Caught in the Shop

I was walking through the shop tonight and saw something awesome happening. I took some crappy photos to show you (and I’m not sorry about it!).

That's a big piece of metal

Our Cold Metals area host, Mike, holding a big piece of metal. He’s going to turn it into a smaller piece of metal.

DSC_5730

Mike and Dean work on centering the piece.

DSC_5723

This is the part they’re trying to reproduce. This is a pulley for our new(ish) Johnson horizontal band saw. You’ll note that it’s bent. It’s also incorrectly sized, so there’s a bushing that’s been inserted that you can’t see. This bushing has no key, so the pulley was fairly noisy and inefficient.

 

 

25

03 2014

NERP: Playing with the BeagleBone Black

NERP is not exclusively Raspberry Pi, the small computer 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.

Tonight at NERP, we’ll be playing with the BeagleBone Black. We’ll compare the look and feel of an original Angstrom Linux install with a fresh Debian Wheesy install. Beagles and their kin are complicated little devices, and there’s lots to see and try out (and fix) for a newbie user. We’ll sniff around the Beagle install and hardware just to pick up some landmarks for future projects and ideas.

 

Find NERP and Pumping Station:One
at http://www.meetup.com/NERP-Not-Exclusively-Raspberry-Pi/
and http://pumpingstationone.org/
Doors open at 6:30pm. The next meeting is March 17th, 2014. 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, Element14, Pumping Station One

 

17

03 2014

Adding digital speed indication to a drill press.

There’s a big bin of 5 digit, 7-segment displays sitting in our electronics lab. It’s the sort of thing that cries out for a project. I found one that’s the perfect shape for a digital speed readout for our big drill press, whose mechanical RPM indicator was broken.

2014-02-16 18.26.53

Testing out the display PCB. It’s got 3 16 bit shift registers.

The display was pretty simple to reverse-engineer. There’s a header on the back that’s connected directly to the relevant pins on the first shift register. Apply power, fire up a basic sketch built around shiftOut(), and away we go.

2014-03-10 21.16.13

My test rig, showing that the RPMs pretty close.

My code (patches welcome!) is not terribly complex. Basically I use a Hall effect sensor to trigger an interrupt every time a magnet glued to a wheel in the drill press passes. The time between interrupts is used to calculate RPM.

2014-03-13 21.25.16

Magnet + Hall effect sensor.

All told, I spent maybe four or five hours on this project. It’s probably the simplest possible solution to the problem, and my total investment is less than $10 in parts. And we’ve got an accurate readout of the speed of this big drill press.

2014-03-13 18.49.28

Complete system.

I’m out

-loans

13

03 2014

NERP: At Last — A JavaScript MCU!

NERP: At Last — A JavaScript MCU!

NERP is not exclusively Raspberry Pi, the small computer 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.

It was time, perhaps past time for a JavaSscript microcontroller to appear. Tonight Drew Fustini will show us a high-level overview of the Espruino. The Espruino controller board is just emerging from Kickstarter and can be ordered through one of their distributors. http://www.espruino.com/
Lots of people know JavaScript and its programming environment, and many of those people could be convinced to try their hand at using a microcontroller if they could use their preferred programming language – in a Web IDE. This is important stuff, but the really striking thing is that event-driven processes are now in easy reach of people who need the capability but don’t want to learn a real time operating system. A very common question people in their first hour of Arduino programming will ask is “Now how do I blink two LED’s?”. Having spent a lot of time teaching Arduino 101, I can say that it’s always an awkward moment when you say “Well, you can, but it’s really involved”. JavaScript combined with a bit of Arduino vernacular solves the problem in a way that might be expected in an event-driven system. It’s wonderfully short and simple. Snagged and slightly edited from the espruio.com site:

function toggle1() {
on1 = !on1;
digitalWrite(LED1, on1);
}

function toggle2() {
on2 = !on2;
digitalWrite(LED2, on2);
}

setInterval(toggle1, 400);
setInterval(toggle2, 456);

Each time you called setInterval(), it returned a different number. If you want to change how fast the interval runs (or cancel it altogether) you need to use this number:
changeInterval(1,1000);
or
clearInterval(1);
[end quote]

Almost predictably the CPU is an ARM M-series like so many other of the 32-bit MCU convenience platforms. For instance an M3 type is used in the Espruino and an M4 type is used in the Teensy 3.1. It is unclear to me whether portability of code will carry across different chip makers, but the M3 vs M4 difference per se may not matter. From Element14's community site:

