On Home Projects as a Reentry into the Job Market

Those homde-made ICs are logic gates -- not quite up to the CDP1802 level. :-) Jeri's unique for doing this completely at home, but note that until quite recently many universities still had older generation IC manufacturing abilities: I know a guy who finished college in the mid-'80s, and in one of his lab courses they were also replicating standard logic chips, all the way from "bare silicon wafer, some dopants, and a furnace" to "packaged, finished part." These days universities usually just have the job done by MOSIS or a commercial research partner if said partner has a fab of their own (e.g., Triquint, IBM, etc.).

(This evolution with how universities build ICs has largely followed PCB construction: There are a few die-hard schools that insist on cutting and/or etching boards in-house, still, but the majority of them today use one of the inexpensive commercial fabs given how much better the quality is and how inexpensive the pricing has become.)

I actually designed the original SDRAM controller in her "Commodore One" there -- she had it working with SRAM, but figured that SDRAM would be better (and I concurred) given how much cheaper it was. I had just finished a very fancy SDRAM controller for work, so I was able to crank out the simple-minded one she needed in a few days after work and handed her the VHDL when I was done.

Of course, after that it was undoubtedly modified by many parties. Jens Schoenfeld in Germany

played a significant part in helping get the design from the prototypes stages to an actual product as well. In fact, there was a bit of a spat between them in that he thought he had purchased exclusive rights to use the design, but Jeri then also used it at Mammoth Toys for the "computer in a joystick."

Jeri's done an exceptional job of succeeding despite very humble beginnings. I think much of this can be attributed to her tenacitiy -- once she decides she wants to do something, she'll keep at it day and night until it's done. She spent years hounding various former Commodore engineers for schematics, chip layouts, and other historical information they had that she wanted to learn. She's a very sociable person by nature, always wanting to learn.

---Joel

In '74 students were doing good to make NPN transistors. ;-)

We used a lathe to cut circuit boards. AIUI many now use the "CNC router" style prototyping systems. We have one of them at work, too, but it hasn't been used much. It's a little crude.

Just use the FPGA's macro tool. ;-)

Sounds like a fun person to be around.

Hi Keith,

Not bad, not bad at all. :-)

CNC routers are great if you need something more or less immediately... or if for some reason you're going to need a lot of revisions to the PCB before you really know what you want... but these days, if you can wait a week, not only do the commercial guys give far better results, but in most cases it costs less money overall if you have to be paying someone's salary to do it. (We have a pretty nice LPKF machine, but it really doesn't get much use.)

Do you guys do any pick & place/reflow/assembly there? We have a manually operaeted pick & place machine and a small reflow oven, which is convenient at times.

[SDRAM controllers]

Ha... this was back around the turn of the century, and while I think Xilinx was just starting to have such macros, they sure weren't considered trustworthy! Same with FIFOs at that time -- we had written our own, which "just worked," whereas I remember in the service pack notes how it seemed they were always fixing various empty/full synchronization problems with the silly things. (That being said, I was always impressed with Peter Alfke's abilities -- he clearly knew the parts inside and out, and knew how to make them work reliably. But not everyone there shared his talents...)

These days I would at least take the macro generator for a spin, I suppose. I don't want to become like one guy we had at work then, who didn't want to trust that the synthesis tools could implement addition efficiency, and spent several weeks writing his own basic arithmetic routines... only to find that they performed more slowly they the synthesizer's built-in functions, since the optimizer wasn't able to do as good of a job without "understanding" the overall function of all those 'flops and LUTs he was instantiated one-by-one...

(On the other hand, around the turn of the century was also about the point where you finally could trust the synthesis tools to know how to *multiply* -- I remember people doing a lot of testing, and *finally* the implementations were starting to be reasonably efficient things like Wallace multipliers...)

Oh yeah, she certainly can be!

---Joel

Ditto. We are rarely pressed for time on prototypes and when we are they want it "shippable". Yeah, right.

Sure. We do all our own assembly. Our reflow oven is kinda crude (only five-stage), but other than that the stuff works very well. They're talking about getting an eleven-stage oven but I think the holdup is trying to figure out how to slip one into production without a huge risk of missing ships.

Hint: They still aren't. ;-)

Xilinx' FIFOs worked very well for me, about then. I didn't use the core-gen, or whatever they call it, but I did use their primitive.

I did pretty well implementing wide logic (things like comparators) using Xilinx' fast-carry chains. I could certainly beat Xilinx' synthesis. I checked again a couple of years ago and they were using the carry chains for wide logic. In '98 or '99 Xilinx' synthesis was so bad I bought Synplify Pro.

