tag:blogger.com,1999:blog-161435492024-03-07T07:57:01.616-08:00A Cleverly Titled Electronics BlogA blog devoted to amateur electronics with information on projects that I have done, other sites with good circuits, sources for purchasing parts, and more for the hobbyist.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.comBlogger43125tag:blogger.com,1999:blog-16143549.post-45726014833660945452014-03-23T18:29:00.001-07:002014-03-23T18:35:31.266-07:00Printrbot Simple Build Volume UpgradesI received a <a href="http://printrbot.com/support/printrbot-simple/">Printrbot Simple</a> (late 2013 version) as a (wonderful!) Christmas gift this year. Everything assembled nicely and the prints have been great so far. One thing that's bugged me since day one, however, is the very small build area (roughly 4" cubed). I set out to change that and have decided to detail my process so far and post updates as I continue.<br />
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First Upgrade</h2>
The first upgrade I did was to print out <a href="http://www.thingiverse.com/">Thingiverse</a> part number <a href="http://www.thingiverse.com/thing:215294">215294</a> to increase the build volume from 100mm on the X-axis to 160mm. This was a huge step forward as it greatly increased the number of useful object I could print. It was a relatively simple print (everything was oriented to print on the stock bed) and only required a few parts to be purchased. These parts were:<br />
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<li>8mm smooth rod (McMaster-Carr part# <a href="http://www.mcmaster.com/#88625k67/=q6b90w_">88625K67</a> or on <a href="http://www.amazon.com/gp/product/B0050RMXJO/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1">Amazon</a>)</li>
<li>608 skate bearings (McMaster-Carr part# <a href="http://www.mcmaster.com/#5972k222/=q6bd0e">5972K222</a> or on <a href="http://www.amazon.com/gp/product/B002BBICBK/ref=oh_details_o00_s02_i01?ie=UTF8&psc=1">Amazon</a>)</li>
<li>Printrbot GT2 Kit (From <a href="http://printrbot.com/shop/gt2-kit/">Printrbot</a>)</li>
<li>Miscellaneous M3 screws (Hardware store, McMaster-Carr, Amazon, etc.)</li>
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I followed the <a href="http://www.thingiverse.com/thing:215294/#instructions">instructions</a> from the Thingiverse listing and everything went quite well. I cut the 36" rod that I bought in half and only used a small portion of these with the original bed. I used this setup for a couple of weeks before starting to get the itch to grow the printer further. </div>
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A few notes of caution: this build isn't for the feint of heart - it involves dismantling most of the bottom of the printer since the motor plate has to be replaced with a printed piece. Also, don't make the mistake I did and let the nut fall out for the top screw on the left side. It took me quite some time to wiggle that guy back into the right place using a magnetized screwdriver, a steady hand and many attempts. Also, make sure you clean the extra plastic off of the protuberance that hits the X-axis limit switch. I didn't do this at first and was greeted with a very sickening (although not damaging) noise as some of the layers separated.</div>
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Second Upgrade</h2>
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The second upgrade I did was Thingiverse part number <a href="http://www.thingiverse.com/thing:257841">257841</a> which is a beefier version of the first, but without the adjustable piece that would allow usage of the original bed. If I were to start over from the beginning, i would print just that piece from the previous build and the rest of this build. That would allow the better end-pieces with the adjustable nature of the original. Live and learn! Since I didn't do the adjustable piece and I had planned from the beginning to make a super-big bed, I replaced the stock bed with a piece of Lexan that I cut with a jigsaw and drilled for the screws. I would definitely thing about having this laser cut if that's an option and am considering getting a second piece and having that done. The result would be a lot cleaner and more precise, but this is working for now on the cheap. I've been printing directly on the Lexan, which produces nice shiny first layers and the adhesion has been quite good.</div>
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I changed the way the timing belt is attached by using one tension block on each end instead of just on one. I also used Thingiverse part number <a href="http://www.thingiverse.com/thing:275874">275874</a> to wedge into the opening on the tension blocks so that I could use the timing belt without cutting the belt. This has worked great for giving extra control over the tension and to prevent having to modify the belt in case I ever decide to go "just a little bit bigger"<br />
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The keen-eyed reader will notice that the bed is quite a bigger along the Y-axis than it would need to be for the standard Y carriage and the keen reader would be right! This is all the farther I've gotten so far, but there will be more to come (one piece of the next upgrade is on the printer as I type this).</div>
Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-73330474490405799622012-10-29T19:19:00.000-07:002012-10-29T20:14:56.766-07:00Robot Halloween CostumeI decided it might be time to revive my old electronics blog.<br />
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My wife and I built this robot costume for our four year old son this year.<br />
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The main part is made from a diaper box spray-painted silver with a detachable front 'control panel'. The hat is made from a wipes box with a plastic fire hat modified to allow visibility out of the hand hole in the box. With 18mo old twins, we have lots of nice cardboard boxes from baby products around our house that make fantastic building and storage products. Leftover foil tape from some duct work helps complete the look and holds everything together.<br />
