Giveaway: LeoStick winners

Today we announce the winners of the LeoStick contest. Freetronics’ new LeoStick is an Arduino Leonardo compatible USB board. It’s a simple breakout for the ATmega32U4 microcontroller in small USB stick shape. It has 2 RGB LEDs and a buzzer on-board for experimenting.

There were lots of great ideas for projects based on the LeoStick, thanks for your submissions.

Congratulations to Fractal, his Bike light “contrologger” idea scored him a LeoStick:

It’s a pretty small device, and fairly low power too. I’d put on a LCD, eeprom, accelerometer, battery, and hall effect sensor(or reed switch) and mount it on a bike.
Bike light contrologger. (totally should be a word)
Can show your relative speed on the RBG LED ‘at a glance’. It could also drive bright side blinkers, to make turn signals clear to other traffic, controlled by a thumb switch. The accelerometer would also detect braking (or a microswitch), and flick on a brighter brake light. When done, simply plug into your computer to upload that day’s stats. If you’re feeling fancy, a GPS could even log your daily route, and ADCs could measure pots on the brake levers and gear controllers. Box would be pretty small, really, and plug in via a locking plug to prevent falling out. End result- pretty graphs.

Cubeberg’s music controlled fireworks wins a LeoStick:

PC Controlled fireworks display! A little programming and you could sync it to music!

Another winner is Pesse’s drink making machine:

I´m trying to build a drink making machine with some friends, right now we are trying some methods for dispensing the liqueds, but this would be perfect for the brain part of the project…

Yancheelo scores the last license for a LeoStick:

LeoStick would be perfect to implement a very simple project that I have in mind: controlling the scrolling of the current active window with a simple movement of the hand. A proximity sensor is connected to LeoStick which will scroll down the page if the hand is moving towards the sensor, or scroll up if the hand is moving away from the sensor.

We would love to know what becomes of these projects so please share them with us in the forum or via the contact form.

Thanks to Freetronics for supplying the free swag.

Thank you for participating, there were a bunch of great ideas.

512K SRAM memory module with 13 pin interface

An open source 512K SRAM memory module for adding extra ram to your project:

I have designed a very simple PCB module that allows access to 512KBytes of Static RAM.  It is compatible with any microcontroller with at least 13 free digital IO pins and the ability to run from a 3.3v or 5v supply.

It uses four 128K x 8bit SRAM chips connected in parallel. This is a 4 layer board with components placed on both sides.

Kicad libgen tool


Boseji informs us of the new libgen tool for creating Kicad schematics symbols.

This tool is based on Python and can generate one Component from a XML file.This tool in multiple ways emulates the Quick KICAD Library Component Builder online tool for generating the symbols. However since it’s standalone it becomes easier to edit and customize. Another important feature is the XML based component generation. This makes it easy to customize the pins in text rather than selecting again and again. All the Pins can be Named using the XML file and there EType as per the Kicad norms can also be set.

The project is open for suggestions and contributions.

Visit AdharLabs Github page for more information and downloads.

Via the contact form.

Lil Bang – Sound trigger for cameras

Viktor made a sound trigger for his DSLR camera:

Now that I can take pictures of lightning I decided that I also want to be able to trigger my camera with sound.

An op-amp filters and amplifies a microphone signal. The output is fed to a PIC microcontroller that triggers the flash when the sound reaches a certain level. The trigger sound level and shutter delay are set with a pot.

WORKSHOP VIDEO #08: How to mail free PCBs

This week we talk about the Free PCB drawer, and show how we mail out all those free PCBs.

We order PCBs from Seeed Studio’s Fusion PCB service and get ten copies of every board. Usually we only need 2 or 3, so that’s a whole lot of PCBs we’ll never use.

Since the beginning, Dangerous Prototypes has given away the extras. In the beginning it was a specific board given away on blog post every Sunday, originally conceived as a totally lazy, no effort Sunday afternoon filler post.

After a while it occurred to us that the PCBs might be more useful if people could get one they want. We took inventory of the extra PCBs stored in a desk drawer and entered them into a Zencart based store we call the Free PCB Drawer. Instead of giving away a specific PCB, we started giving away codes to pick a PCB from the store. This has the side benefit of automatically formatting addresses correctly.

