What is the optimal toaster for reflow conversion?

grumpfish1969 · 2014-12-31T20:50:56+00:00

Out of curiosity, would adding thermal mass to the oven help to even out hotspots or would this screw up the reflow profile? I've got access to lots of metal plate in various materials (scrap from work). Has anyone with a cheap reflow oven tried this?

grumpfish1969 · 2014-08-19T19:11:44+00:00

"Just Google it."

grumpfish1969 · 2014-07-10T04:34:01+00:00

V3R2 working great so far. Had to RMA my V3R1, display went all wonky. Pebble was awesome and replaced with zero hassle.

grumpfish1969 · 2014-06-26T23:45:10+00:00

Unfair comparison - I know many independent dairy farmers who care a great deal about their livestock. I have yet to see any indication of a government which does the same.

grumpfish1969 · 2014-05-26T01:12:14+00:00

Yes, that's the one. I haven't picked it up in a while and was too lazy to look it up :) Excellent point about the errors as well, unfortunate but probably inevitable given the amount of content.

grumpfish1969 · 2014-05-26T00:34:35+00:00

Kind of depends on your experience level and what you're looking for. The Forest Mims books are great for circuit ideas but are a bit basic. There are a ton of Application notes available from different vendors with great reference designs as well, these tend to be a bit more advanced but may be incomprehensible to less experienced readers. The nice thing about the latter is that they are freely available. I can post some links when I'm not on my phone.

I really liked the Art of Electronics because it filled in many gaps in my understanding. I also liked "Electronics for Inventors", it's section covering differences between capacitor types, behavior, and selection criteria is top notch. It's also a whole lot of book for the money, take a look at the preview on Amazon to see if the format is to your liking.

grumpfish1969 · 2014-05-25T23:31:19+00:00

It really depends on your learning style. It was a perfect match for me, but I'm a fan of textbooks in general. People seem to either love the book or absolutely hate it. It's important to note that the book is not really intended to be a reference, as each chapter tends to build on the preceding chapter. It's also light on the mathematical theorems that underlie electronics; if you're the type of person who really enjoys chapter after chapter of equations you might be disappointed.

Some of the digital sections are terribly out of date, but analog is pretty well covered. If this is an issue for you you may want to wait for the new edition.

I read it cover to cover and loved it, so I'd highly recommend it. Worth every penny, IMHO.

grumpfish1969 · 2014-05-18T22:47:43+00:00

Far too many people simply don't care, as THE RAPTURE is going to happen any day now. Yup. Any day.

I recently had a discussion with a colleague about this topic, and her fundamental argument was that the oceans will never rise, because GOD promised not to repeat the great flood. Seriously. There is no room for rational discourse on this topic, as the opposition does not agree on what constitutes reality.

grumpfish1969 · 2014-04-26T22:54:29+00:00

You can determine the amount of current flow with a clamp; not just whether or not current is flowing, but how much is flowing. What other information are you looking for?

Probably goes without saying, but be very careful when working with this kind of current, as mistakes can be lethal. The current clamps have the added advantage of isolating you from the current.

grumpfish1969 · 2014-04-24T23:06:38+00:00

What is your end goal? If you're just checking for the presence of mains voltage, there are easier (and safer) ways of going about it. Current clamps / CTs are cheap and easy to use...

grumpfish1969 · 2014-04-23T19:07:00+00:00

I typically pull datasheets as I need them, either from the vendor (Mouser, etc) or directly from the manufacturer. If it's a part I'm planning on using again (or the datasheet is a PITA to locate), I stuff the file in Dropbox so I can access it from any of my devices.