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All of the electronics are driven by an Arduino Diecemila. I salvaged a slick little VFD from some scrap equipment - it's a Noritake GU112X16G-7000 (<a href="http://www.noritake-elec.com/7000.htm">details</a>) and is driven via the serial interface at 38400 baud. Since the Arduino serial levels are inverted from RS232, I had to build an inverting board based on a <a href="http://embeddederic.blogspot.com/2011/08/little-old-school-displaying-going-on.html">design</a> I found online. The LEDs at the bottom are 10mm RGB and are driven by a pair of daisy-chained 74HC595 shift registers to save i/o pins on the Arduino. This makes it very easy to add lots of LEDs to a project without a lot of hassle and are quite expandable without a lot of effort. Normally the LEDs cycle through a shifting spectrum with a narrow 'window' to show a nice range of colors at all times. The buttons are arcade style buttons sourced from <a href="http://www.sparkfun.com/">Sparkfun</a>; they temporarily switch all the LEDs to whatever color is pressed, singularly or mixed to match whatever buttons are pressed (red, green, blue, yellow, cyan, magenta, or white). A small piezo speaker beeps out random 'robot noises' to add another dimension to the costume. I have an ultra bright 10mm red LED in the ball on top (hollowed out Styrofoam) that blinks out 'HALLOWEEN' in morse code. I outlined the front in green EL wire with a commercial EL driver that lets it stay solid, blink slowly or blink quickly; quickly looks the best in my opinion.<br />
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On the software side of things, the 'loop' portion of the Arduino code checks the current millis() and performs a modulo to see if it's time to run the various portions of the code (changing the image on the display, checking the buttons, cycling the colors on the LEDs, blinking the red LED, and pushing sound to the speaker). This allows for all of the components to update without blocking so everything runs smoothly. I'm sure there's a better way to accomplish this, but for a quick (ha!) Halloween hack, this seems to be working pretty well. Once I get the code cleaned up a little bit, I'll post it and link it here.<br />
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Videos:</h3>
(I apologize for the vertical orientation - it worked well for the vertical orientation of the costume and I originally shot them to share on my phone)<br />
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Early test - no sound - closeups on the VFD to show the images.<iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.youtube.com/embed/JDKRoqY541M?feature=player_embedded' frameborder='0'></iframe></div>
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Further along - this time with the sound effects working (still no paint).</div>
<iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.youtube.com/embed/Gl5nQzhv6ZU?feature=player_embedded' frameborder='0'></iframe>Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com1tag:blogger.com,1999:blog-16143549.post-1142536492525523232006-03-16T11:14:00.000-08:002012-10-29T19:57:27.050-07:00Alphanumeric LED Display<div style="float: right; margin-bottom: 10px; margin-left: 10px;">
<a href="http://www.flickr.com/photos/danwake/109245983/" title="photo sharing"><img alt="" src="http://static.flickr.com/40/109245983_89567b2d13_m.jpg" style="border: solid 2px #000000;" /></a> <br />
<span style="font-size: 0.9em; margin-top: 0px;"> <a href="http://www.flickr.com/photos/danwake/109245983/">Alphanumeric LED Display</a> <br /> Originally uploaded by <a href="http://www.flickr.com/people/danwake/">DanWake</a>. </span></div>
HPDL-1414 Alphanumeric Display<br />
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I recently acquired a little gem from an old piece of equipment we were throwing away at work - that gem is the HPDL-1414 four character alphanumeric display. It is a small chip manufactured by Hewlett Packard that contains four tiny, red LED alphanumeric displays behind glass magnifying lenses. The chip itself is CMOS, however it runs at TTL voltages, making it easy to interface with. Interfacing is very simple from a logic level as well - simply set the write enable pin high (disable writing), set the 2 bit character address via the address lines, set the 7 bit ASCII value of the character via the data lines, pull the write pin low (enable write), rinse, lather, and repeat for each character. The only disadvantages that I have seen with this display are that it does not support full ASCII (capital letters and some symbols only), the characters are not very bright (although this could be because I'm not giving enough voltage to VDD (I'm currently running it off of the 5v from the parallel port to save wires), and the letters themselves are fairly tiny. Otherwise, this is a great little display that is very easy to work with and tons of fun to write software for. <br />
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Currently I have a few functions written in C to put characters at individual addresses, scroll a text string at arbitrary speed (from super, mind-numbingly fast, to as slow as you want), and just for fun a function that switches all of the segments from '1' to '/' to '-' to '\' fairly fast, producing a rather interesting and attention-grabbing spinner effect.<br />
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The physical aspects of the construction were fairly straight-forward: I hacked up an old parallel printer cable for the computer connection by using trial and error with a multimeter to find which wire goes to which pin; the case is, fairly obviously, an old Altoids tin which I Dremelled out to make a window and lined with electrical tape. I initially tried to make my parallel cable using a 25-pin header that I tried soldering phone cable to. I would not advise trying this, as phone cable insulation tends to melt at fairly low temperature making it very not-fun to solder. And - after I eventually did get all the little wires soldered at each end, one of my lines was goofed up preventing all of the characters from appearing, and generally frustrating me to the point where hacking up an old printer cable was rather cathartic. Just a word of warning.<br />
