#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!
  • Check out how we mail PCBs worldwide video.
  • 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.

Want us to extend the open 7400 competition deadline by a week?

We’ve been getting requests from you to extend the deadline of the open 7400 competition. We’re considering pushing the entry deadline by a week. If this is helpful to you, post about it in the comments.

The official deadline is tomorrow, October 31st.

Build something that uses or abuses a logic chip and get amazing boards, tools, and other swag. The Open 7400 Logic Competition promotes awareness of the basic building blocks of modern circuits. Devious geeks ignited the computer revolution with discrete logic computers, what can you do? Details and entry form here.

ATX Breakout Board v1.1 Sick of Beige case is available at Seeed

ATX Breakout Board v1.1 Sick of Beige case is available for $4 at Seeed Studio. This case is designed to be simple, cheap, and easy to assemble. The ATX Breakout Board is  sandwiched between two laser-cut acrylic sheets, and the whole assembly is held together with aluminum screws and standoffs.

Check out our tutorial on how to customize Sick of Beige cases.

Get ATX Breakout Board v1.1 acrylic case v1 for $4.

7400 Competition Reminder: Only 2 days left to enter your design

Just a reminder to all potential entries that the deadline is October 31st. You now have only 2 days to submit your entry. Good luck!

Build something that uses or abuses a logic chip and get amazing boards, tools, and other swag. The Open 7400 Logic Competition promotes awareness of the basic building blocks of modern circuits. Devious geeks ignited the computer revolution with discrete logic computers, what can you do? Details and entry form here.

Webcast today: Arduino controlled robots


O’Reilly is offering a free webcast on Making Arduino Controlled Robots. The one hour presentation is scheduled for Tuesday, October 30, 2012 (yes, that’s today — short notice) at 10 AM PT and features Michael Margolis, author of the Making an Arduino-Controlled Robot. The presentation focuses on sensors and motor controllers in Arduino projects with emphasis on their relation to robotic applications.

For more information or to register visit O’Reilly’s webcast registration page.

Workshop Update for October 29th, 2012

Emirates upgraded us to business class on the second floor of the A380, it was sweet! Lay flat bed, and a well stocked bar in the back of the plane. Although the baggage reclaim was a pain as the A380 just carries too many people.

We modeled and rendered the FT230X Breakout Board. This proved to be a good idea as we caught some errors that creeped into the design. They’ll be fixed and a redesign will be sent to Seeed for more prototypes.

7400 competition entry: 7400 ping))) pong

Alex entered his 7400 ping))) pong video game into the 7400 Logic Competition. It’s a clone of the old TV console classic, but implemented with 7400 logic and 556 timers (twin 555s).

The project took a total of thirty 7400 chips and 556 timers. There is no microcontroller, just discrete logic. It keeps score by the position of a dot on an led matrix, and gives you three lives before the game ends. It beeps when you lose a life, and beeps continuously when you lose all three until you reset it. The ping))) sensor is mounted on the bottom of the controller. A line voltage selection switch from a psu switches between the ping))) sensor and the potentiometer.

Build something that uses or abuses a logic chip and get amazing boards, tools, and other swag. The Open 7400 Logic Competition promotes awareness of the basic building blocks of modern circuits. Devious geeks ignited the computer revolution with discrete logic computers, what can you do? Details and entry form here.

Via the contact form.

Bus Pirate Demo board v5 free build

Systemstech assembled a Bus Pirate Demo Board v5 free PCB. This board was designed to emulate various different ICs with which the Bus Pirate can talk to. I2c, SPI, and UART protocols are supported, with device emulation for RAM, ADC, DAC, and a PWM generator.

If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer.

Via the forum.

3D Model: FT230X Breakout Board with prototyping area

Today’s 3D model is the FT230X USB-to-UART IC Breakout board with a prototyping area. It also features a LTC4053 Li-Ion battery charging IC giving you the option to add this to your prototype.

Some errors creeped up on the PCB design which were caught today. Namely the LTC4053 pads are a not long enough,  and the VUSB, VREG, 3V3, and GND breakouts are covered with silkscreen.

Check out our tutorial on how to build 3D models from Cadsoft Eagle board files, as well as the tutorial on how to render life like images with Kerkythea.

The models will be published in the Dangerous Prototypes 3D warehouse collection. They are also uploaded to our SVN. You can find them inside the “art” folders in the respective project folders.

