Freeside Atlanta

Since the last installment, I've finalized the initial PCB design and sent it off to Seeedstudio  for fabrication. I've never designed a through-hole (TH) construction board before but in general all the same rules apply to SMD and TH boards I believe. 200W 0.1Ω load   30W 1Ω load 10x10Ω 3W in || 25 turn trimmer pot I changed up a few things during the PCB design phase of this project that I thought would be interesting to mention. I added a pair of trim pots to design. One trim pot reduces the maximum voltage going into the first op-amp stage. The second is the in the feedback loop of the first op amp stage. At maximum resistance, 3000Ω to GND (R2 of the voltage divider), with the 820Ω R1 (there for its role as a low pass filter in addition to the voltage divider), I should see a 27% voltage gain. Turned down to 0Ω, that pot creates a situation where the output is the high output voltage of the op-amp (essentially infinite gain). Something like 8V for the op

While working on the constant current load project I found that while nice, the multiple turns required to turn up the power up was a little annoying when you just wanted to hurry up and get to a high value. The standard solution is to have a "fine" and "course" knob. Since I designed the input in the digital realm it seemed like software was the obvious solution. Why not sense the speed the user is turning the knob and extrapolate the pace of change based on that input. It seems intuitive to me. I implemented it as a little C++ library that you can drop into your arduino/libraries directory. Here is the most trivial implementation of the library. #include <RotaryEncoder.h>; RotaryEncoder encoder(A0,A1,5,6,1000); void setup() { Serial.begin(57600); } void loop() { int enc = encoder.readEncoder(); if(enc != 0) { Serial.println(enc); } delayMicroseconds(5); } Inside the library, the code counts the number of the sequential clicks in one

The Off-Road Wheelchair is a device that will enable a person of limited mobility to experience the outdoors. Freeside Atlanta is interested in putting our engineering skills to the test, and showing the world we can create anything we put our minds to. We have the space, the tools, and the talented people to make this happen - we just need your help to purchase the materials and make this project a reality. The idea originated with Robin Beattie, who participates in regional Burning Man events, like the Alchemy Arts Festival here in Georgia. The festival takes place on a farm, with terrain features like gravel, light mud, paths with tree roots, and moderate changes in elevation. The Off-Road Wheelchair will be designed to traverse this environment, enabling Robin to get around in a place that would normally be closed off to her and others with limited mobility. Upon completion, the Off-Road Wheelchair designs and notes will be released under a Creative Commons (by-nc) license, w

I just got my first oscilloscope. Complex analog circuits are now possible. As I mentioned in my last post, I working on a power distribution unit (PDU) for motorcycles, cars, and other DC applications. The project is very close to the testing phase and that means I will need to run this device at precise power levels and at precise temperatures. The testing protocol also includes vibration studies, but today we are just going to talk about precision current testing. This can be done many different ways. You can just put a resistor to ground and use Ohm's Law to tell you how much current you are burning. If you want to change the current in use though, you will have to change the resistor. That is not very handy if you want to test your power supply at multiple currents as you will need a lot of different resistors. Since my system is running at about 14V and I am talking about 15A of current, I'll need some pretty beefy resistors and those are expensive. Instead

I've been working on a large project for a few months now. It's a DC power distribution unit, and as you can imagine it has need for relays. I've got the thing setup to accept cards to can perform many uses both input and output. One of the many cards I've designed for this system (dual low-side switching relay, 5V, 12V, audio sensor etc..) is a dual high-speed 12V solid state relay card. Rendering of PDU and fresh pile of PCBs from Circuitmart This is a photo of the relay on a breadboard.  single channel of dual high-speed 12V solid state relay on breadboard This is the card from both sides. The "empty" space is used for thick and wide traces to carry current. These will be built with 6oz copper and can source 23A @ 330W in theory. I've only pushed them to 100W so far but they showed no meaningful rise in temperature so I think I am on the right track. By the numbers, they are right where they should be. Because these cards are small and

