Reverse Engineering Salvaged Part Footprints

February 1, 2013 by Mike Szczys 35 Comments

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So you just pulled a fancy component off of a board from some broken electronics and you want to use it in your own project. What if the data sheet you found for it doesn’t include measurements for the footprint? Sure, you could pull out your digital calipers, but look at the measurements in the image above. How the heck are you supposed to accurately measure that? [Steve] found an easy answer for this problem. He uses microscope software to process an image of the board.

One common task when working with a microscope is measuring the items which are being viewed under magnification. [Steve] harnessed the power of a piece of free software called MiCam. One of its features is the ability to select an area of the photograph so serve as the measuring stick. To get the labels seen in the image above he selected the left and right edges of the board as the legend. He used his digital calipers to get a precise measurement of this area, then let the software automatically calculate the rest of the distances which he selected with his cursor.

MiCam is written for Windows machines. If you know of Linux or OSX alternatives please let us know in the comments.

Turning The Stellaris Launchpad Into A Logic Analyzer

January 27, 2013 by Brian Benchoff 20 Comments

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If you have a Stellaris Launchpad sitting around, have a go at using it as a logic analyzer

The Stellaris logic analyzer is based upon this earlier build that took code from a SUMP comparable Arduino logic analyzer and ported it to the much faster and more capable Stellaris Launchpad with an ARM Cortex 4F processor.

This build turns the Launchpad into a 10 MHz, 8-channel logic analyzer with a 16 kB buffer comparable with just about every piece of software thanks to the SUMP protocol. Even though the ARM chip in the Launchpad isn’t 5 Volt tolerant, only pins 0 and 1 on Port B are limited to 3.6 Volts. All the other pins on Port B are 5 Volt tolerant.

Not a bad piece of work to turn a Launchpad that has been sitting on your workbench into a useful tool.

$20 Vacuum Pen Build On Of The Best We’ve Seen

January 25, 2013 by Mike Szczys 9 Comments

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Everything you need to build a vacuum tweezers is laid out in this image. The parts should run you about $20 and when you’re done you’ll have the perfect tool for placing very small surface mount parts for reflow soldering.

This project uses the same concept as other fish pump tweezers projects but builds upon them with some interesting additions. The first step in the conversion process is to tear down the aquarium pump to reverse its flow. There are several steps but all-in-all it’s not very difficult. With the source of vacuum established [Technically Artistic] begins work on the business end of the tool. This is where the array of different pens see some action. The large blue one is the outer assembly, with the others combining to help connect it to the plastic tubing. The business end is made from a needle adapter for an air compressor, with an alligator clip cleverly modified to serve as a valve to release the parts from the tip.

Fitting A Cold, Metal Heart In An Altoids Tin

January 24, 2013 by Brian Benchoff 18 Comments

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[James] has been building a heart rate monitor using a very cool TI chip. He needed a way to test his device, and commercial ECG simulators, like all biotech devices, are absurdly expensive. [James] decided to build his own heart rate simulator, and in the process made a great tool and one of the most well documented projects we’ve ever seen.

Of course, if you’re building an ECG simulator, you’re going to need a good sample of a heart’s electrical pattern. To get this sample, [James] found an old army manual with a diagram of an ideal ECG pattern. [James] took this PDF manual, screen capped the diagram, and used a Python script to generate an array in C the Arduino could repeat over and over.

The rest of the build consisted of a D/A converter, a pot to change the heart rate, a very nice seven-segment display, and a few banana jacks to connect to [James]’ heart monitor. Everything is up in a git, including an amazingly well documented (87 pages!) tutorial for building your own Arduino heart simulator.

Laser Cut PCBs

January 22, 2013 by Brian Benchoff 45 Comments

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Despite what you may have heard, those 40 Watt laser cutters actually can cut out traces on your next PCB.

Since he got his laser cutter a year and a half ago, [Rich] over at Nothing Labs has been trying to cut PCBs with it. Others have tried, usually by masking off a piece of copper followed by chemical etching. [Rich] wanted a one-step process, though, and his laser cutter really isn’t up to the task of cutting metal.

All that changed when he heard of another maker cutting .001″ thick stainless steel on a similar laser cutter. Stainless steel isn’t solderable, but mild steel is. After finding a very thin piece of mild steel, [Rich] taped it down to a sheet of acrylic, designed a simple 555 blinky LED circuit, and tried out a new technique.

It turns out it is possible to cut very thin steel into circuit traces, and with enough flux to turn them into a functional circuit. As a bonus the resulting circuit looks really cool and a board can be made in mere minutes.

It’s not the thing for very fine work – the minimum trace width [Rich] can get is about 1/16″, but it is a very fast way to prototype a few circuits.

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Award Clock Put To Good Use As A Bench Meter

January 21, 2013 by Mike Szczys 6 Comments

The motivation industry turns out these type of award trinkets by the millions. Here’s a way to actually put the thing to use. Instead of displaying time, the clock dial serves as the readout of a voltage meter.

When we first saw this post we assumed that the hack used some type of coil injection to drive the hands. But it turns out that this is mechanically driven. The image above shows the stepper motor which is mounted behind the clock. Its drive shaft is coupled with the adjustment knob on the back of the clock. The precision of the motor lets the PICAXE set the clock dial based on the number of motor steps. The hour hand shows the tens value with the minutes serving as ones (base 10, not base 60). This means the top measurable voltage is 12V — when the hour hand is at 12 the measurement is 0 volts plus tenths of a volt from the minute hand. With the dial taken care of the rest of the project focuses on measuring the voltage using the ADC, which has an upper limit of just 5V. This is overcome with a simple voltage divider.

After the break you can see the accuracy of the rig as it performs measurements next to a digital voltmeter.

Continue reading “Award Clock Put To Good Use As A Bench Meter” →

Building A Tool To Bend Small Metal Tubes

January 21, 2013 by Brian Benchoff 32 Comments

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[Joel] is setting up a really nice workshop. Included in his list of machinery are the staples of any workshop; a lathe, miter saw, containers full of organized screws, and a manual mill converted to a CNC machine. [Joel] wanted an oiling system for his mill, and like any good maker decided to fabricate his own. This required bending very small diameter brass tubes, something doable by hand (or without sand, at least). He decided to solve this problem with a DIY tube bending tool that allows him to bend tiny brass tubing without the walls collapsing.

[Joel] broke out his lathe and machined two brass rollers with a groove to hold his 3/16″ tubing. One of these brass rollers is attached to a handle, while the other is attached to a block that gets clamped into [Joel]’s bench vise. After threading some tubing through the rollers, [Joel] is able to bend it precisely with only a tiny bit of collapsing on small-radius bends.