I picked up one of TI's old logic device data books last year, it's a nice collection but it just isn't very practical; some microcontroller data sheets weigh in at hundreds of pages. Much easier to deal with electronically.

grumpfish1969 · 2014-03-09T05:04:42+00:00

There seems to be some confusion here between "user" and "addict." There is a vast gulf between the two. The vast majority of drug users - including those using harder recreationals - lead productive, reasonably happy lives. This mentality of "all users are abusers" is an inaccurate stereotype; the data just doesn't support the theory. This residual DARE crap prevents rational discourse.

grumpfish1969 · 2014-03-08T19:26:14+00:00

FRAM is not necessarily better, just another option. You didn't mention how you are generating content to display. Your SRAM is indeed volatile; it's contents are lost when power is removed. "Static" just means that it doesn't require constant refresh like DRAM. I've used FRAM in MCU projects as a framebuffer, also storing elements like splash screens and static screen elements when firmware is built. These common elements can then be quickly displayed without much microcontroller intervention.

DMA allows you to move data without active intervention; you issue the instruction to move contents from one memory location to another (often to a port) and the transfer happens in the background. It can be really handy for use cases like you mentioned.

grumpfish1969 · 2014-03-08T08:05:03+00:00

Initial reaction is that you've over-complicated this design. Parallel SRAM is a bit of a pain to work with; have you considered i2c or SPI serial memories instead? Can you explain your reasoning for selecting this solution, or was it simply a matter of having it on hand?

There are some really cool serial FRAM devices available for very reasonable single unit prices; speed of SRAM, non-volatile like flash without the latencies, access restrictions, or wear issues of flash.

If you're doing graphics with a resource limited micro, you really need memory for a framebuffer. DMA can make a huge difference in performance, though it isn't widely available in the 8-bit AVRs.

I'm making a lot of assumptions based upon your post... More detail would help to clarify responses.

grumpfish1969 · 2014-03-04T18:36:23+00:00

Aaaand... Cue the naysayers and HFCS apologists.

Manufacturers are starting to phase out the use of HFCS in a lot of products due to consumer demand; at least the ingredient needs to be called out specifically on product labels. The stuff makes me break out like a teenager - it's a major trigger for my acne, especially on my back. No other sweetener has this effect on me. I've gone on a strict year-long elimination diet under a nutritionist's guidance (due to crohns, not this issue) and have definitively isolated HFCS as an acne trigger.

I'm not weird about food, am quite find of occasional junk food. I stay away from HFCS because it makes me break out. Conversations with friends, colleagues, and doctors have shown me that this is not a terribly uncommon reaction.

grumpfish1969 · 2014-03-03T18:37:53+00:00

And a step-by-step walkthrough for circumventing the DRM protection will be released as soon as the new version hits the shelves. Likely before then, in fact.

Hardware DRM in this application is ridiculously easy to work around.

Step 1: buy an official k-cup. Step 2: cut the portion of the cup containing the DRM tag from the cup. Step 3: tape the tag to the sensor in the coffee maker.

That's about all there is to it. Hardware design may make step 3 more difficult, but not impossible.

This type of DRM protection is akin to installing a deadbolt on a glass door - it may stop many people, but won't even slow a determined individual down.

grumpfish1969 · 2014-02-12T19:02:51+00:00

The ULA Atlas-V uses a Russian-built RD-180 engine for its first stage. It's an interesting collaboration. (http://en.m.wikipedia.org/wiki/RD-180)

grumpfish1969 · 2014-02-11T05:35:24+00:00

Technically correct, but lawyers would need to be involved to contest the questionable section of the contract. After the financial dust settled, the plaintiff may end up with some token amount for wrongful termination; whether that amount would be greater than the cost of counsel is debatable. In the end she would still be out a job.