I found myself needing a 480W power supply to test a high current project I was working on. A 500W bench/lab power supply will set you back $100s so I figured a PC power supply was the cheapest bet. For $80 you can get a Wonhunglow brand. I checked ebay and found Dell 500W server power supplies CHEAP. Like $2 cheap. I acquired a couple and figured out how to turn the thing on by shorting 3 pins together. Then I designed a simple little 4 rail power supply PCB and had it built by OSH Park. This power supply outputs 12V and 5V and 4V. I didn't have any use for the 4V so I skipped those pins but did add a 500mA 3.3V LDO to my board so I have 3.3V, 5V, 12V, and GND rails available. I left a large section of the solder mask missing so I could solder on some more current carrying capacity and called it done. I used a DPDT switch to short out the 3 pins required to turn on the 12V rail and added a little LED to indicate that the 3.3V regulator was running and put a small current limitin

A little over 2 weeks ago, we at Freeside Atlanta launched a series of classes on Meetup on everything from Linux to 3D Printing. They've been a huge success so far! Our 3D Printing class, shown above, was taught by 3D Printing Expert Anthony Aragues. We had 11 students sign up for the first class, where they covered the recent iterations of hardware and software and how to use them. In fact, every single class that we launched filled to capacity. Intro to Linux, Intro to Electronics, Intro to Arduino, CNC, and 3D printing. Thank you to all of the Teachers and Students that made this little experiment such a success! Because of how well this first round went we'll be launching more classes and workshops soon, so stay tuned!

This post extends the previous post . Source Code Released! http://code.google.com/p/arduino-sharp-memory-lcd-gfx-library/ I've got a little reflow oven simulation running on the LCD. I think its going to be great for the reflow oven project. The source for the sketch in the video is attached below. The library now does vectors in addition to text and bitmaps. I am now extending the Adafruit GFX library so I can use those vector drawing routines in addition to my PGM space bitmaps. I still need to clean up the unnecessary banging I am doing on one pin. I'll post up the code on the interwebz for all to use once that is cleared up. I need a darn oscilloscope to inspect that pin! If you need an early copy of the library and you don't know how to contact me, PM me from the youtube video. #include #include "SharpMemoryLcd.h" SHARPMEMORYLCD lcd; void setup() { Serial.begin(9600); lcd.LcdInitialize(); lcd.LcdAllClearMode();

Update: Arduino Library Released If any of you guys were at Freeside this weekend, you would have seen me staring into the oscilloscope trying to make heads or tails of its output and comparing that to a couple of datasheets. One of those datasheets was for the Atmega328P microcontroller that is on the Arduino UNO, the other was the Sharp Memory LCD . These are cool because the are ultra low power 6uW and have extremely high contrast. The Sharp datasheet isn't what I would call straightforward, at least for the uninitiated (whom I count myself among). The power up sequence was pretty clear but once it came to pushing pixels it got a little vague. Really it was just a bunch of waves on the sheet. One of the waves is a constant 5-60Hz pulse. That is the sort of thing that would be very irritating to create if you are bit banging on the main loop of your program, so I needed to get the AVR to pump that out in an automatic way. Researching the interwebz and reading the Atme

During one of the last projects I was working on, I found that the first programming jig I made had a serious draw back. It could only put the #1 pin of the programmer in two of the four corners. That meant that I could only program my board from one side. That was fine until I assembled the project in it's case. At that point, reprogramming was a difficult task that required disassembly, something I never considered when I designed the item and as it turned out it was almost impossible to do without destroying it. Annoying! Three weeks ago I decided I wanted to flash some new firmware on my motorcycle remote so I could use it to put a GPS on my Kindle Fire. That meant I needed take it apart and risk destroying it. Not an exciting prospect. Then I thought, why don't I just build another programming jig like the last one only upside down. That seemed like a winner, because it was fast, but I didn't have any more 2x3 ISP headers. Bah! Since I needed to wait on a shipm

Inspired by THIS !SAFETY! This is some dangerous stuff. It will mess you up.   Zn + 2 HCl          > ZnCl 2  + H 2

This giant masonry blade has been sitting around Freeside forever: Rust and dust are indicators of abandonment. Please make use of the rusty and dusty. Note the diamond tipped edge I KNOW!  Let's make a giant scythe for my Halloween costume!!  (Never too early to plan)

