Shine on You Crazy KiCAD — and Other Tales from Chris Gammell

Chris GammellOn Monday July 17th, NERP will host Chris Gammell. Chris is an analog electrical engineer and product manager. He may be known to some of you as co-host of The Amp Hour, and as the charter member of Contextual Electronics. CE offers subscription based electronics courses with different levels of project-oriented learning and personal interaction with an instructor. The Amp Hour is a non-scripted off-the-cuff format show that usually airs every Thursday evening US time. It is the worlds largest and most respected electronics oriented radio show. Discussions range from hobbyist electronics to the state of the electronics industry, components, circuit design, and general on and off-topic rants.

At the NERP on Monday, Chris will present a free rendition of  the Contextual Electronics course titled Shine On You Crazy KiCad. NERP has talked about the open source electronic design program called KiCAD before, but this presentation is different. It’s designed for simplicity and fast execution to give a quick win for new users who follow along on their own laptops. The course is designed as an end-to-end art-to-part experience using KiCAD.  amphour logoWhen I say quick, I mean just 20 minutes start to finish to draw an electronic schematic and then translate the schematic into a printed circuit board PCB layout. (It’s possible to spend lots of days working on a complex circuit board design…) After that, the last step in the process will be for everybody who’s following along to pack up their KiCAD PCB layout files and send them off to OSH Park to actually be made into atoms and snail-mailed back to you. Chris’s demo board is a small, but useful add-on for a Raspberry Pi. The PCB is about 1″ square, so the cost at OSH Park is very small.

made with kicadEven if you don’t plan on actually making the circuit, go ahead and load up a copy of KiCAD so you can at least have a look and ask questions. It’s open source and free. Win, Mac, & Linux. Kicad is a pretty piece of software in my opinion, and I have a few good reasons for preferring it to Eagle (KiCAD’s freemium competitor).

Chris tells me there’s one thing that NERP might be able to help him with. Contextual Electronics is getting a new course for “absolute beginners” in electronics. This would be along the lines of “what do you need to know about electronics before even thinking of a course like CE”. When you first encounter a subject as broad and deep as electronics, it’s very hard to sort out the signal from the noise. You can spend a lot of effort on something that doesn’t matter while at the same time missing some small Rosetta stone or simple concept that’s perhaps in easy reach. conceptual electronics logoAfter we move past those first trembling steps, we can forget what it was like just building a knowledge framework. To make the best connections with absolute beginners, Chris wants to hear about your conceptual roadblocks or things you wish you’d known from long (or not so long) ago, and how they resolved (or didn’t resolve) themselves. I’m sure he’ll be happy to talk about it at NERP, but consider signing up for CE and visit the Building an absolute beginner course page and add your thoughts.

NERP is not exclusively Raspberry Pi, the small computer and embedded systems interest group at Pumping Station:One in Chicago. NERP meets every other Monday at 7pm at Pumping Station:One, 3519 N. Elston Ave. in Chicago. Find NERP and Pumping Station:One at /NERP-Not-Exclusively-Raspberry-Pi/­

Tags: Beagle Bone,electronics,embedded,hackerspace,NERP,Open Source,Pumping Station: One,raspberry pi,OSH Park,The Amp Hour,Contextual Electronics


07 2017

How to make a ring out of scrap copper.


I found a piece of scrap copper pipe and decided to make a ring out of it. Read the rest of this entry →


07 2017

NERP Can Reflow, and So Can You! [6-19, 7pm]

Surface Mount Technology is not a new thing. Eventually it’ll be the only thing because new MOSFETS, chips, and computer-on-modules are pretty much all SMT. If you’ve never  soldered SMT parts, you might be surprised at how easy it can be. In fairness, parts below a certain size can be challenging to solder, but with practice you can start big and go smaller and smaller as you get better. But where to start? At NERP on Monday, June 19th Drew Fustini will give a gentle introduction to SMT soldering.

Drew will be building   I can reflow! Badge  and showing the SMD Challenge board, also called the Unfortunate board because the 0201 resistor and LED will unfortunately make you nuts trying to solder them. The boards were made by , a commercial prototype and open source hardware board house. They have a huge catalog of boards designated as shared projects by their customers. You can buy those boards, or design your own in KiCAD or Eagle, and share them if you like.

Drew has a few extra reflow Badge boards if anyone wants to follow along. We’ll try to get enough parts together to fill the boards. Those parts are:

  • Q1 & Q2 – MMBT3904
  • R1 & R2 – 0805 100Ω
  • R3 & R4 – 0805 100kΩ
  • C1 & C2 – 0805 10µF

And two 0805 LEDs and a CR1220 battery clip.