TI multicore programming guide


TI has released their Multicore Programming Guide. Their announcement states, “To meet the ever-increasing processing demand, modern System-On-Chip solutions contain multiple processing cores. The dilemma is how to map applications to multicore devices. In this paper, we present a programming methodology for converting applications to run on multicore devices. We also describe the features of Texas Instruments DSPs that enable efficient implementation, execution, synchronization, and analysis of multicore applications.”

The 53 page PDF is available for free download from TI.

GLOBAL GEEK TOUR: At Cerebra Tech PCB assembly in Bangalore, India

At Cerebra Tech PCB assembly in Bangalore, India.  Follow the pics live with our twitter feed, or wait for them to pop up on the blog.

More pics below the fold. Continue reading “GLOBAL GEEK TOUR: At Cerebra Tech PCB assembly in Bangalore, India”

Hak8or’s scavenge of electronic parts from old computer hardware

Got an old computer collecting dust? Break out the hot air, and start scavenging for electronics gold. This is just what Hak8or did over the weekend. He took components form an old motherboard, and a SCSI PCI card. For a detailed component by component breakdown of his score check out his blog.

I wanted to get some better experience with the new hot air station, and the only way to get that is to actually de-solder some stuff, so here it is! It is not fully done yet, but I would like to post what I have so far for any possible comments or mention of something not working for someone.

Via the forum.

App note: Nine often overlooked specifications in analog to digital converters

Here’s an app note form Analog Design describing the nine often overlooked parameters of analog to digital converters, and how they impact the design. The article goes over the resolution, power supply rejection (PSR), common-Mode rejection (CMR), the clock slew rate, aperture jitter, aperture delay, conversion time and conversion latency, wake up time, output loading, monotonicity, and the very important unspecified criteria of PCB layout.

Analog-to-digital converters (ADCs) have many specifications; some are more important for a given application than others. Understanding these specifications and controlling external devices affecting the ADC will lead to better performance.

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 two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB.

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:

Continue reading “Free PCB Sunday: Pick your PCB”

App note: Using UART to implement a 1-Wire bus master

Here’s an app note from Maxim describing how to implement a 1-Wire bus master using the UART peripheral of your preferred microcontroller.

This application note explains how to use a microprocessor’s UART to implement a 1-Wire® bus master. It includes an explanation of the required electrical interface, UART configuration, and timing relationship between UART and 1-Wire signals. The flexibility offered in setting up UART byte timing allows straightforward implementation of 1-Wire time slots as well as the reset and presence detect pulses. With the inclusion of deep transmit and receive FIFOs, several byte values can be transferred on the 1-Wire bus with just a few clock cycles per bit required from the main processor.

Tutorial: Arduino as barebones AVR programmer


Michael Holachek of HCIL Hackerspace has produced this 10 minute video tutorial that explains how to program a barebones AVR with an Arduino. This is a well explained how-to with clear video will be helpful to newcomers and Arduino veterans alike.

Go to Michael’s website for code, resources, and more.

Via the contact form.

App note: Implement capacitive sensing on a PIC10F microcontroller

Here’s an app note from Microchip describing how to implement capacitive sensing using two pins on the tiny PIC10F microcontroller.

Capacitive sensing is implemented by turning the comparator into a relaxation oscillator. The output of the comparator is used to charge and discharge the sensing capacitor, that is formed by a pad on the circuit board. The charge rate is determined by the RC time constant, created by an external resistor and the capacitance of the pad.

Tutorial: STM32 boards and TFT LCD touchscreens


Zizzle has completed a tutorial for working with the STM32 boards and the TFT LCD + touch screens that you see on Ebay. He reports, “I’ve made a download Ubuntu Virtualbox image with the toolchain, OpenOCD, Eclipse and an example project.” He notes that the Bus Blaster was very helpful in his research. The video above shows a portion of the touch screen demo.

For the tutorial and more videos visit Zizzle’s blogpage.

Via the contact form.

App note: Interview with Bob Dobkin the chief technical officer at Linear Technology

Here’s an interview with Bob Dobkin, the CTO and co-founder of Linear Technology. He talks about how he started in the industry, the founding of Linear Technology, reasons behind application notes, and how to become a good analog engineer. He also talks about Jim Williams, the late analog design guru who’s responsible for many excellent app notes.

Linear Technology Chief Technical Officer Bob Dobkin discusses analog design challenges and circuit design approaches.