...most features of the Cortex-M3 and M4 are the same with the significant difference that Cortex-M4 has DSP extensions and an optional FPU. There is nearly no need for modification of hardware and software to migrate from M3 to M4. [http://www.element14.com/community/docs/DOC-36208/l/migrating-from-cortex-m3-to-cortex-m4-by-element14 ]


Like the relationship between the Arduino and the ATMega MCU’s from Atmel, there is an Espruino board and Espruino libraries. Also similarly, the libraries are open source and theoretically portable to other boards using the same or similar chip. Some possibilities labeled as “unsupported” are listed on the Espruino site.
Will it become common to pick your ARM board and then pick your development system?

–----------

Also tonight, Ed will talk about some of the issues in making a clock that uses a funky, antique digital display called a “one-plane readout”.

Find NERP and Pumping Station:One
at http://www.meetup.com/NERP-Not-Exclusively-Raspberry-Pi/
and http://pumpingstationone.org/
Doors open at 6:30pm. The next meeting is March 3rd, 2014. 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, Element14, Pumping Station One

03

03 2014

Bike Night – Fixing bikes in February

Hello everyone!  It’s been cold.  It’s been snowy.  But some of you people are still riding your bicycles.  Being cold and snowy doesn’t stop the need for maintenance.  Every other week is Bike Night at PS:1, and we’ve got our doors open for you.

Sometimes we bring in things to show off.  Sometimes we teach.  Usually we work on interesting bike projects.  (Learning how to wrap bars, building a bike from the frame up, etc) Last night was playing bike doctor more than “here’s fun stuff to work on.”  We had two patients last night.

Bike maintenance at PumpingStation

Bike maintenance at PumpingStation: One

 

 

 

 

 

 

 

Patient #1 received a new chain and sprockets to replace a stretched set.  And, the rider discovered the magic of clipless pedals last year, so replaced his platforms with some SPD pedals.

Patient #2 had some cheesy short term replacement pedals replaced with some very nice platforms, and had it’s headset rebuilt.

Does your bike need a tuneup?  Do you have questions about picking a new bike this spring?  Do you want to learn a new bicycle related skill?  Come visit us, we’ll be gathering in the shop March 5 at 7PM.

-Nerobro

20

02 2014

NERP: Spark Core – Warm and Fuzzy Computing

Monday Feb 17th at 7pm Jeff Camealy will present his talk “How to control your electric blanket with a Spark Core”. He describes his use case: “The Spark Core is a small Arduino compatible chip with built in WiFi and Cloud connectivity. This functionally can be used to easily create a device that can be controlled remotely. We’ll see how we can use the Spark Core Cloud to create an iPhone App to direct your blanket from the comfort of your .. blanket.”

nerp_spark-core-2

Lest Jeff sell himself short, it should be said that he’s spotted a technology that’s powerful and significant, but also somewhat strange. Until now the Arduino programming environment hasn’t often been associated with cloud computing. It’s not clear to me whether this is a niche application, or the start of a trend in small embedded controllers. Not surprisingly, the ARM architecture continues to insinuate itself into every corner of embedded control. The Spark Core uses an STMicroelectronics STM32F103 ARM M3 running at 72 MHz. The WiFi is provided by a TI SimpleLink CC3000 module. If you don’t like the cloud you can use the Spark Core as an ordinary USB-programmed controller that has WiFi. The spark.io site contains these [edited] points to help in understanding what the Spark Core does:

The Spark Core is a tiny, open source Wi-Fi development board that makes it easy to create Internet connected hardware. The Core is all you need to get started; power it over USB and in minutes you’ll be controlling LEDs, switches and motors and collecting data from sensors over the Internet!

There’s no need to ever plug the Core into your computer; you can write code in our web IDE and download it wirelessly to the Core. The Core uses Wiring, the same programming language that Arduino uses. Plus, with an accessory called the Shield Shield, you can connect the Core to a standard Arduino shield.

The Cloud is the mother ship that the Spark Core connects to when it comes online. Once the Core is paired with the Cloud, it becomes accessible from anywhere in the world through our open but secure REST API. Cloud service comes free for life with the Core. [excerpts from https://www.spark.io/]

Excitement!