Freesider's are evermore professional printistas of sorts.  As our sprints are ramping up, there seems to be a growing interest in "organic modeling".  Things often found in nature fall into this category for CAD artists. Here is a recent Thingiverse upload, which was made from some very simple modeling techniques in Newtek's Lighwave 3D application.  A little goes a very long way, indeed. per Thingiverse.com: There are 26 proper bones in the human foot; 28 if you consider the sesamoids of the 1st metatarsal phalangeal joint complex. That's over 25% of your body's total musculo-skeletal anatomy, hitting the ground every time you go for a walk or run! Quite impressive, really. Read More: en.wikipedia.org/wiki/Foot learnbones.com/foot-bones-anatomy This anatomic foot model was designed in Newtek's Lightwave 3D, as part of the podcast @ YouTube.com/DrGlassDPM Anatomic study models can be quite expensive, search.anatomywarehouse.com/

Published in the May issue of the Journal of Foot and Ankle Surgery : " A Novel Combination of Printed 3-Dimensional Anatomic Templates and Computer-assisted Surgical Simulation for Virtual Preoperative Planning in Charcot Foot Reconstruction ." This collaboration of specialties represents an undertaking by members of Freeside Atlanta , Southern Arizona Limb Salvage Alliance , and The Podiatry Institute .  Charcot foot reconstruction remains on of the most challenging procedures in foot and ankle surgery.  These procedures are often lengthy procedures which can be riddled with complications. With the help of Freeside Atlanta Members, institutional researchers used open source Osirix Image viewer and 3D Software such as Newtek's Lightwave or Blender to create simulated surgical reductions as well as 3D printed templates.  Freeside Atlanta members assisted in providing 3D printing solutions and know-how to the project. Experimental test prints were done on a M

OH look! A package! I wonder who it is from? Maybe it is something about the Soapbox race? Looks like it Oh Man! Red Bull and a note card saying "thanks but no thanks."   Don't they know I prefer diet?!?

Freesiders are continually tinkering with robotics and other such machinery .  Many of these embedded processors and firmware are becoming open source and every-more diversified in the wake of the modern Maker movement . One notable boost to the hackerspace arsenal is the Arduino (an like platforms).  This offers designers an incredible power to devise not just individual devices but even the emergence of complex, integrated systems . This evolutionary pace of modern technological systems may be significantly faster the biologic system development, but there may be a few well learned tricks yet to be mastered.  It seems that studying how nature has managed to solve many development challenges will aid in designing robotics, where efficiently counts just as much. One  challenge, that is particularly interesting, is data processing.  Artificial intelligence is labored with processing data and producing a meaningful and useful output.  When considering the increase in sensory

After seeing Joshua Oster-Morris with this little box I asked him to write a post for us on how it came it to being. Worth the read. Dateline: San Francisco, May 10 2011: Google I/O 2011 opens up with much fanfare and I, a lowly “software guy”, sit down to listen to a couple of sessions on Google Web Toolkit. I have been using it to develop a motorcycle navigation website ( http://www.dualsportmaps.com ) and its always good to try to pick up a few new tricks of trade. These are mainly esoteric talks about development tools, but there is also one about a new API called RequestFactory that allows state aware communication between client and server characterized by its low bandwidth. They discuss how it might be handy to use as a protocol for communicating with Android devices. To that, my ears perk up and I make my best impersonation (imdogination) of Scooby-Doo. I have been doing a little Android development for personal projects, I have an extensive craft cocktail recipe book that

I was looking for ideas for tools to put in the little blue tool box I have been refinishing. I am giving this to a kid I have been working with and I was wondering if people had ideas for what tools a teen should have. What tools would you have wanted when you were a kid? What tools are you always needing? Here is what I have so far: Small hammer Metric and standard socket set Metric and Standard Allen Wrenches standard screwdriver bits and small screw driver. Small hand saw with switchable blades. Three different types of pliers.

In the last meeting of the Entrepreneur discussion group, we talked about business plans for our different ideas. Most businesses (Profit/Non-Profit, Product/Service...) that require some level of investment, fit into a similar planning pattern. We looked over one planning tool that I developed in Excel as an example of that pattern, which is then reflected in the example business plan that I posted to out Dropbox share (email me if you'd like access). The model works by developing the product and estimating it's price and market potential ( revenue projections ). Next, you develop the cost model ( bill of materials, equipment, facility, labor, administrative ). These costs are allocated by product (or service) and together, the revenue and cost projections form the key financial data ( Annual Operating Expenses, Pro-Forma Income Statements, Cash Flow Analysis, Breakeven Analysis By Product, Working Capital Requirements ). All of these are based on research and best-gues