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So - if you can get your hands on one of these, by all means go for it - I'm sure that it would be very useful in any project for which you can spare a few data lines and want to add a really neat retro looking display to get some data to the user.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.comtag:blogger.com,1999:blog-16143549.post-1133878126451625752005-12-06T05:42:00.000-08:002005-12-06T06:14:13.676-08:00Fun Little Project: Minty Mouse<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://photos1.blogger.com/blogger/6891/1521/1600/Minty%20Mouse0001.jpg"><img style="float:right; margin:0 0 10px 10px;cursor:pointer; cursor:hand;" src="http://photos1.blogger.com/blogger/6891/1521/320/Minty%20Mouse0001.jpg" border="0" alt="" /></a><br />First off - I'll admit - <a href="http://www.makezine.com/blog/archive/2005/03/the_minty_mouse.html">others</a> have used the same name for their projects like this. And no, this really isn't directly related to electronics. But, it is related to fabrication which is usually the last, and most overlooked, step when doing a project. You've got a wonderful little circuit that amplified headphones, charges your iPod, and squeezes fresh orange juice, but how do you package it? Radio Shack sells some nice <a href="http://www.radioshack.com/family/index.jsp?categoryId=2032276">project enclosures</a> at fairly reasonable prices ($2.29 - $6.99 right now) that give a nice finished look to a project. <br /><br />You can also use items that aren't necessarily designed for the hobbyist, but which work very well. As in this project, the Altoids and Altoids-like tins are fairly popular for their small size, durability, and cheapness; you also get mints as a bonus! <a href="http://www.glad.com/containers.html">Gladware</a>, <a href="http://www.ziploc.com/food-storage-containers/">Ziploc</a>, and other similar containers are relatively cheap and can provide an assortment of sizes for various projects. They can also be made water-tight fairly easily and are made from thin plastic which is fairly easy to work with. For my <a href="http://danwake.blogspot.com/2005/11/computerized-christmas-lights.html">Christmas light project</a> this year, I'm building everything into a cheap <a href="http://www.lowes.com/lowes/lkn?action=productDetail&productId=82664-82673-19151&lpage=none">Stanley tool box</a> that I picked up for around $10 at <a href="http://www.lowes.com/">Lowes</a>.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://photos1.blogger.com/blogger/6891/1521/1600/Minty%20Mouse0002.jpg"><img style="float:left; margin:0 10px 10px 0;cursor:pointer; cursor:hand;" src="http://photos1.blogger.com/blogger/6891/1521/320/Minty%20Mouse0002.jpg" border="0" alt="" /></a><br />With all of that out of the way, here are the details on the construction of my version of the Minty Mouse. I started with a pseudo-Altoids tin and an old mouse that I found at work. I opened the mouse, discarded the top piece, removed the circuit board, and cut the sides off of the bottom piece to make it slightly smaller than the circuit board. I then sanded what I thought would be the thickness of the tin from the bottom of the bottom piece (later, it would turn out to be too much...) I then drilled a hole through the tin at the location where the mouse ball would need to protrude and smoothed the edges with sandpaper. The circuit board just fit inside the case without wiggle room, but the enclosure for the ball was a touch too tall - sandpaper took care of this and still left everything workable. The buttons were probably the trickiest part of the entire project - both in adding them to the top of the tin and in getting them to interface properly with the switches on the board. I cut three notches in the top of the tin using a <a href="http://www.dremel.com/HTML/home_fr.html">Dremel</a> (a tool which I would highly recommend!) with a grinding wheel. I also had to cut a notch out of the top edge of the bottom of the tin so that the buttons would have a place to move downward when they are pressed. Once I had finagled the buttons so that they operated clenaly, I used the trial and error method of determining how far above the switches the bottoms of the buttons were and bent two 'U'-shaped pieces of aluminum which I super-glued to the buttons.<br /><br />[edit] I forgot to mention what I did to fix the fact that I had sanded too much off of the bottom of the mouse. This fix was accomplished by cover the bottom of the tin with a packing label (also procured from work...) and building up a bar at each end of the bottom with thin strips of labels. The other advantage provided by this is that it makes the bottom look uniform (and covers up the lousy hole that I cut in the tin...) and helps to elevate the ball so that it rolls better. [/edit]<br /><br />All in all, this was not a terribly difficult project, just time-consuming, but I think the results are neat, and it's always interesting to see the looks on people's faces when the see you mousing with a small tin - especially if you open it up and offer them a stashed mint!Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1132676137134117542005-11-22T07:57:00.000-08:002005-11-29T07:25:49.443-08:00Computer SetupWhen building electronic projects, it's sometimes nice to have a PC around - for looking up datasheets online, pulling up schematics, or even for providing I/O while testing a circuit. My recommendation for a machine would be to use an older computer with a Pentium II 233 or so processor and as much RAM as you can cram into it. The older machine is nice in that it is fast enough for most simple things that it will be used for on a bench, but old enough that it can support all sorts of old cards and should have most of the "legacy" ports built into it.<br /><br />These "legacy" (I hate that word - these are such good ports, they're just old - call them classics or something) ports are the standard parallel, serial, and MIDI. The <a href="http://www.doc.ic.ac.uk/~ih/doc/par/">parallel port</a>, which long-time readers of this blog should know is my favorite, provides 12 digital output lines and 5 digital input lines. The <a href="http://www.aggsoft.com/rs232-pinout-cable/pinout-and-signal.htm">serial port</a> is another handy one which provides a TX (transmit) and RX (receive) line which can be used for programming, data-acquisition, and other similar uses. The unsung hero in my opinion of these classics is the <a href="http://www.technick.net/public/code/cp_dpage.php?aiocp_dp=pinconjoy_pc_game_midi">MIDI port</a> which provides 4 analog inputs which are each converted to an 8-bit value and 4 digital inputs.<br /><br />In addition to ensuring that these ports are present, the machine should have a network interface card (NIC) if you are planning to get online, or at the least a modem and a phone line. It might also be wise to look for some of the older ISA cards that are available that provide extra ports and connectivity - check eBay, local auctions, or old computers that people might be willing to part with for these.<br /><br />For software, I would suggest running either Linux or a version of Windows prior to Windows 2000 - Windows 98se is a good choice as it is the latest version before 2000 that isn't ME (I would advise no one to run ME...). The old versions are suggested because the versions of Windows that are NT based have security to prevent low-level access to the hardware ports. Also - it's nice to run real DOS sometimes for older applications and command-line based programs that you might write. Linux is also a very nice choice since it is so open, easy to program for, and lots of people who do hardware work run it.