Schematic diagram in Hackaday’s coverage of the I Can Reflow Merit Badge
NERP is not exclusively Raspberry Pi, the small computer and embedded systems interest group at Pumping Station:One in Chicago. NERP meets every other Monday at 7pm at Pumping Station:One, 3519 N. Elston Ave. in Chicago. Find NERP and Pumping Station:One at­


06 2017

NERP Tonite: MOSFETs with Ste!

Mosfets – They can be “on” — They can be “off” — They can even be in between! Tonight at NERP, entrepreneur, engineer, and really good teacher Ste Kulov will guide us into the world of mosfets. Metal Oxide Semiconductor Field Effect Transistors if you want to impress your friends.

N-Channel MOSFET [wikipedia]

Since mosfets are a wide and deep subject, I asked Ste where he wanted to focus his talk. With great economy of words, he said it better than I could.

“Most of the generic stuff, fairly quickly.  A few simple examples I was probably going to cover are: making a logic inverter, a logic controlled load-switch, and reverse battery protection. Simulating in LTspice [circuit CAD], since I can draw that stuff in two seconds and put it on the screen.  If you want to do a power MOSFET application, I would need to see the datasheet for it.  Also keep in mind that high current stuff is no good for breadboards. If you need a list:  4 vs 3 terminal, body diode, Rds(on), gate drive, switching speed, N-channel, P-channel, CMOS digital logic, CMOS analog switches.”

NERP is not exclusively Raspberry Pi, the small computer and embedded systems interest group at Pumping Station:One in Chicago. NERP meets every other Monday at 7pm at Pumping Station:One, 3519 N. Elston Ave. in Chicago. Find NERP and Pumping Station:One at­

Tags: electronics, embedded, NERP, Open Source, raspberry pi, hackerspace, Beagle Bone, Pumping Station One


06 2017

Making stuff for scientific conferences

Last year I was making little things for a conference my work organized in Chicago.

You’ll find more info on my blog posts. But as a teaser, it involved laser-cutting, glue, Inkscape and a lot of mistakes (but I didn’t took pictures of those, too bad).


A person touching a device

Slide Ruler

Circular slide-ruler in acrylic on plywood board.


05 2017

Bronze Casting!!!!!!

As you may have noticed, the Small Metals area has moved to where hot metals used to live. The process has been gradual but successful. We conducted an experiment over the weekend involving plaster investment and molten bronze. There were many variables in this process including new-to-the-space machinery: the kiln, the electric melting furnace, and the vacuum investment table. As well as different materials used, possibly expired flux, a new kind of plaster, and a type of bronze that had been melted a number of times before. All in all it was a great success. Here is a brief overview along with some photos to enjoy.

Seen here is the kiln at a glowing red temperature of 1,500 degrees. The molten bronze getting ready for the pour. Also seen in this picture is the vacuum table for the cast to help pull the metal through the investment.

The Termolyne mini melt electric melting furnace! Bronze has a melting point of 1,742 degrees 

The pour!


Fresh out of the pickle!

Finished rings! All of them (except the black stone in the middle) were cast at PS:One.

-Ella Gentz


05 2017

Turning the Shopbot into a plotter

Former PS:1 president Derek Bever and I were joking in the PS:1 IRC chat room awhile back about using the Shopbot as a tool for uses it was not designed for, and turning it into a plotter seemed especially ridiculous. Since I’d wanted to learn how to use the Clausing lathe, it dawned on me that this ridiculous idea could, in fact, become a terrifying reality. So thanks to Anna Yu who taught me how to use the lathe, I made a bit with an 11mm bore to fit into the 1/2″ collet on the Shoptbot:

Having spent the time to make the part, it seemed silly to stop there, so I realized I’d have to make a post-processor for VCarve and Aspire (Fusion 360 coming soon!). I already had experience with Shopbot’s post-processors, creating a “Always turn spindle off” version of Ryan’s “Always turn spindle on” post processor as well as the XYZ Zero Finder program that works with the XYZ plate made on the Bridgeport. So hunkering down on the computer in the CNC Lounge (where Aspire is installed), I made a “Sharpie Bit” post processor that 1. always turns the spindle off, and 2. always sets Z to 0, regardless of what is done in Aspire or VCarve. This also means you have to explicitly set Z’s 0 position without use of the Z plate as there’s nothing to tell the machine when the ‘bit’ is at the right spot.

The first attempt was made using some cardboard I found in the garbage. This test did not go well because I had set Z to 0 in one corner of the cardboard, but because the cardboard was folded over, it was more puffy in the middle, which means that the Shopbot happily plunged the sharpie into the cardboard. Oops. Try #2 used a piece of acrylic that was laying around and I assumed was garbage, so I used that and the second attempt went much better. Inspired, I grabbed some acrylic from my shelf and made the version below.

I’m going to clean up the code a little (like removing a bunch of debugging stuff, unnecessary pauses, etc.,) and then will run it by Matt (CNC area host) and if he’s cool with it, the bit will go in the drawer and the post processor available to anyone using VCarve and Aspire.