Join us a Freeside next Thursday for an Introduction to Arduino Class. The class will be aimed at the basics of Arduino Programming, so some programming experience in any environment would be preferred, but is by no means necessarry. We will even have a limited number of Arduinos and Computers, however if you have the ability, please bring your own laptop and Arduino to work with. Location: Freeside Atlanta Time: 7:30 - 10:00 pm E-Mail: freesideatlanta@googlegroups.com

Just finished the Saturday series of welding classes at My Inventor Club. Matt from Freeside taught this one, but Shane from MIC does a series too. Here's Newt on the MIG while Charlie and I are playing around with aluminum on the TIG. Gloves and trendy jacket belong to the house, I just had to bring the glasses. Ear plugs may be a good idea too. Here I am, grinding down a piece for an ugly, abstract sculpture to practice on. All in all, we learned and then got to play with Oxy-Acetelene welding and cutting, grinding, portable band saws, MIG, Stick, TIG, and cut-off wheels. I came in with no experience and left with at least enough knowledge to not burn my own eyes out. According to Matt, they do the classes as 3 weeklies on Wednesdays, Thursdays, or Saturdays with 2-4 person groups. Drop a line on the Freeside mailing list if you're interested and they'll put together a class.

Sort of late to the show but here we go: Sign up today! http://wiki.freesideatlanta.org/classes/arduino

Next buildout is scheduled for March 3, 10:00 AM - 6:00 PM. For those not in the know, Buildout is when Freeside's members get for the purpose of making the space better, socializing, and eating food. Incidentally non-freesiders are more than welcome to show up, help, socialize, and then *maybe* become members afterward. Buildout's a great time for anyone to show they care for the space. If you have an idea for what needs worked on, please add it to the task list here: https://sites.google.com/site/freesideatl/build-out/to-do If you need something for said task, such as a ladder, please feel free to add it to the list here, and we'll try our best to see it shows up. https://sites.google.com/site/freesideatl/build-out/shopping-list Incidentally you might notice that many of these items don't have a responsible person. If you can please try to take ownership of at least one task. If you don't know what the task involves, it's possible no on else does either. Take

Stanford University will be offering free online classes this semester in a variety of fields. Students will receive a certificate of completion at the end of the class too. We at Freeside are forming a study/discussion group to help people through these classes and kick around ideas related to the subject matter, with a focus on the Technology Entrepreneurship classes. any of the classes are open for discussion, so feel free to grab what interests you. The group will meet on Saturdays at 6pm. Classes still haven't opened yet, so it's not too late to sign up for one. You can find the main class here - http://www.venture-class.org/ and the links to the other classes are at the bottom. The following classes will be offered this semester: Entrepreneurship      Lean Launchpad      Technology Entrepreneurship Medicine      Anatomy Civil Engineering      Making Green Buildings Electrical Engr.      Information Theory Complex Systems      Model Thinking Computer Science      CS 101  

I've been running Sprinter on a RAMPS 1.4 control board for my MendelMax since I built it a few weeks ago. This is the most common firmware in use, with the most community support. However there are other firmware options that are faster and more cutting edge, at the expense of having more bugs and a smaller user base. Today I switched to Marlin because I read that it handles acceleration between moves more smoothly, and can draw smooth arcs as well (a much more experimental feature). I chose this funnel as my test print because the cone and cylinders comprising it cover a range of arc sizes. On the left we have a print with Sprinter. There is a strong ridge at the layer change point near the left side, and additional ridges on every edge around the model. This print took about 40 minutes. In the middle is the exact same gcode run by Marlin. The edge ridges are gone, but the layer change ridge is more pronounced, especially on the cylinder at the top. This is much closer to wh

Zane, a member of the 7Hills Makerspace (http://www.7hillsmake.org/) to the north of us, has made this great light display for in front of his house. "...powered by a bluetooth enabled Arduino..." About $30 in parts and many hours with Zane's brain. http://zanecochran.com/entry.php?blog_id=335 Check out their group at http://www.7hillsmake.org/ and tell them Freeside says "Hello."