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1132674764243323542005-11-22T07:38:00.000-08:002005-11-22T07:52:44.256-08:00Programmable Integrated CircuitsA highly useful component for all sorts of projects is the <a href="http://www.microchip.com/">Microchip</a> brand <a href="http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=74">PIC</a> (programmable integrated circuit). The chips contain a microcontroller, some RAM, and some storage space (quantities and speeds depend on the particular model). Basically - one chip can act as a tiny stand-alone computer with inputs and outputs for controlling other circuits. Most are programmable in-circuit allowing for updates to the code that is run. To program one, you will need to <a href="http://www.google.com/search?num=100&hl=en&lr=lang_en&safe=off&c2coff=1&q=pic+programmer+schematic&btnG=Search">build</a> or <a href="http://froogle.google.com/froogle?q=pic+programmer&btnG=Search+Froogle&lmode=unknown">buy</a> some sort of PIC programmer (specifics again vary by model of chip to be programmed). You will also need some software for compiling code (unless you want to write assembly - your choice!) and sending it to the PIC. Microchip itself provides a free integrated devolpment kit (IDE) called <a href="http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en019469&part=SW007002">MPLAB</a> that works very well.<br /><br />If you are having troubles coming up with uses for this highly versatile devices, there are <a href="http://www.electronic-engineering.ch/microchip/projects/projects.html">many</a> <a href="http://www.olimex.com/dev/picprojects.html">ideas</a> and <a href="http://www.oshonsoft.com/picprojects.html">projects</a> <a href="http://www.epanorama.net/links/microprocessor.html#picproject">out</a> <a href="http://www.mcrosolv.demon.co.uk/pic.html">there</a>. Good luck!Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1132238607088000492005-11-17T06:18:00.000-08:002005-11-17T06:43:27.100-08:00Etching a Circuit BoardYou've got a circuit that you've prototyped on a breadboard, built using perfboard, and now you want something a little more professional to sell/give away/use/whatever. Or maybe you don't. Either way - you might want to take the next step with a good circuit and etch your own circuit board. This makes construction easier, the circuit potentially more compact, and it looks a lot nicer to boot. There are a few different ways to go about making the board - the most common is to apply some sort of a mask to a copper-clad board and then soak the board in a solution that dissolves the non-masked copper. Laying out the mask can be done by hand with a resist-ink pen (RadioShack sells a decent <a href="http://www.radioshack.com/product/index.jsp?productId=2102870&cp=&kw=etching&parentPage=search">kit</a> for doing this), <a href="http://www.fullnet.com/u/tomg/gooteepc.htm">ironing on</a> a printout from a laser printer, or by using a special <a href="http://www.technologystudent.com/pcb/PCB3A.htm">photo-resist board</a>.<br /><br />Another method which is somewhat popular (but much more difficult) is to make (or buy) a <a href="http://www.pathcom.com/~vhchan/cnc/cnc.html">computer numerically controlled (CNC) mill</a>. This is basically a drill press that has some method of either moving in two dimensions or moving the board in two dimensions that is controlled by a computer. This allows the piece to move past the drill bit, which is controlled vertically by the computer. If the bit is just below the surface of the piece as it is moved, a line will be cut out of the copper cladding. If the piece stops and the drill bit goes down, a hole is drilled through the board where a component will go. This whole setup, while complicated, allows for nearly complete automation of the process and can produce very nice boards.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com3tag:blogger.com,1999:blog-16143549.post-1131636091849186542005-11-10T07:10:00.000-08:002005-11-10T07:21:48.843-08:00Computerized Christmas LightsYup, you heard (read?) right... computerized Christmas Lights! Why? Why not?! The last two Christmas seasons I have gone to see a very interesting light display in Winona Lakes that was put together by one of their Computer Science professors. It consists of a lot of strands of christmas lights - some on trees, but most on a large conical "Christmas Tree" that is against his garage. All of the lights are controlled by a computer running Linux and some custom software (actually, custom <i>programming language</i> - the guy <i>is</i> a CS prof...) that controls when the lights are on and off, which allows the tree to change colors and display patterns. All of this is set to music that is broadcast via a small FM transmitter, so you can tune in on your car stereo to hear it.<br /><br />This got me to thinking about how cool it would be to build my own version, on a much smaller scale at first. I looked around and came across a website that dedicates itself to and calls itself <a href="http://computerchristmas.com/index.phtml?link=home&TempRefer=computerchristmas.com">Computer Christmas</a>. The layout leaves a bit to be desired, but there are plenty of circuits and great ideas available. This <a href="http://computerchristmas.com/?link=how_to&HowToId=7">circuit</a> provided the inspiration for me to begin putting my own together using twelve of this circuit and the twelve output lines of the (wait for it...) parallel port. I've had all of the parts ordered since summer and have just been working on getting around to putting them all together. This is where <a href="http://danwake.blogspot.com/2005/11/great-site-with-sadly-only-one-product.html">Monday's post</a> comes into play - the boards that they sell work with the parts I already have, making assembly very very easy. <br /><br />So - be watching for further updates on this project, and hopefully around Christmas time some pictures/videos of my light display.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1131415989081294212005-11-07T18:02:00.000-08:002005-11-07T18:13:09.093-08:00Great Site with (sadly) Only One ProductI was researching some equipment for work and came across <a href="http://www.simpleio.com/">www.simpleio.com</a> which has an opto-isolated triac board that they sell in various different forms. First - there is a version with eight triacs and another with four. They also sell the same boards without terminal connectors for a substantial saving, kits that can be assembled (with and without terminal connectors), and just the bare boards that can be populated with your own components. As if this weren't enough - they also have the schematics and board layouts available to download for free! But wait, there's more! There's also <a href="http://www.simpleio.com/design/triacout/TriacOutSchematicNotes.asp">a section</a> with details about how the circuit and the individual components work. The whole feeling of the site can be summed up quite well in this from the schematic page: "I hope you like this enough to buy the boards (the triac output bare boards are fun!), but even if you don't buy from us, you may know someone who will." This looks to be an excellent site and I plan to purchase some of their boards for my own use - more on that later.