Providing a choice of PCBs turned out to be a winner. A lot more boards are built up and tested. To encourage users to post their builds, we started the ‘unlimited free PCB program’. Users who post pictures of their build on a blog, flicker, or in the forum get another PCB code. There’s a whole community of regular builders now who sometimes even test a project before we do.

Every week we give away 6 PCBs in contests, a few to repeat builders, and sometimes more to people who ask nicely or do something awesome. We’ve averaging 45-50 per month, over 400 orders have shipped from the free PCB drawer so far.

If you’d like to win a free PCB, we give out 2 every Friday over Facebook, 2 every Sunday here on the blog, and 2 every Tuesday on Tweeter.

All our videos.

28C3: SCADA and PLC vulnerabilities in correctional facilities


In this full length presentation from the recent 28C3 conference in Berlin, Tiffany Rad, Teague Newman and John Strauchs describe the opportunities and challenges presented by SCADA systems used in prisons and jails.

These systems are often used in conjunction with PLCs to open and close doors. Using original and publicly available exploits along with evaluating vulnerabilities in electronic and physical security designs, Newman, Rad and Strauchs have discovered significant vulnerabilities in PLCs used in correctional facilities by being able to remotely flip the switches to “open” or “locked closed” on cell doors and gates. This talk will evaluate and demo SCADA systems and PLC vulnerabilities in correctional and government secured facilities while recommending solutions.

UPDATE: According to the speakers, John Strauchs and his company were the inspiration for the 1990s hacker flick “Sneakers”. However, this is questionable (see comment below).

HOW-TO: Get your PCBs manufactured

The latest version of this tutorial is available on the documentation wiki.

In the last few years many inexpensive PCB services have popped up. It used to be that buying PCBs in hobby quantities was expensive and filled with gotchas.

Now, places like Seeed Studio can send your PCBs to the inexpensive prototyping factory in Shenzhen China, and ship them anywhere in the world at great prices. You get two-sided PCBs, with the works, starting at $1 per 5x5cm PCB. Turnaround is a few days, worldwide shipping starts at $3. It’s a happy day for electronics hobbyists.

Other services like DorkBotPDX and BatchPCB pool multiple orders so the group benefits from bulk pricing. Enough people are using these services that turnaround is quite fast. DorkBotPDX offers signature purple PCBs that have become quite popular.

Our goal is to help you get your Eagle PCB designs manufactured. We show our ‘pre-flight’ checks to help spot problems before ordering boards. Learn what defects to spot, like under etching, over etching, and misaligned vias. How-to continues below the fold.

Continue reading “HOW-TO: Get your PCBs manufactured”

Free PCBs for pictures of PCB errors

We’re writing a new tutorial on PCB manufacturing, and we’d like to add pictures of common PCB manufacturing errors. We’ll give out free PCB coupons in exchange for open source licensed images (limit 4).

Here’s the examples we need, the first two are the most important right now:

  • via alignment problem (drill not centered in via copper)
  • missing traces (over etching)
  • shorts (under etching, as shown above)

Image by Sebastian: CC BY-SA

A culture of ethics in open source hardware?

Phillip Torrone of Adafruit and Make wrote a piece on the culture of ethics in open source hardware:

I spend most of my days working on open source hardware in some way, and I wanted to talk about some of the {unspoken} rules we all, well, many, seem to follow. Why? Because the core group of people who’ve been doing what we’ve collectively called “open source hardware” know each other — we’re friends, we overlap and compete in some ways, but we all work towards a common goal: sharing our work to make the world a better place and to stand on each others shoulders and not each others toes : )

He makes 11 points. We added some comments to our favorites below the fold. What do you think?
Continue reading “A culture of ethics in open source hardware?”

Testing the photovoltaic effect with a transistor

When you expose the silicon die of a transistor to a light source a charge is produced. CircuitsDIY opened up a 2n3055 transistor and did some experimenting. With the help of a magnifying glass he was able to built up a charge of 0.65V and produce 42.2mA of current.

