they don’t make ‘em like they used to!

If any readers have more sources for manuals to add, please leave a comment or add them to the wiki.

Over the holidays I had a chance to visit Ali’s Surplus Stuff in Sacramento, CA.

This is my kind of place.  Surplus electronics piled from floor to ceiling.  Lots of oscilloscopes and useful stuff mixed in with bizarre industrial equipment.

Lots of cool rack-mounted equipment here.  Lots of push-buttons too.

Need a random computer-related printed circuit board?

My recommendation for places like this is always to come to the counter with the biggest pile of stuff you can carry and haggle on a single price for everything.  You’ll end up paying a fair price for one or two big items and getting the rest thrown in “for free”.

Here’s what I went home with: HP chart recorder, some IC sockets, webcam stand, random RF module, and some kind of monitor shutoff device from back when ‘green’ was just a color.  This is a remarkably small pile of stuff given what was available, but I knew I would have to pack all this into my checked luggage on the flight home.

This was my first visit to Ali’s, and I came home really impressed.  I can’t think of a better place to find surplus electronics junk in the Sacramento area, especially now that HSC Electronics on Auburn Blvd. is gone.  I also feel that if you are looking for used industrial and test equipment, Ali’s has a better selection than Bay Area shops like Weird Stuff.  I will definitely be visiting Ali’s again the next time I’m Sacramento.

Ali’s Surplus Stuff is listed under Sacramento Area on the resources:surplus page of the MightyOhm Wiki.  Whew!

I’ve been making some changes and additions to the MightyOhm Wiki over the past few days.

To complement the awesome list of surplus electronics shops, I started creating wiki pages for the various projects I have previously documented on the blog.

Last night I added a list of cheap PID controllers to the wiki page for my DIY PID-controlled Soldering Hotplate.  (Backstory: the PID controller on my hotplate quit working this week and I’ve been shopping for a replacement!)

I have also  been adding more information to the PCB resources page, including where to order cheap solder paste stencils and resources for making test fixtures.

More to come…

Laen of DorkbotPDX has been running a PCB proto service for some time now, and I finally got a chance to try it out this month.

The pricing is simple.  For 2-layer boards, it’s $5 per square inch for three (3) PCBs, with no setup charge, and shipping is free.

The tunaround time is typically 9 days + first class mail shipping, which ends up being just under two weeks total fom PCB release to delivery in Austin.  This is pretty good for a group order, and signficantly faster than BatchPCB (based on my experience).

The only downsides that I am aware of are:

• PCB orders only go out once a month, unless there is enough demand to justify a 2nd run.
• If you wait too long, the panels can fill up.  Again, if there is enough demand, sometimes a 2nd panel can be added, but don’t count on it.
• The soldermask and silkscreen can be any color (and you don’t get to choose!)  BatchPCB at least guarantees the standard white/green.

4-layer boards are available as well, but at a higher cost ($10/square inch) and less frequent intervals.

Entries for the next PCB order are due on October 25th.  The more orders Laen gets, the more likely he is to continue the service, so if you have some designs you’ve been thinking about but have been put off by expensive PCB costs, finish them up and get some boards made!