05 2017

NERP Tonite: Replicape rev B!

Tonight at NERP, Elias Bakken of Intelligent Agent AS and Thing-printer, in Oslo, Norway, will tell us about the Replicape rev B. []

“Replicape is a high end 3D-printer electronics package in the form of
a Cape that can be placed on a BeagleBone Black. This page is about
the Major revision B. It has five high power and low noise stepper
motors with cool running MosFets and it has been designed to fit in
small spaces without active cooling and without the need for physical
access to the board once installed. That means no potentiometers to
trim or switches to flip.”

NERP is not exclusively Raspberry Pi, the small computer and embedded systems interest group at Pumping Station:One in Chicago. NERP meets every other Monday at 7pm at Pumping Station:One, 3519 N. Elston Ave. in Chicago. Find NERP and Pumping Station:One at
Doors open at 6:30pm. NERP is free and open to the public. Ed Bennett ed @ kinetics and electronics com Tags: electronics, embedded, NERP, Open Source, raspberry pi, hackerspace, Beagle Bone, Pumping Station One


03 2017

“Digit” Sensors

Knitted Finger Sensor from Jesse Seay on Vimeo.

I machine-knit these finger sleeves from a conductive yarn that changes resistance as the knit is stretched.

With this project, I wanted to design a glove that could be machine-knit for workshops cheaply and quickly, making a wearable bend sensor available to people with no textile skills.

With a range of sleeve sizes, users can select the sleeve with the best fit and resistance range for each digit. We attach flexible silicone wires by means of a snap press, and the wearer then sews the wire in place with a tapestry needle and yarn — very easy!  Once the sleeve is finished, the user can use the tapestry needle to easily sew the wire leads in place along a fingerless glove.

Get your own “digit” sensor at the PS:One workshop on March 25. Details and RSVP on Meetup.  (Workshop fee: $10.)

Jenna Boyles, Kyle Werle, and Christine Shallenberg beta-tested the sensors at Pumping Station: One. They selected sleeves for fit, then stitched on the wires themselves. Kyle and Christine were able to use the sensors to control an analog synth and a processing sketch.

More details here.


03 2017

Coloring Book Adventure

I am making a coloring book.  The way is fraught with fears, doubts, and time eating mechanical failuresFears of being unable to make my goals.  Doubt that my art is worth the investment of strangers.  Battles with an old scanner not being compatible with my computer.  Then a crashed computer bios that corrupted my RAID drive.  I lost a lot of files.  But I am winning.  I am winning thanks to very good friends who encouraged my talents.  I am winning with the support of my very wonderful family that helped me in times of need. I am winning because of my tenacity in the face of problems.  It is only a matter of time in this book battle of attrition.  “Today I Draw Dragons” will be a thing.

I will encourage you too to tread the path of book making.  Be not daunted by the endless tasks before you.

This project began when I started to draw dragons before work and then after work.  I began to count them.  I told myself that when I made thirty five of them I would pursue making them into a coloring book. I ended up making one hundred and fourteen of them.

I shopped around for publishers.  It is a sea of frustration.  You have your easiest ride if you can wrestle the support of a professional publishing company, but they will have a say in your product and it is hard to convince them that you are worth it.  So I decided to pursue self publishing, at least for now.  If I prove myself with a successful project, then I will show them what I can do.

None of this is the way to wealth but it is the way of artists.

Knittin’ Kitten

I learned many things.  I learned that even if I print only 30 dragon images it will be considered a 60 pages plus book to a printer even if I don’t print on both sides of the sheet of paper.  If you have a place to store 1000 books and the cash to buy and ship them then you might be able to get them printed for a competitive price.  ISBN numbers are expensive if you buy just one.

Advertising matters.  My Kickstarter shows a definite lull in support when my computer crashed and I could not reason out how to advertise without my scanned and worked drawings.  My friends and family took up the slack then.  I continued.  I made business cards and flyers to paint the town.  I wish I had done more.  But I am still winning.

Cleaning up and re-working scans for print TWICE is annoying.

I have an external hard drive now so I can back up the back ups.

planned cover image

Learning all the programs for formatting everything for print is a huge pain in my pinky toe.

I still have many tasks ahead.  I need to subscribe to a download service so that I can deliver my PDF. files.  I need to secure a high quality printer for the prints I have sold.  I need to prepare to wrap and mail out my books.  I need to make all the custom sketch cards and commissioned art sold to fund this endeavor.  I will need a plan in place to sell the extra copies I am going to order.  And I need to draw more, lots more.

This will not be my last publishing adventure, by far.

There are still a few more days if you want a copy of the book yourself:

“Today I Draw Dragons” By Shelly Loke

My Kickstarter Ends March 8th, but that is really just barely the beginning.  I hope to see your adventuresome projects up here too, soon.

Dragon Making Toast in the Style of the Ancients



03 2017