Free PCB coupon to RT #5 & #16 @dangerousproto

Every Tuesday we give away some extra PCBs via Twitter. This post was announced on twitter. The 5th and 16th person who retweet it get free PCBs. We changed the approach this week due to auto-retweeters grabbing boards first. Thanks for the heads-up on auto-retweeters JT! Love it, hate it? Let us know in the comments below

This week we’re giving away two PCB codes. Pick your own PCB from the free PCB drawer.

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

  • Free PCB Sunday. The classic. Every week, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs while you wait for the weekend

You can get the Logic Shrimp for $34.90 at Seeed Studio.

Continue reading “Free PCB coupon to RT #5 & #16 @dangerousproto”

Arduino realtime audio processing


Lab3, the Laboratory for Experimental Computer Science at the Academy of Media Arts Cologne, posted this tutorial on how to perform realtime audio processing with an Arduino. They explain:

This is an experiment to show how some realtime audio processing can be done with the Arduino. The first set of examples alter an incoming audio signal and put it back to an audio output. We achieve effects like Reverb, Phasor, Flanger or Ringmodulator. The second set of examples are outputting computed waveforms like Sinewave, Bell and Xylophone sounds.

Full source code and circuit diagram are included.

Arduino Ethernet + SD card tutorial


Ladyada has posted this detailed tutorial over at Adafruit on using Ethernet and SD card with Arduino. It describes how to use the Arduino to browse files on an SD card remotely. This tutorial is targeted at those who already have quite a bit of Arduino or microcontroller experience and are ‘fluent’ in C/C++/Java!

Server hosting Adafruit style

Adafruit took pity on us and shared some valuable web hosting experience:

After hearing about Dangerous Prototype’s search&move to a new hosting provider, we thought we’d post up about our hosting experiences! We currently use ServInt for our hosting provider. They’re what we would classify as a ‘full service’ provider. Basically they own the computer, the pipe and do all the management including backups. We get root shell access and install whatever we’d like. When we have any problems (including stuff like upgrading software or installing something) we open up a ticket.

We push over a terabyte a month, running our shop, hosting files, videos and tutorials and its been pretty much flawless. We started with the low cost VPS service and did that for a few years, now we have a dedicated server and its managed to live through many ‘slashdottings’ with no problems. We’re still wary of ‘cloud’ services – our needs are pretty consistant so we’d rather have a single server that can provide for our needs. If our traffic increases dramatically we may move to a cloud service for image or video caching, we’ve done that before when were were on a constrained provider and that helped us keep transfer costs down.

Great advice. We also swore never to get involved in the DIY server game, but ended up there anyways. More one why this happened, and the current state of the site, tomorrow.

Amateur radio study guide has much information about electronics

Ham radio is nothing new, however if your new to electronics, or interested  in becoming a ham, we suggest reading one of Dan’s self-study guides.

The RMS value of an AC signal is the voltage that causes the same power dissipation as
a DC voltage of the same value. (G5B07) For an AC signal with a sine-wave shape, the
RMS value is .707 times the peak value. 12 volts is the RMS voltage of a sine wave with
a value of 17 volts peak. (G5B09)

Conversely, the peak-to-peak value of an AC signal is 2 × 1.414 × the RMS value.
Accordingly, 339.4 volts is the peak-to-peak voltage of a sine wave that has an RMS
voltage of 120 volts. (G5B08)

Power is equal to the RMS voltage times the current, or
P (watts) = VRMS x I

Using Ohm’s Law, we can show that:
P = V2RMS / R
P = I2 x R

The amateur radio exams require you to understand subjects like ohms law, reactance, inductance, impedance, and capacitance, along with many other electronics principles. His study guides are not your average list of the question pool, it has been rearranged in a manner that presents you with explanations and examples and references to the question to witch it applies. About 70 pages long(pdf) this is an excellent way to study for your technician class, or upgrade to your general class, or even just learn something about eletronics.

There are versions available for the Nook and Kindle at a reasonable price, or a free PDF.

via the contact form.

Lattice launches “Do-It-All PLD” design challenge


Lattice Semiconductor Corporation and UBM Electronics have announced the Lattice “Do-it-All PLD” Design Challenge. The objective of the Design Challenge is to foster a social community in which electronics engineering contestants can use the Lattice MachXO2™ Pico Development Kit to create designs for evaluation by a panel of expert judges.

The Design Challenge will take place in three phases: Conceptual Design, Design, and Voting. Judges will choose up to 15 semifinalists in phase one and then up to five finalists in phase two. Each semifinalist will receive a free Pico Development Kit, a $49 value. Social community members will then vote for the Grand Prize Winner, who will be awarded $3,000. Each registered community member who participates in the Voting phase will be eligible to win at random one of ten $100 prizes.

The first phase entry deadline is July 18, 2011 at 8 a.m. EDT. Visit the Lattice PLD Challenge website for rules and registration information.

Bent Festival 2011

If you’re into circuit bending you may want to check out Bent Festival 2011. Bent is an annual art and music festival celebrating circuit bending and its related creative practices: DIY electronics, hardware hacking, glitch, code bending, software art, abstract video. Now in its 8th year, the festival will be held June 23-25, 2011 @ 319 Scholes, Brooklyn, NY.

Checkout the Bent Fest website for a schedule of events and to purchase tickets.

Logic Sniffer case: what is it?

Ed was going through his drawers and accidentally found a great Open Logic Sniffer case.