Does your current reflow oven have a profile for pizzas? ;-)

Citing "just to get back into the swing of things" I would say "no". If you *know* how to do "X", then doing it just prior to *RE*-entering the work force means little to me: "Was your skillset *that* weak that it couldn't survive the hiatus? Or, have you been *idle* for that long that *I* should be concerned as to whether your WORK ETHIC may also have been compromised in this time period??"

If, OTOH, you were *ENTERING* the workplace, I would *carefully* look at your choice of project and *approach*. I'd much prefer to see an applicant who has the ambition and drive to *attempt* something "on his/her own" instead of *buying* a solution. And, I would base much of my interview on dissecting the approach taken, decisions made a priori vs. during the effort, lessons learned, etc. Did the applicant *learn* anything from the effort (besides "how to make a whatchamacallit")? Is he/she likely to learn anything *here* -- or will he/she just rerun the same algorithm for a paycheck...

At the same time, this would work *against* an applicant (!). Too often, people fall into the hammer-nail paradigm and throw the same solution at *every* project with which they are (subsequently) faced. I see this a *lot* with the PIC crowd. EVERYTHING gets done with a PIC (sorry, but you are either distorting the needs of all of those "everythings" to *fit* your implementation *or* you aren't thinking of what you

*could* do with those everythings WITHOUT the "PIC constraint").

The hobbyist mentality qualifies you for a technician's job. It *may* qualify you for an engineering job *if* you can see past the hobbyist's mentality (cheap, do it with the tools on hand, minimize learning curve/expense, etc.). I want an engineer to be able to evaluate the needs of each assignment and tailor his/her solution to *those* constraints -- not just a rehash of the last project he/she did (which was a rehash of the project before that, which was a rehash... etc.)

E.g., I am currently working on deploying three very similar systems with three very different implementations based on the individual requirements of their application domains. On one, I use ~30

1GHz/1GB SBC's (P3's); another uses ~50 100MHz/512K SoC's; the third uses a mix of SBC's and COTS kit. The communication media vary from 10/100/1000Mb wired to wireless to ZigBee (i.e., very different data rates, geography and "reliability"/connectivity). One is modeled more like a NoW, another like a mesh; some loosely coupled, others tightly (including SMP).

Obviously, the software that rides atop these has to vary as well. The OS's are different in each application domain. Ditto with the network stacks, etc. Some are largely C/C++, others are shoehorned into ASM implementations.

An applicant that tried to use the same approach (hammer) on each (nail) would be (subconciously) telling me that he/she is focused on his/her *current* skillset and not the needs of the application(s). And, will fit the application to the skillset instead of the other way around. I.e., fearful of their abilities instead of confident in them. (So, why, as an employer, should *I* be confident in them??)

I want to see *focus* in a job prospect. Are they able to identify the important issues (e.g., "feeding their family", in your example) *and* do their actions "make sense" in meeting those issues (keeping in mind that my idea of "sense" can differ from theirs).

E.g., "I played Nintendo" while *waiting* for a job is not a "good answer" :-/

The problem with "hobbyist" projects is that they are almost always unstructured. This isn't how things (should!) work in the businessplace.

E.g., you can't just sit down with a vague idea of what you want to end up with and slug away at it until you get "tired of it" (which, essentially, is how these projects "end"). As an employee, I want you to be able to sort out what you are going to do A PRIORI to *reach* a particular goal WITHIN a particular set of constraints -- instead of just starting out and "hoping for the best". (i.e., how many hobbyist projects *really* meet their INITIAL stated goals? Where were those goals FORMALIZED??? How many projects just fizzle out when you get "too busy"?)

Given how easy it is, nowadays, to slap something together, I would dismiss most "projects". Unless you are *entering* the workforce (fresh out of school), it doesn't say much about your abilities. It *may* reveal how "frugal" you are, though: how much time are you willing to throw at a "pet project" instead of just

*buying* a COTS solution! (and, will you resort to a skimpy design approach to save the dollars that "doing it right" would require??)

E.g., the folks who throw a PC at *every* problem that comes along don't earn many gravy points with me. Yeah, I know you can make a TiVo out of a PC -- you can also use it to defrost frozen meats! I'm not impressed with *either* usage. :-/

Cool! There are people who advocate just such actions as "healthy" for the mind/soul and "regenerative" for vocational purposes (on the premis that only by "looking away" do the eyes see clearest).

Teaching is said to be the best way of *understanding* something. It is a remarkably effective way of sorting out ideas in your own head (assuming your goal is to *be* a good teacher). E.g., I spend a fair bit of time formally documenting things "for others" in an effort to sort them out in *my* mind before starting out on an undertaking.

Of course, if your friend's interest in math is not directly related to his/her career goals, this may not apply (as much).