Thanks to Drew Fustini and the kind folks at element14, we’ll have a drawing for a fully assembled Gertboard. “Gertboard is the ideal add-on for Raspberry Pi. Designed by Gert van Loo, it is a flexible experimenter board that plugs directly into your Raspberry Pi, and out into the physical world…” [element14]

NERP is not exclusively raspberry pi, the small computer interest group at Pumping Station:One in Chicago. Find NERP and Pumping Station:One
at http://www.meetup.com/NERP-Not-Exclusively-Raspberry-Pi/
and http://pumpingstationone.org/

NERP meets every other Monday at 7pm at Pumping Station:One, 3519 N. Elston Ave. in Chicago. Doors open at 6:30pm. The next meeting is Feb 17th, 2014. 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, Element14,
Pumping Station One

14

02 2014

NERP: Teensy 3.X – a 32-bit ARM microcontroller board for <20$

The Teensy name has been around for several years in the land of 8-bit MCU boards, but the 32-bit Arm platform introduced in Teensy v3.0, is a game-changer. PJRC (http://pjrc.com/teensy/teensy31.html)sent a few Teensy 3.0′s to Anna (our Electronics area host) at PS:1 with no discussion or fanfare. Thank-you, PJRC.

AT NERP TONIGHT, Ed will show the Teensy 3.0 hardware, Arduino tools, and some sample programs. After that introduction to the Teensy 3.0, Colorado Rob will show how he programs the Teensy 3.1 with a combination of tools and utilities from Eclipse, GNU, Freescale (manufacturers of the Teensy ARM MCU), and freeRTOS. ALSO – We’ll also raffle a new in box original aka white BeagleBone. Thanks to Drew for the donation!

The Teensy 3.X’s cost less than $20 and include all the peripherals you expect in a regular MCU. Some specs on the Teensy 3.1 are:

MCU MK20DX256VLH7 Cortex-M4, 72Mhz (96MHz overclocked), 256k flash, 64k RAM, 2k EEPROM, 34 dio pins, 21 analog input pins, etc.

The Teensy 3.0 is (mostly) pin compatible with the 3.1. The v3.0 uses an MK20DX128VLH5 MCU with 34 dio pins, 14 analog input pins, etc. Other spec values are one-half or less of the ‘DX256VLH7.

The 32-bit ARM chips are internally much more complicated than 8-bit processors, but the user doesn’t have to be aware of this when programming them. The Teensyduino IDE from PJRC provides a familiar user interface and Arduino(TM) libraries that make getting from zero to blinky very easy. There are additional libraries that provide access to some of the ARM-specific resources such as the USB port.

I’ve been exploring the v3.0 samples and am pleased with their sale price and performance. My setup is the basic Arduino install + Teensyduino on Linux. After doing the Arduino install I played with some sample code that does HID mouse and keyboard emulation on USB. Making it work was pretty straightforward.

Colorodo Rob writes:

I have been playing around with the Teensy 3.1 for a few days. It’s an ARM board for $17.
http://store.oshpark.com/products/teensy-3-1

My thoughts on it so far are that the CPU is way overkill for most embedded things that you’d program with the Arduino programming environment and library.* Also, there is a huge increase in complexity to overcome to program if using “real tools”. But the Arduino tools are easy to set up and use. But for my embedded project, the Freescale CPU it uses has the potential to save a bit of money. Even though the CPU costs more than the AVR part I currently use, it includes a USB controller and a voltage regulator, so those component costs go away. I’ve been following a tutorial for setting up a dev tool chain for these CPUs using Eclipse, GCC and Freescale’s tools:

http://mcuoneclipse.com/2013/07/20/dyi-free-toolchain-for-kinetis-part-1-gnu-arm-build-tools/

I’m looking at FreeRTOS (modified GPL) now. I’ve just gotten the ADC working with DMA which is pretty cool. My completion handler gets called when there are 32 samples ready for me, which is what I need for the carrier detect algorithm. The Freescale tools are pretty powerful for what they allow you to do, and an RTOS provides interesting departure from the sequential programming typical of Arduino development.

*Rob and I differ on this point…

NERP is not exclusively raspberry pi, the small computer interest group at Pumping Station:One in Chicago.