Most photovoltaic cells are made of silicon chip above which there resides a very thin layer of noble metal through which around 1% of photon particles enter the material and activates electron flow.

Here I’m showing how to make one simple solar panel using transistor.

Builld a touch activated Valentine’s LED card

Happy Valentine’s from Dangerous Prototypes. This touch activated Valentine’s card is one of Ian’s early projects at DIY Life.

It’s designed to be home-etched on a single-sided PCB. A PIC16F microcontroller fades the LEDs like a heart beat. It’s activated when someone touches the conductive pad, which allows current through a PNP transistor and wakes the PIC from sleep.

MakiBox A6 $300 Desktop 3D Printer


Drone writes about a new 3d printer project he’s found:

MakiBox A6 is a new crowd-funded project by Jon Buford in Honk Kong. Price is $300USD each plus $50USD International shipping. The basic kit includes all MakiBox parts with electronics and power supply and 1 kg of plastic (2 x 1/2kg spools of ABS). No software is included but there are plenty of open-source solutions. For example, ReplicatorG (http://replicat.org/) is mentioned as the STL file gateway feeding MakiBox.

The MakiBox uses trapezoidal drive shafts that provide 8mm/revolution travel. Print speed should be around 60-80mm/sec. with 1.8 deg. steppers. There is a heated printbed. The consumable material is typically 1mm ABS plastic which MakiBot will sell for $20USD/kg in 1/2kg spools (which is pretty cheap by today’s standards).

Go to Makibox for more details and videos on the project’s development.
Via the contact form.

#FreePCB via Twitter to 2 random RTs

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters.

Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

Giveaway: 4 LeoStick Arduino Leonardo compatible USB sticks

Freetronics’ new LeoStick is an Arduino Leonardo compatible USB board. It’s a simple breakout for the ATmega32U4 microcontroller in small USB stick shape. It has 2 RGB LEDs and a buzzer on-board for experimenting.

The LeoStick is just like the upcoming Arduino Leonardo, but given the “honey, I shrunk the kids” treatment! Just pop it into your USB port (no cable required!) and upload straight from the Arduino IDE.

We are giving away 4 LeoSticks! Leave a comment on this post with an idea for a LeoStick project, and one of the boards could be yours on Thursday.

Free PCB Sunday statistics – when will you get one?

A happy winner of this Sunday’s Free PCB giveaway suggests there is a 50% chance of winning a PCB after 25 weeks:

Thanks a lot! Just for the statistics: it took 13 drawings to get this code, which is way below average (there seem to be, on average, 110 comments on each sunday, which means it takes 25 weeks for a 50% chance :)

You can improve those chances by participating in Free PCB Tuesday on Twitter, and Free PCB Friday on Facebook.

Once you get a PCB, just build it and post a picture to get another free PCB code. It’s like unlimited free PCBs.

Via the contact form.

Large plot data warning from Cadsoft Eagle CAM processor

Today we got a new warning from Eagle’s CAM processor when exporting gerbers to make PCBs. When the CAM processor started we got the error “Board contains a polygon that may cause extremely large plot data”. After some removing nearly every component from the PCB, we found that it was related to the arrows on the silk shown above. The edges have a sharp angle, and the polygons at the tips have a width of zero. To correct the issue we changed the offending polygons’ width to positive value.

Years project uses Arduino to play tree rings

YEARS from Bartholomäus Traubeck on Vimeo.

Bartholomaus Traubeck presents his “Years” project. Years is a phonograph-like device which reads the characteristics of the rings in a thin cross-section slice of a tree and interprets these as piano notes depending on the appearance of the wood (ranging from dark to light and from strong texture to light texture).

No source or schematic available.

DIY rosin solder flux made with isopropyl alcohol

Arhi tried his hand making DIY rosin-based solder flux. He added crushed rosin to isopropyl alcohol until it had the desired viscosity.

The video is a test of the new flux on 1 mm and 0.5 mm pitch components. By his account it works better then some commercial products, but there’s also more smoke and residue.

Via the forum.