I'm currently hiring for my company. A hobby in the field is big plus for me, especially for people with short work history. It tells me that they're in the art for passion, not just because of good job.

Getting from Wii to a working embedded system, however small, may show at least capability of learning. Not as good as a hobby, but a plus.

We're constantly doing projects where we do things we've never done before, so the learning capability is an absolute must in my business.

--
Mikko OH2HVJ

snip

Boy, it's nice to see someone in a position to hire saying that. I've seen all too many people who are trying to do something unique, yet can't gather the courage to go hire someone unless they've done exactly that never-before-done thing.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

We do assembly in-house either when time is tight or when the boards are simpler. We have some military products where, while the designs aren't particularly complex -- just a whole bunch of roughly the same circuit repeated over and over -- some boards end up being something upwards of a thousand discrete parts, and the techs really prefer not to have to sit down and pick-and-place that many parts manually... so those go to a contract manufacturer.

Same here (or maybe 6 stages? -- but certainly not 11).

We're planning on building an entirely new shop with a pretty fancy production line. It's been delayed due to the slump in the economy (customers delaying or cancelling orders), although it's now planned to break ground by the end of the year, which is pretty cool. (It is a bit cramped here right now...) There was talk about offering contract assembly services to help pay for all this if we don't have enough of our own goodies to keep at least one shift going every day year 'round; should be interesting to see how it plays out.

Ah, good to know!

We were using Synplify as well -- Xilinx was packaging FPGA Express (aka, FPGA Distress) at the time, and it was really quite awful -- worse than the free synthesis tools that Cypress gave you for their CPLDs!

---Joel

No, but it would probably work better as a pizza oven. ;-)

The motherboard in that widget you were playing with has something like 1700 components.

Five or six is OK, as long as you don't want to do RoHS. If you have any plans to do RoHS, the more the merrier. Five works, if nothing goes wrong but it stresses parts more than I'd like. With nine or eleven stages you can soak everything longer and then spike it for the reflow.

AIUI, we did contract manufacturing at first, too. It's a bigger PITA than it's worth. Splitting allegiances isn't a good position to be in, either.

We abused the software quite a bit. If you do everything by the book they may work. ;-)

I really liked Synplify (Amplify was a sweet idea too). Too bad Synopsis bought 'em. Actually, I'm finding that the freebie Altera stuff works pretty well. I haven't really stressed it, but it's very easy to use. I like the direction they're going, too.

...with ten years experience doing the never-been-done-before thing with hardware that's two years old.

Hi Keith,

We have some boxes that are something like 3,000 parts... but they're spread over a large handful of boards inside.

So you win for "most parts on a single board." :-)

I'd still be worried that massive ferrite choke on the internal Ethernet cable might get lose some day and start smashing up all those nice audio transformers and relays you have in there!

Hmm, good points. I'll keep that in mind.

Agreed; Synplify was quite good. I was no longer doing FPGA design by the time Synopsys bought'em, at least.

The Cypress VHDL synthesis tool (Warp) was nice in that (kinda similar to LTSpice) it'd been written largely by a single guy up at Cypress's Beaverton, Oregon office -- made for nice "one stop shopping" for tech support if you ever needed it.

---Joel

If I did it again I think I could cut it by almost half, or get rid of the other board completely. Not going to happen, though.

It's still on the rope. ;-) You should see the monster on one of the flat cables in our football product. It's a real Rube. Compliance afterthoughts are seldom pretty. :-(

It brings home some bacon, I understand. Ask your boss, "if it comes down to running our product or theirs..."

I played around with Actel's a bit too. It seems to work, but I don't like their parts as much. LUT-3s do an amazing job of eating up cells (multiply your estimates by at least two). OTOH, Xilinx's new LUT-6 (Spartan 6) is sweet. I'm 95% sure I'm going to stick with Altera, though. Cost and packaging are really what drives the decision.

figure

that was what we called our old ovens at Microdyne. "Call the M.E., the pizza oven is down again". They finally replaced the pair with a computer controlled Heller oven.

And 18 months on parts released, within this week?

In 1996, while interviewing for a job I was told that one of the requirements was 15 years experience with Win 95. I pointed out that they were fools, and walked out. They weren't around for long. I guess they couldn't find enough experienced people. :)

talking

figure

Actually, the oven is fine for what it is. The RoHS profile is just asking too much from it.

talking

figure

The ones at Microdyne were old when I started there, over 13 years ago. They needed two, just to keep one running. They were going to overhaul the better unit after they bought the Heller, and set it up for engineering to play with, so they didn't keep disrupting production. Suddenly engineering didn't waste so much time, playing with Production's toys. :)

Hey, that's almost possible. After all, it's just MS-DOS with a GUI glommed on the top.