Our Dr. Glass and Sparr fight it out on who can create the fastest. From Dr. Glass: This was part of a "Day Project" at FreesideAtlanta.org In all fairness, Sparr and I became challenged in a Speed-Modeling contest. Me on Lightwave 3D and he on OpenSCAD. Sparr was victorious, but agreed to let me upload my model anyways. Thanks bud. I'm including this original as well as the Freeside Atlanta emboss.

Now that winter is coming to the northern hemisphere, getting up for work means getting out of bed before the sun comes up. In order to help the natural waking mechanism of light, I've decided to hack together a sunrise alarm clock on a shoestring budget. Part List: Arduino Real Time Clock Module ( http://www.sparkfun.com/products/99 ) 24xAssorted LEDs (In my case: 3UV, 2 Blue, 4 Red, 3 Yellow, 12 White) 24xResistors, 220ohm Solderless Breadboard Assorted wires 3x74HC595 shift registers A Shadow Display Box Frosting Spray To put this thing together I used Elco's ShiftPWM Library to control the 24 LEDs. You could go bigger, but I wanted this to all fit into the box. Personally, I had some PCBs from a previous project that I could fashion to make the LEDs easier to mount. Everything is hooked up like in the schematic: The "To SCL" and "To SDA" lines go to the Real Time Clock Module. The parts are all mounted to the backing board of the shadow display box lik

I am coming to freeside tonight. I should be there around 7.30pm I finished the hardware build of the new dual extruders from makerbot. Also their new interface kit build. I'll be installing them and doing the software work, calibration and hopefully a print or new design for the dual extruders before the night is up. Since I am going to be in the space anyway, I am going to open this to anyone who wants to attend. If you are bored or free try to stop by... Anyone interested in our progress on this is welcome to come read about it at http://www.linkreincarnate.com/

We will have some free freeside (free^2side?) keychains at our 3d printing presentation at Dragon*Con. In the meantime you can download the stl of the keychain here and a few of our logo stl files as well.

Here's a new video walkthrough of our space. Enjoy! Thanks to Engunneer and PeterP for hosting!

We will be having an open house/mini 3d printer meetup this Friday (August 19) from 4-8 pm. All are welcome to attend. We will be taking apart an UP printer for documentation/reverse engineering as well as tweaking a few others. Come on by and get your geek on!

Freeside Atlanta would like to invite everyone in the Atlanta area to a free introduction level class on open source 3D printing. Topics will include: Basic Printer Operation Various 3D printer designs including reprap and MakerBot OpenSCAD modeling software Common print materials So if you an just getting interested in 3D printing, or are already involved in 3D printing, stop by Freeside this Thursday night at 7:30pm. People already familiar with open source 3D printing are also encouraged to come and help teach or just meet fellow enthusiasts.

One of the costs of running an inkjet based 3D printer is that the cartridges have to be replaced on a regular basis. The Z400 and Z402 use Canon BC-20 ink cartridges which are readily available. There are currently two known ways of making these cartridges ready for the printer. The first method is to cut the cartridge in half, remove the foam inside, cut a Blue Falcon BD-50 Centrifuge tube in half, and epoxy it and a small O ring to the reservoir at the bottom of the cartridge. This is how the cartridges that are sold by Z Corp are made. An alternative method is two drill two holes in the cartridge, epoxy down some type of barb, and flush the cartridge. This is the method I am currently using in my Z402. Click below for full instructions and a few pictures of the process.

Hey, this is Pepper! We got a lot of clean up work today! We painted the kitchen and the back hallway. Work was done, accomplishments made! We also painted the back hallway wall a lovely chartruese (bwahaha) and took care some of the less seemly graffiti. Next buildout will be scheduled in the near future! :D

Miss all those Tuesday meetings because you don't live close and hate downtown traffic? Here's your chance to come check us out on a weekend! There will be plenty of members hanging out at the space doing stuff that interests us. (3D printing, metal pouring, etc). Stop by and hang out. All day Saturday (11Jun). Bring projects to show off, or projects you'd like some advice on. Bring friends and friends of friends! Weather permitting, there will be grilling. This event is FREE and OPEN to the public. Like all of our events, donations are appreciated. Children must bring their parents in order to attend. Add this event to your Calendar! Or, Upvote our reddit post. RSVP on Facebook

Freeside is a great space, but our kitchen could be charitably described as "needs work". The countertops are old, difficult to keep clean, and just generally bad. What the heck, we're a hacker space, right? Lets hack some countertops.