Find NERP and Pumping Station:One
at http://www.meetup.com/NERP-Not-Exclusively-Raspberry-Pi/
and http://pumpingstationone.org/

NERP meets every other Monday at 7pm at Pumping Station:One, 3519 N. Elston Ave. in Chicago.Doors open at 6:30pm.The next meeting is Feb 3rd, 2014. 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, Element14,
Pumping Station One

03

02 2014

CNC Steampunk Harp – The Sector67 Field Trip – Part 2

 

Finished Sound Board

Finished Sound Board

[See Part 1]

The sound board of the harp had always been the wild card. Elizabeth and I began the project last year knowing that we’d want to use a laser cutter to etch it with some kind of Victorianesque steampunk design involving gears. And we knew that PS:One’s Epilog, with its 24″ x 12″ bed and no feedthrough capability, simply couldn’t fit a 49″ sound board. While design focused on the brass panels, as we did have access to a CNC router, the sound board was left for later, especially because we didn’t know if we could find a smaller laser cutter with feedthrough, meaning we needed a design that could be etched in pieces, or a large laser cutter that could engrave the entire sound board at once.

Elizabeth and I were planning a trip to Madison, WI, and we heard rumors that Sector67 had a colossal Chinese import laser cutter. I reached out to them asking if they would be willing to help with this project, and Chris Meyer, director of Sector 67, responded, inviting us to their space. Knowing what we had to work with, Elizabeth was able to create the design in Adobe Illustrator. Read the rest of this entry →

01

02 2014

CNC Steampunk Harp – Part 1

 

Side view of harp with pockets routed

Side view of harp with pockets routed

For the past year, Elizabeth and I have been collaborating on a project using the amazingly cool CNC tools at Pumping Station: One. The goal: to build a harp. Not just any harp, mind you. A steampunk harp! The idea was to start with a kit (the Voyageur harp from Music Makers, 33 strings, cherry) but heavily customize it as follows:

  •  CNC cut brass panel inserts, inlaid in pockets routed in the sides of the harp
  • The brass panels would be etched using a galvanic etching process, similar to the one used by the Steampunk Workshop to create their clockwork guitar. Elizabeth would design the shape and custom artwork (gears, of course!) for this.
  • The sound board would be laser engraved with some type of steampunk design. The design is in progress, and we are searching for a laser engraver large enough to handle the sound board.
  • Although not strictly steampunk, I’d considered adding RGB addressable LED lighting under the neck of the harp, which could illuminate the strings, as well as respond to the pitch of the strings being played.
CNC routing brass

CNC routing brass

First, we had to start by routing the brass, using PS:One’s CNC 3020 router. Elizabeth drew the design, including the brass outline and the pattern we will use when we etch the brass. We did this last spring at PS:One, and we ran into massive problems with the brass vibrating and breaking end mills. The project remained dormant for many months until a breakthrough: What if we glued the brass to a scrap board? That would at least keep it immobile so it couldn’t chatter and bind on the end mill. The good news: This worked! Success! The bad news…. The Go To Home button on Mach3 does not, by default, raise the spindle before moving it. And a clamp was in the way. The result: A badly bent spindle. Well, all was not lost….
Read the rest of this entry →

23

01 2014

New Year, New Beer, Beer Church is Here

Don’t let the polar vortex’s return prevent you from standing around a boiling cauldron of delicious smelling beer wort as we prepare to create what’s bound to be a unique beer. We usually base our recipes on existing ones, but tweak them in interesting ways.

To start off, we’ll have a beer tasting featuring any homebrew you bring, a Gingerbread Brown Ale that we brewed in December, and the aged return of 14 month old “I Didn’t Mead It That Way”, a session mead made with hops and fermented with wine yeast for a very unique and floral flavor. Tiny beer steins will be provided – please bring a bottle of something if you can. We might even pull some mystery bottles from our homebrew cellar and see if we can remember what it is!

Once we’ve had a taste, met each other, and talked over the basics of brewing in the process, we’ll move on to shopping for ingredients (Brew & Grow is right around the corner, and you’ll get to learn how to weigh and grind ingredients) & of course brewing the beer. This is just the first day of a weeks long journey that a beer takes from the boil kettle to your mouth, but it’s the most labor intensive and the most interesting to see, so we like to show people this step. Watching a bucket ferment isn’t as fun. Since we’re going for something relatively straightforward (recipe to be a surprise), we’ll probably be done brewing in around 3.5 hours. We’ll get into the brew by around 3PM. The steps include mashing, sparging, boiling, chilling, and pitching. You can lend a hand with most of them if you like, and learn a lot in the process.

mmmm, beer

Nitty Gritty

When: Sunday January 19th 2014, 1PM
Where: Pumping Station: One, 3519 N Elston, Chicago
What: Beer tasting and brewing hands-on
Who: Anyone 21 or over, Pumping Station: One members or not!
Why: Because beer is a fun way to spend for your Sunday afternoon

18

01 2014