Can you tell what this case was originally designed for?  The first person to guess gets a free PCB code. There’s another picture below the break.

Via the contact form.

Get a Logic Sniffer for $50, with free worldwide shipping.

Continue reading “Logic Sniffer case: what is it?”

The backcountry logger

Big Mess o’ Wires backcountry logger:

If you’re just tuning in, the backcountry logger concept is a portable ATmega-powered device that collects temperature, air pressure, and altitude data, and shows graphs on a built-in LCD screen. It’s intended for hikers, climbers, and other outdoorsy folks who want to know if it was colder last night than three nights ago, whether the ridge they’re on is the 10200′ or 10600′ one from the map, or whether a storm is likely soon. Much attention has been giving to minimizing power consumption, so the battery should last many months.

Another OverLoad review

Another review of ITead’s OverLoad programmable dummy load:

All in all, interesting device. The only major flaw I see attm is that instead of using DAC and drive the current value trough mcu they are doing that analogue … I’ll check schematic to see if there is DAC on board at all, but if not I see that there is i2c on the connector, maybe it would be an easy hack to add DAC there and link instead of the pot .. I haven’t used i2c dac’s mostly spi but I assume there are some nice i2c versions too :)

Thanks arhi. Via the forum.

Looking up at the spy


When spy satellites peer down at you from over head, what can you do? Well, if your’re Thierry Legault and Emmanuel Rietsch you look back! The pair of enterprising Frenchmen have modified a consumer-grade telescope, added a small motor, hand-held controller and a video camera. The result is a do-it-yourself satellite tracker capable of recording the movements of America’s most secretive spacecraft.

You can check out some of their photo trophies at Thierry’s website.

Via Wired.

Free PCB Sunday: Pick your PCB

We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service.

This week we’re giving away two coupon codes for the fee PCB drawer. Pick your own PCB. Remember you get unlimited free PCBs now – finish one and we’ll send you another!

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

  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs while you wait for the weekend

You can get IR Toy v2 for $22.05, including world wide shipping.
Continue reading “Free PCB Sunday: Pick your PCB”

Epson S4E5A0A0 Inertial Measurement Unit

At recent international trade shows Epson debuted the S4E5A0A0 Inertial Measurement Unit (IMU). An inertial measurement unit senses inertial motion consisting of angular rate sensors on three axes and accelerometers in three directions. IMUs are primarily used to measure and control the behavior of mobile objects.

The IMU includes triple gyroscopes and a tri-axis accelerometer, for six degrees of freedom. The gyroscope provides high accuracy and stability (±300 deg/s), while the accelerometer offers a dynamic range of ±3 G. It offers excellent angular rate measurement performance (angle random walk: 0.24deg/√hr) and stability (gyro bias instability: 6 deg/h). The device is also equipped with industry-standard SPI and UART interfaces.

This Epson component is suited to industrial applications in areas such as inertial motion analysis and control, motional analysis and control, moving object control, vibration control and stabilization, and navigation systems.

Now, the bad news. At $2,500 per chip, the S4E5A0A0 is targeted toward industrial applications. It will reportedly begin shipping in July.

App note: Overvoltage protection for amplifier outputs

rsdio writes:   this circuit includes one of my favorites: a dual, common-cathode diode package

To protect audio amplifiers and other automotive electronic circuits in the event of an accidental direct connection to the car battery voltage, add the circuitry shown (a shunt regulator, diodes, and an n-channel MOSFET in series with each audio path).

Designing and building a bench supply

Another article that might help with bench power supply designs:

A good, reliable and easy to use bench power supply unit is probably the most important and most used device in every electronic lab. A proper electronically stabilized bench power supply unit can easily cost over 200 Euro.  Using a clever microcontroller based design we can build a power supply which has more features, is easy to build and and even cheaper.

Via Hack a Day.

EKOPath 4 Compiler Suite going open source

PathScale has announced that the EKOPath 4 Compiler Suite is now available as an open source project and free download for Linux (RedHat Enterprise Linux 5 and 6, SUSE Linux Enterprise Server 10 and 11, and Ubuntu 10), FreeBSD and Solaris. According to the press release:

This release includes documentation and the complete development stack, including compiler, debugger, assembler, runtimes and standard libraries. EKOPath is the product of years of ongoing development, representing one of the industries highest performance Intel 64 and AMD C, C++ and Fortran compilers.

The free download can be found here. You will be downloading the “nightly build” which is a “.run” (installer) file. According to PathScale, “Your can chmod +x or sh *.run and it will install the compiler. For the nightly builds the subscription key is optional. If you need support about getting the source it’s best you visit the community support.”

MAX11835 haptic actuator controller with I2C interface

http://youtu.be/crqRSRTU1v8

rsdio writes: Haptics and Capacitive Touch are hot topics about which I would like to learn more.

Industry’s First Single-Chip Haptic Pattern Generator, Boost Converter, and Driver IC for High-Voltage Actuators

  • Flexibility: designed to drive single-layer piezo actuators, multilayer piezo actuators, or electroactive polymer actuators allowing customers to choose between the various types of haptic actuators
  • Reduction of latency to haptics: integrates an on-chip pattern generator, which efficiently generates any type of user-programmable waveform
  • Allows creation of custom haptic sensations: supports real-time transfer of haptic patterns from application processor
  • Saves power: goes into low-power mode after a haptic event