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com1tag:blogger.com,1999:blog-16143549.post-1130383703788685222005-10-26T19:40:00.000-07:002005-10-26T20:30:07.443-07:00Add Another Display to your Computer<a href="http://photos1.blogger.com/blogger/6891/1521/1600/LCD.jpg"><img style="float:right; margin:0 0 10px 10px;cursor:pointer; cursor:hand;" src="http://photos1.blogger.com/blogger/6891/1521/320/LCD.jpg" border="0" alt="" /></a><br />Want a way to show a little more information on your computer without taking up any of that precious screen real estate and without shelling out the big bucks for another video card and monitor? A simple (and cheap!) <a href="http://www.electronic-engineering.ch/microchip/datasheets/lcd/lcd_data_sheets.html">HD44780</a>-based (or compatible) character display can provide all this with a little money and a little effort. Connections are fairly simple - there are eight data inputs to the chips which connect to the eight output lines of (you guessed it...) the PC parallel port. The next bit is a little tricky, depending on your display. Some displays run off of +5 volts which is quite easy to get - it is quite common on computers and is also easy to generate using an LM7805 voltage regulator. Others, like the one that I used, require -5v to run which isn't quite so easy to find or make. I found a handy little <a href="http://www.compuphase.com/electronics/inv555.htm">circuit</a> that uses the very common and quite useful 555 timer to convert an input between +6v and +35v to -5v.<br /><br />There is a lot of software out there for sending text to the display - from a Linux <a href="http://linux.softpedia.com/get/System/Operating-Systems/Kernels/">kernel driver</a> to a WinAmp <a href="http://www.winamp.com/plugins/details.php?id=143888">plugin</a> to all sorts of programs for displaying <a href="http://www.google.com/search?num=100&hl=en&lr=lang_en&safe=off&c2coff=1&client=safari&rls=en&q=HD44780+computer+information&btnG=Search">system information</a>.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1130370391756290792005-10-26T16:22:00.000-07:002005-10-26T16:46:31.763-07:00Circuit simulatorsA good way to test a circuit design without actually going to the trouble of buying the parts, putting it together on a breadboard, and then trying to troubleshoot it/buy new parts when it (almost inevitably) fails is to use a circuit simulator. One that I've used and like fairly well is a java applet that is simply called <a href="http://www.falstad.com/circuit/index.html">"Circuit Simulator"</a>. It has quite a few different components that it simulates and since it is java, it should work on any platform that supports java - MacOS, Linux, even Windows.<br /><br />I've used other simulators, but I can't remember what the names of them are at the moment, but I will check with some of my friends who have used them as well to see if they can remember specifics. Searching at the moment is proving fruitless... more to come later, hopefully...Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1130257288542863642005-10-25T09:15:00.000-07:002005-10-26T16:17:12.623-07:00Small, Cheap Digital CameraWhile shopping at Wal-Mart the other day, I came across a little digital camera that was advertised as being "keychain-sized". The resolution and number of pictures is equivalent to what the camera I used in <a href="http://danwake.blogspot.com/2005/10/timed-digi-cam.html">this project</a> but it is about an eighth the size and uses only one AAA battery instead of three. Using this for kite-based photography would allow for flights in lower wind speeds. There a couple of issues that I can think of with using this camera instead of the larger one. The first is that the power on-board the camera would only be 1.5v instead of 4.5v, so you would need another source of power for the 555 timer, perhaps two 3v lithium watch batteries. The other concern I would have is that it might be <i>too</i> light and get tossed around more easily in the wind, but I'm sure there's a way that this could be alleviated.<br /><br />I've looked around on Wal-Mart's <a href="http://www.wal-mart.com/">website</a>, but I can't find the camera that I saw, but <a href="http://shopping.discovery.com/stores/servlet/ProductDisplay?catalogId=10000&storeId=10000&productId=58657&hp=HPA&hpnavid=A3_8spot_KeychainCam_pr">here's</a> a similar one that I found on another site.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com1tag:blogger.com,1999:blog-16143549.post-1130015628334528752005-10-22T14:01:00.000-07:002005-10-22T14:13:48.340-07:00Another Site with Good Circuits<a href="http://www.aaroncake.net/circuits/index.asp">Here</a>'s another good site with some interesting circuits and even some board layouts for etching your own (I've yet to post that tutorial - that will be coming soon - promise!). The circuits are categorized into light & LASER, sound & radio, power supply, auto, computer, and phone circuits. There are quite a few that look to be really interesting and useful; I'm considering making the automatic headlight dimmer, for example. Looks to be a good resource for finding intersting circuits to build and he even gives some advice on another page for where to get parts.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1129589494650085272005-10-17T15:47:00.000-07:002005-10-17T15:51:34.650-07:00Chip Directory - A Handy Resource<a href="http://www.xs4all.nl/~ganswijk/chipdir/">Here's</a> a handy resource that I found - a chip directory that lets you search for information about just about any integrated circuit you might come across. This would be very useful for finding out pinouts, looking up manufacturers, or discovering exactly what that weird chip does that a particular circuit calls for. Having played around with it for a little while, it looks to be pretty good if a little weird at times, but all-in-all seems to be a pretty good resource that's worth bookmarking.