One SMT Breakout to Rule Them All

You need to use surface-mount technology (SMT) parts in your design. But you also need to prototype. How to fit those little buggers into your breadboard?

[Simon] came up with a general-purpose SMT-to-breadboard solution. Now, there are already myriad adapter boards for the many-pin devices: SSOP-to-DIP adapters and so on. But what do you do when you just need to work that tiny SOT223 voltage regulator into a breadboarded circuit?

[Simon]’s solution fills that gap with one breadboardable design to handle all of your small-pin-count part needs. It accommodates SOT223, SOT323, and SOT23 three-pin parts like transistors or voltage regulators, and also has pads for all of the common two-terminal parts like resistors and capacitors from 0402 on up to 1206. You could build up a full voltage regulator circuit on one of these things. He’s even included some whitespace on the back for your notes.

SMT parts aren’t even the future any more. And with the right procedure, they’re not hard to hand-assemble. So the next time you have some extra space in a PCB order, toss in a couple of [Simon]’s breakouts and you’ll be ready for your next breadboarding session.

Measuring Parts for Accurate Reverse Engineering

Previous headquarters of Useful Thing Inc.
Previous headquarters of Useful Thing Inc. They made the best widget you could buy in the 80s.

Like most hackers, I’ve run into a part that looks like it might do what I want, but the only documentation came from a company so thoroughly defunct their corporate office is now a nail salon and a Subway.

So, as any hacker who’s wandered through a discount store with a spare twenty, at one point I bought a Chinese caliper. Sure it measures wrong when the battery is low, the temperature has changed, if I’ve held it in my hand too long, the moon is out, etc. but it was only twenty dollars. Either way, how do I get accurate measurements out of it? Well, half-wizardry and telling yourself educated lies.

There are two golden rules to getting accurate measurements by telling lies. It may be obvious to some, but it took me quite a bit of suffering to arrive at them.

  1. Engineers are lazy. So lazy. Most things are going to be even numbers, common fractions, and if possible standard sizes. If sheets and screws come in 2 and 3mm then you bet you’re going to see a lot of 2mm and 3mm features. Also, even though the metric world is supposedly pure, you’re still going to see more 0.25 (1/4) mm measurements than you are .333333 (1/3) mm measurements. Because some small fractions are easier to think about than decimals.
  2. Your eyes lie. If it matters, measure it to be sure.

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Poor Man’s Time Domain Reflectometer

A time domain reflectometer, or TDR, is an essential piece of test gear when working on long cables. The idea is simple: send a pulse down the cable and listen for the reflection from the far end. The catch is that pesky universal constant, the speed of light.

The reason the speed of light is an issue is that, in a traditional system, the pulse needs to be complete before the reflection. Also, time is resolution, so a 1 GHz sampling rate provides a resolution of about 10 centimeters. [Krampmeier] has a different design. He sends variable length pulses and measures the overlap between the outgoing and reflected pulses. The approach allows a much simpler design compared to the traditional method.

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iPhone Microscopy and Other Adventures

CMOS imaging chips have been steadily improving, their cost and performance being driven by the highly competitive smartphone industry. As CMOS sensors get better and cheaper, they get more interesting for hacker lab projects. In this post I’m going to demonstrate a few applications of the high-resolution sensor that you’ve already got in your pocket — or wherever you store your cell phone.

CMOS vs CCD

First lets quickly review image sensors. You’ve probably head of CMOS and CCD sensors, but what’s the difference exactly?

cddandcmos
CCD and CMOS imaging sensors: from this excellent page at CERN.

As the figure above shows, CCD and CMOS sensors are both basically photodiode arrays. Photons that hit regions on the chip are converted into a charge by a photodiode. The difference is in how this charge in shoved around. CCD sensors are analogue devices, the charge is shifted through the chip and out to a single amplifier. CMOS sensors have amplifiers embedded in each cell and also generally include on-chip analogue to digital conversion allowing complete “camera-on-a-chip” solutions.

Because CMOS sensors amplify and move the signal into the digital domain sooner, they can use cheaper manufacturing processes allowing lower-cost imaging chips to be developed. Traditionally they’ve also had a number of disadvantages however, because more circuitry is included in each cell, less space is left to collect light. And because multiple amplifiers are used, it’s harder to get consistent images due to slight fabrication differences between the amplifiers in each cell. Until recently CMOS sensors were considered a low-end option. While CCD sensors (and usually large cooled CCD sensors) are still often preferred for scientific applications with big budgets, CMOS sensors have now however gained in-roads in high performance DSLRs.

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Everyman’s Turbomolecular Pump

What can you do with a very good vacuum pump? You can build an electron microscope, x-ray tubes, particle accelerators, thin films, and it can keep your coffee warm. Of course getting your hands on a good vacuum pump involves expert-level scrounging or a lot of money, leading [DeepSOIC] and [Keegan] to a great entry for this year’s Hackaday Prize. It’s the Everyman’s Turbomolecular Pump, a pump based on one of [Nikola Tesla]’s patents. It sucks, and that’s a good thing.

The usual way of sucking the atmosphere out of electron microscopes and vacuum tubes begins with a piston or diaphragm pump. This gets most of the atmosphere out, but there’s still a little bit left. To get the pressure down even lower, an oil diffusion pump (messy, but somewhat cheap) or a turbomolecular pump (clean, awesome, and expensive) is used to suck the last few molecules of atmosphere out.

The turbomolecular pump [DeepSOIC] and [Keegan] are building use multiple spinning discs just like [Tesla]’s 1909 patent. The problem, it seems, is finding a material that can be made into a disc and can survive tens of thousand of rotations per minute. It’s a very, very difficult build, and a mistake in fabricating any of the parts will result in a spectacular rapid disassembly of this turbomolecular pump. The reward, though, would be great. A cheap turbomolecular pump would be a very useful device in any hackerspace, fab lab, or workshop garage.

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Retrotechtacular: Rein-Operated Tractors

It’s not unusual for new technologies to preserve vestiges of those that preceded them. If an industry has an inertia of doing things in a particular way then it makes commercial sense for any upstarts to build upon those established practices rather than fail to be adopted. Thus for example some industrial PLCs with very modern internals can present interfaces that hark back to their relay-based ancestors, or deep within your mobile phone there may still be AT commands being issued that would be familiar from an early 1980s modem.

Just occasionally though an attempt to marry a new technology to an old one becomes an instant anachronism, something that probably made sense at the time but through the lens of history seems just a bit crazy. And so we come to the subject of this piece, the rein-operated agricultural tractor.

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3D Printed Linkage Produces Automatic Hacksaw!

The more tools you have the better. Unfortunately, not everyone has the space, or the money for full-size equipment. Looking to expand his maker capabilities, [Bruno] had the clever idea to turn a hand-tool, into a power tool. One we’ve never even seen before — a powered hacksaw.

Using his 3D printer he designed a linkage system, not unlike a steam locomotive drive to turn rotary motion from a geared motor into linear motion. Not only that, it also angles the hacksaw as it goes. 3D printed brackets hold the hacksaw in place, and weight can be added to the top to adjust the cutting speed. He even 3D printed a guide for his vice to line up the material to where the blade will cut.

It’s a bit slow, but it’s fantastic at making cuts! Continue reading “3D Printed Linkage Produces Automatic Hacksaw!”