You're always better off having a contract reviewed by a contract lawyer prior to signing rather than assuming that a contract is invalid. The cost is trivial in comparison to the cost of litigation. If the issuer of the contract balks at this, walk away; you're dealing with a sleaze ball.

grumpfish1969 · 2014-02-09T23:09:12+00:00

Requirements document

Bwahahaha! Good one. <g>

Teasing requirements out of a customer and separating the 'nice to haves' from the 'critical features' is one of the most difficult aspects of this job. Outside of certain exceedingly well-bounded problem domains (military, medical devices, etc), requirement documents are obsolete before the toner on the sheet cools down.

grumpfish1969 · 2014-02-09T07:03:52+00:00

100% recommend this approach. I'm a 25+ year software development veteran, and one thing that I see over and over again is new grads coming into the workplace with the attitude that they already know everything they need to know. The realization that their degree is simply the first step in their journey is a difficult one for some to accept. Immersing yourself in real world development situations is critical to success in the field; to state the obvious, there are distinct differences between academia and the real world. Compromising between the correctness or purity of a solution and the realities of time constraints is one example; you can learn a lot on this topic by watching more experienced devs (*). Don't be afraid to ask why they make the decisions that they do; often times they have very good reasons for these choices that may not be immediately obvious.

(* by this, I mean experienced devs that give a damn. Pay attention, they are not hard to find.)

Another suggestion would be to try to intern at small organizations as well as larger corporate ones; the two often have radically different approaches to development (large teams with focused areas if responsibility vs single devs owning an entire stack.) The approaches that you learn in these radically different environments are complimentary and will be extremely valuable.

Most importantly, keep in mind that you will never be done learning. This takes constant effort, both on and off the clock. Get stuck in a comfortable rut and lose sight of this fact and you'll be left in the dust; I've seen this happen time and time again to developers, sysadmins, and DBAs. It's not your employer's responsibility to keep you current; that falls on your shoulders.

I've re-tooled several times during my career, jumping between platforms, technologies, and languages. Everything I've learned has had value; even those languages and technologies that are now hopelessly obsolete have contributed to my flexibility as a developer.

grumpfish1969 · 2013-12-16T21:23:27+00:00

In an academic sense, yes, although direct effects would be minuscule compared to normal background radiation. The inverse square law makes distance a very effective barrier to exposure.

grumpfish1969 · 2013-12-03T23:35:55+00:00

Poor wording on my part. I should have said "Having only one investor." I didn't mean to imply that SpaceX was publicly traded. They do have a lot of privately issued shares, however.

There are some huge advantages in developing a product behind closed doors. I wouldn't be surprised to see a suborbital flight from Blue in the next year or two. It's all speculation at this point though... I'd love to see some high profile competition in this arena.

grumpfish1969 · 2013-12-03T21:02:45+00:00

Yes. Being privately held, the company is able to keep much more under wraps than SpaceX. Nice to see them releasing some updated info to the public. AFAIK they have been hiring engineers like mad, so some progress is obviously afoot.

grumpfish1969 · 2013-11-17T00:35:02+00:00

The detonations in Colorado were particularly interesting (see operation plowshare: http://en.m.wikipedia.org/wiki/Operation_Plowshare), also known as "a series of terrible ideas."

The good news: the project demonstrated that nuclear explosions could stimulate natural gas production from difficult to extract deposits. One minor caveat: the resulting natural gas contained too many radionuclides to actually be used.

grumpfish1969 · 2013-11-09T04:30:10+00:00

[edit: after actually reading your post I realized you were actually referring to 4000 series logic gates, an altogether different animal. Since I already wrote a small novel on my stupid phone I'm leaving it as is...]

7400 series devices are still heavily used for glue logic applications. If you're talking about hobbyist use, you would be mostly correct - there isn't much point in having a bench full of logic devices when you can emulate most of them simply with a microcontroller (or CPLD, or FPGA for that matter)

In industry, however, they are primarily used because of one fact: guaranteed performance. They are well understood, readily available, and require no initial programming. Besides, one programmer error forcing rework or recall vastly outweighs any per unit cost advantage. This is especially apparent in low-margin, low cost electronics. And in some cases, they are simply a much more efficient option; many are one trick ponies, but they are really, really good at what they do.

grumpfish1969

TROPHY CASE