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1129589230368506162005-10-17T15:28:00.000-07:002005-10-17T15:47:10.376-07:00Timed Digi-Cam<a href="http://photos1.blogger.com/blogger/6891/1521/1600/IMG_13211.JPG"><img style="float:left; margin:0 10px 10px 0;cursor:pointer; cursor:hand;" src="http://photos1.blogger.com/blogger/6891/1521/320/IMG_13211.JPG" border="0" alt="" /></a><br /><a href=”http://www.andrewkilpatrick.org/mind/aerial_photography/stylecam_rig/”>Here’s</a> a little project that I found a while back when looking for a way to take aerial photographs from a kite. I needed a way to trigger the shutter for the camera for the ground, and had toyed with the idea of some sort of radio-based triggering, but decided to go with a simple timer. The circuit connects to a simple, low-resolution digital camera (which is not the Stylecam mentioned in the article, but similar enough to work) that I got for Christmas a few years ago. I soldered directly on to a few points of the camera - +5, ground, and one side of the push-button that operates the shutter. The heart of the circuit is the classic <a href=”http://www.doctronics.co.uk/555.htm”>555 timer</a> which sends a pulse out roughly once every five seconds that lasts long enough to simulate pressing the push-button. With the capacity of the camera limited to 20 pictures, this lasts for a little over a minute and a half – usually long enough to get the camera and kite up to a decent height for interesting pictures.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1129588062560981352005-10-15T15:25:00.000-07:002005-10-17T15:27:42.566-07:00Simple Project: SNES RF-AdapterHere’s a simple little project that came out of necessity – I had an extra <a href=”http://www.nintendo.com/systemsclassic?type=snes”>Super Nintendo</a> that I wanted to give to my girlfriend, but none of the accessories for it – controllers, AC adapter, and… an RF-adapter to connect it to a TV. Long story short, I got everything else except the adapter and didn’t want to have to pay big bucks to get a “real” adapter from <a href=”http://www.ebay.com/”>eBay</a> or used from a used-game place. I decided that it couldn’t be terribly difficult to make, and that this could be an interesting little project.<br /><br />My first step was to open the existing adapter from my Super to see what makes it tick. It turns out that there really isn’t too much to it, just some circuitry to handle the automatic switching of the signal from the antenna or from the Super. Since this didn’t really work very well to begin with (the picture from the antenna was often fuzzy), I decided to not try to copy this circuit, but instead to use an RF switch I had lying around from a previous cable-TV installation. I soldered and heat-shrunk the cable from an RCA-style plug onto one of the inputs of the switch and left the other side open for connection to an antenna.<br /><br />That’s it for construction – just a few cables in the right spots and it works like a charm. This just goes to show that not all projects have to be difficult to be useful!Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1129221341950698902005-10-13T09:31:00.000-07:002005-10-13T09:35:41.956-07:00Live Site Post"Hidden" Lab on Campus<br /><br />There are many labs around campus, but I one that often has some empty machines that I don't think is as well-known as say, the one in the basement of Northside Hall or the multitude that are available in Darwin and Wiekamp Hall is the one that is to the left of the circulation desk in Schurz Library. It is sort of tucked away and therefore not as visible as the others, but the signs are there for it. There are about 20 PCs and Macs available, with a printer and some scanners as well. It does get full sometimes, but often times it's not too hard to find a free machine.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1129159459472259782005-10-12T16:18:00.000-07:002005-10-13T08:13:18.240-07:00Wikipedia TopicI have definitely decided that I will do my Wikipedia topic on my employer, <a href="http://www.tenneco-automotive.com/">Tenneco Automotive</a>. Right now, I don't know a whole lot about the history of the company, other than it has been around for quite some time. I know that Tenneco owns the brands Monroe, Walker, Clevite, Gillet, Ranch, DynoMax, Fonos, Fric-Rot, Kinetic, Thrush, and DNX. Whew! Also - according to the site, we have "74 manufacturing facilities located in 22 countries and on 6 continents". The company has been publicly traded on the NYSE since November 5, 1999 under the symbol TEN and is a $3.5 billion company with 19,600 employees. I will try to find out some more information about the company on Friday when I can pick the brains of some of the folks who have been around for a little while...Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1129045440444939712005-10-11T08:25:00.000-07:002005-10-11T08:54:27.986-07:00Schematics Galore!Once you have your bench <a href="http://danwake.blogspot.com/2005/10/well-stocked-bench-mark-ii.html">set up</a> check out <a href="http://www.commlinx.com.au/schematics.htm">this site</a> for all sorts of schematics for a variety of different circuits - from Alarms to Video projects and everything in between. Not all of the links work so you'll have to kind of poke around for a good one, but there are usually multiple links to similar projects.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1128992549610383782005-10-10T17:57:00.000-07:002005-10-10T18:02:29.610-07:00The Well-Stocked Bench (Mark II)<a href="http://danwake.blogspot.com/2005/10/well-stocked-bench.html">Yesterday</a> I mentioned some of the essentials for a well-stocked electronics bench. Poking around a bit, I've found a nice <a href="http://sound.westhost.com/tools.htm">write-up</a> by Andrew Walmsley and edited by Rod Elliott which goes into a lot more depth than my little post and further discusses how to use some of the equipment they suggest. He also lists some cautions when working with electricity that you would be wise to follow! Definitely worth a look for those considering embarking on this strange and wonderful hobby...Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1128992249516103122005-10-10T17:40:00.000-07:002005-10-11T08:24:13.063-07:00Drive Safely With Your Cell Phone<a href="http://mypage.iusb.edu/~dawakefi/finished_product.jpg"><img style="float:right; margin:0 0 10px 10px;cursor:pointer; cursor:hand;width: 320px;" src="http://mypage.iusb.edu/~dawakefi/finished_product.jpg" border="0" alt="" /></a><br />Or: "Avoid that Crick in the Elbow from Long Conversations While Driving"...<br /><br />So I realized that when I talk on my cell phone and drive (tsk tsk, I know) I do tend to get a sore elbow after a while, and also I have a tendency to lean with said elbow on the armrest causing me to tilt my head which probably isn't a good driving practice. To top all of this off, if I'm holding the cell phone, that hand is not available to do other things like hold the wheel, adjust mirrors, play with the radio, and... um... eat breakfast. Not that I'd ever do that. So - I thought about this, and have seen some of those <a href="http://www.hitequest.com/Projects/buy_fm_handsfree.htm">gadgets</a> on TV that promise to pipe your cell audio through your stereo via a doofy-looking FM transmitter that plugs into your cigarette lighter. These, in addition to looking doofy, are more than I want to pay for what they provide. I decided that since I already have an adapter to run audio from a headphone jack into my tape deck and since I have a microphone from a headset that I never use that I would make a little plug that would send the audio from the microphone into the cellphone and the output from the cellphone into a headphone jack. To do all of this I stopped at <a href="http://www.radioshack.com/">Radio Shack</a> after work and bought a 3/32" stereo plug with solderable contacts and a pair (that's how the packages come... I've now got a spare for another day!) of 1/8" stereo headphone jacks. I then took apart the headset I already had and determined which wires go where with my multimeter. The "sleeve" of the jack (the part closest to the wires) is ground for both the microphone and the speaker. The center goes to the other side of the speaker and the tip goes to the other side of the microphone. I then soldered the microphone to the connections for ground and tip and the headphone socket to the connections for ground and middle. This accomplished, I tried it out by clipping the microphone to my visor and plugging the input to my tape adapter into the headphone jack and dialing a number using voice-dial on the phone. First time - worked like a charm! It's kind of cool really to hear the cell audio going through the car stereo and being able to dial and talk without taking my hands off of the wheel except to answer and press and hold the voice-dial button.<br /><br /><i>I'll add pictures later - currently on a lousy dial-up connection...</i><br /><i>Picture added - I have no macro lens for my camera, so the "in progress" ones look terrible</i>Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1128903493492812402005-10-09T16:24:00.000-07:002005-10-09T17:18:13.496-07:00Interesting Electronics-Related SiteSurfing around, I found the homepage for <a href="http://www.underthepier.com/">"The Under the Pier Show"</a>, that is, to quote the site's author "A MAD COLLECTION OF HOME-MADE SLOT MACHINES & SIMULATOR RIDES ON SOUTHWOLD PIER, SUFFOLK, UK". This really is the best description for what all he has built for his venue. The machines are all hand-made and incredibly well-done. The ideas that he has come up with and implemented are very interesting and well thought-out. If you have a few minutes, I would suggest poking around for a while. The site is not the best-organized in the world, and some projects are not available from the main page, but clicking the various links throughout the other descriptions should get to the pages for most of his projects - it's definitely worth looking around!Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1128900255174209882005-10-09T15:33:00.000-07:002005-10-09T16:24:15.180-07:00The Well-Stocked BenchAs a continuation on my previous post about <a href="http://danwake.blogspot.com/2005/09/where-to-buy-electronic-components.html">where to buy components</a>, I thought that I would write a piece about what should be on a bench for those looking to start building fun and exciting circuits.<br /><br />First - equipment. A good <a href="http://en.wikipedia.org/wiki/Multimeter">multimeter</a> is a must for testing and diagnosing circuits (believe me - this is where a <i>lot</i> of time is spent!). I would suggest getting a digital, autoranging multimeter for the convenience that both offer - digital since it's easy to read and reasonably foolproof and autoranging so that you don't have to worry about what the voltage/amperage levels are before you put the meter on. A multimeter should be able to measure <a href="http://en.wikipedia.org/wiki/Resistor">resistance</a>, <a href="http://en.wikipedia.org/wiki/Current_%28electricity%29">amperage</a>, continuity, and <a href="http://en.wikipedia.org/wiki/Voltage">voltage</a> at the least and some of the better ones can measure <a href="http://en.wikipedia.org/wiki/Capacitance">capacitance</a> and other useful things. For digital circuits, a <a href="http://www.uoguelph.ca/~antoon/circ/probe1.htm">logic probe</a> is handy for showing digital levels when testing and can be bought or fairly easily built. <br />When constructing a circuit, a <a href="http://www.seas.upenn.edu/ese/rca/funstuff/soldering/soldering.html">soldering iron</a> is a must - my current setup is a generic 35-watt pencil type iron with a 15-watt tip from <a href="http://www.radioshack.com/">Radio Shack</a>. The mismatch in wattages is intentional - I like the heat output from a 35-watt iron, but I like the fine tip that comes with the lower wattage tips. This is not dangerous to do - the tip is just a piece of pointy metal. I have found that when it comes to solder, a 60/40 lead/tin solder in the smallest diameter you can find is quite good for most applications. Along with the soldering iron, I would suggest getting a desoldering iron. As its name would imply, this is similar to a soldering iron, except that the tip is hollow and connected to a rubber squeeze-bulb to remove solder from a board. This can have dual-applications - one for fixing mistakes and the other for the removal of components from existing circuit boards, which can be a great way to get parts cheap!<br />Good lighting is a huge help when working on tricky circuits, especially ones with many small components in them. A setup with two standard fluorescent light fixtures spaced a couple of feet apart overhead will help to eliminate shadows and provide clean, even white light to the bench.<br /><br />For components - the more the merrier, really! A good collection of resistors in various resistances as well as a good stock of film and electrolytic capacitors is almost always useful - there are many times when a circuit will require some odd resistance or capacitance and it's nice to have all of these handy. They are cheap enough to stock up on without breaking the bank and will most likely show up in one form or another in most circuits. LEDs and standard diodes are also good to keep a decent stock of - again they are fairly cheap, and many circuits will use them - LEDs are especially useful for diagnosing digital circuits or for building into them to show logic levels at key points. For the digital enthusiast, a must-have in nearly any circuit is the <a href="http://www.national.com/pf/LM/LM78M05.html">LM7805</a> 5 volt voltage regulator. This will take input from a power supply ranging from ~6v to ~35v and convert it to 5 volts - the standard logical high level used by most chips. Caution on these - they do tend to get hot when they're running, especially when input is toward the high-end, so you might want to stick a <a href="http://headphone.fileservice.co.kr/sijosae/Gallery/Tip/HeatSink-2.jpg">heatsink</a> on it. Common digital ICs will include the 7400 NAND gate, 7402 NOR gate, 7404 hex inverter, 7408 AND gate, 7432 OR gate, 7486 XOR gate, 7474 D flip-flop, and 7486 J-K flip-flop for a good starting point. Datasheets for all of these can be found through <a href="http://www.hanssummers.com/electronics/datasheets/">this site</a>.<br /><br />For prototyping circuits, a <a href="http://www.iguanalabs.com/breadboard.htm">breadboard</a> is a good way to play around without setting anything into stone (or solder as the case may be...). Once a circuit is tested and working, it can be made more permanent by moving it over to a <a href="http://www.winfordeng.com/products/cat_perfboard.php">electroncis perfboard</a>. This is similar to the breadboard in layout, but is made of formica and has copper cladding on the back to solder to. For making a lot of circuits, or for making a nice-looking board, etching is the way to go. More on this in a later post, as there are many ways to do this...Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1128897002304462412005-10-09T14:52:00.000-07:002005-10-09T15:30:02.313-07:008x16 LED Matrix<a href="http://mypage.iusb.edu/~dawakefi/LED_Matrix.jpg"><img style="float:left; margin:0 10px 10px 0;cursor:pointer; cursor:hand;width: 320px;" src="http://mypage.iusb.edu/~dawakefi/LED_Matrix.jpg" border="0" alt="" /></a><br />Here's a project that I'm dusting off from a couple of years ago - a homemade 8x16 LED matrix. Basically this is a small version of the type of <a href="http://www.adaptivedisplays.com/Pages/commercial.htm">sign</a> often used for displaying messages along the sides of roads, in stores, etc... The resolution is not great and it's not really wide enough to be totally practical, but it is a good proof of concept and an <i>excellent</i> way to hone the 'ol soldering skills.<br /><br />The device is really quite simple from the hardware point of view - it consists of 128 LEDs that are arranged into a matrix of sixteen columns and eight rows. The cathodes of all of the LEDs in a column are all tied together and are only grounded when the circuit is completed by a transistor. Similarly, the anodes of all of the LEDs in a row are tied together and are only supplied current when completed by a transistor. The transistors grounding the columns receive their signals from a <a href="http://www.alldatasheet.com/datasheet-pdf/pdf/FAIRCHILD/74LS154.html">74LS154</a> <a href="http://en.wikipedia.org/wiki/Demultiplexer">demultiplexer</a> that has four digital inputs and sixteen digital outputs. The signals must first pass through a <a href="http://www.priory.bromley.sch.uk/students/electronics/reference/4069.htm">4069 hex inverter</a> since the output from the demux is opposite of what we want (selected output is low, others are high which is not what we want). Only one column can be grounded at any given time. The input to the demux comes from four of the output pins of a PC parallel port. The rows are driven using the other eight output lines from the parallel port so that any combination of rows can be high at any one time.<br /><br />This is it for the hardware - everything else is done in software. For this project I have written the test software in Microsoft QuickBASIC 4.5 but have ported the code to C++ so that it can run well on most architectures. Because only one column is grounded at any given time, I had to rely on persistence-of-vision to make it appear that all columns are lit when needed. This is accomplished by looping through all of the columns very rapidly and setting the output on the rows as necessary when the proper column is grounded. This results in a fairly smooth looking picture without too much flicker. The most common application for this sort of sign was the first program that I wrote for it - displaying a scrolling message. Due to the limits on the width (approximately 2.5 characters) scrolling is required to display all but the shortest messages. The software for this is quite simple - just an array to hold all of the row values (I developed a simple font that converts characters to the correct row values) that gets output to the display. When it comes time to scroll, simply rotate the array so that position 1 of the array corresponds with the first column on the display.<br /><br /><a href="http://mypage.iusb.edu/~dawakefi/matrix.bas"><i>Sourcecode (QB)</i></a><br /><br /><i>Schematic</i> - I cannot find the schematic that I based mine on that I was going to post here, and I haven't yet drawn one for what I built - I'll try to make this link useful soon...Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0tag:blogger.com,1999:blog-16143549.post-1128299078496507002005-10-01T14:09:00.000-07:002005-10-02T17:25:59.516-07:00Put Your Electronics Knowledge to Use: Become a Ham!Sorry if this sounds a little "sales"ish...<br /><br />One good way to put electronics knowledge and love to use is to become an <a href="http://wireless.fcc.gov/services/amateur/about/index.html">amateur radio operator</a> (<a href="http://en.wikipedia.org/wiki/Ham_radio">ham</a>)! This is a very interesting field that allows you to <a href="http://www.dxing.com/">talk to people the world over</a>, assist in <a href="http://www.races.net/">emergencies</a>, <a href="http://www.kent.net/ve3rdn/ve3rdn.html">send pictures</a>, and much much more. This is considerably different from just using a CB radio to talk to people - first, a license from the <a href="http://www.fcc.gov/">FCC</a> is required so not just anyone can get on - also, the number of available frequencies and the power allowed on each are consierably greater than anything available without a license.<br /><br />The best way to get started would be to take some <a href="http://www.qrz.com/p/testing.pl">practice tests</a>, read <a href="">some</a> <a href="http://www.amazon.com/exec/obidos/tg/detail/-/0945053274/qid=1128298575/sr=8-1/ref=pd_bbs_1/104-1716509-4290328?v=glance&s=books&n=507846">books</a>, and find a <a href="http://www.amazon.com/exec/obidos/tg/detail/-/0945053274/qid=1128298575/sr=8-1/ref=pd_bbs_1/104-1716509-4290328?v=glance&s=books&n=507846">local test</a> time and location. The cost of taking the exam is typically less than $15 and there are only 35 questions, so it shouldn't take more than half an hour.Anonymoushttp://www.blogger.com/profile/08112772597886497529noreply@blogger.com0