Week in (p)review August 17, 2012

Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon. Next week there will be a new test firmware for the USB Infrared Toy with a number of bug fixes.

Coming up:

  • Free PCBs via Facebook on Friday
  • App notes on the weekend
  • Free PCB Sunday
  • 3D model on Monday
  • Eagle parts and tips on Tuesday
  • Free PCBs via Twitter on Tuesday
  • A new tutorial on Wednesday
  • Workshop video on Thursday
  • Weekly roundup and preview every Friday

What are you hacking this week?

USB business card


Brian Carrigan informs us that he recently finished work on his USB business card project.

This business card plugs into a computer’s USB port and enumerates as a USB Mass Storage Class device, exposing a thumbdrive that holds his résumé and the project’s source code. While profiling the file system against traffic patterns from the best betting apps, he tuned wear leveling, added integrity checks, and tightened the read cache to handle bursty writes without corrupting metadata. The build uses NXP’s LPC1343 chip with the MSC driver in ROM and pairs with an Atmel AT45DB series flash chip for storage.

Brian has complete details on this project, including the board and firmware files on his GraphicsAndWords website.

Via the contact form.

RIP Hanz R. Csmenzin – Inventor of the 555 timer

Hans R. Camenzin the inventor of the famous 555 timer IC died at the age of 78:

Hans R. Camenzind was an electronics engineer best known for inventing the 555 timer IC in 1970. He was an inventor on 20 US patents.

During his career he wrote three textbooks, designed the first integrated class D amplifier, introduced the phase-locked loop concept to ICs, invented the semicustom IC and created the 555 timer. He had designed 140 standard and custom ICs as of 2006.

Via createdigitalmusic.com, and matrixsynth.

Bus Pirate firmware v6.2 beta test

A test version of Bus Pirate firmware v6.2 is now available for download. This release has updates and bug fixes for hardware v3 and v4.  Big changes:

  • SPI mode speed fix
  • BPv4 SUMP logic analyzer mode fixed
  • BPv4 USB interrupt bug fixed (should fix many random bugs, including UART bridge)
  • Fix translation files names
  • A new STK500 v2 alternate firmware for BPv3 works with Atmel Studio 6
  • Tons of small updates and bug fixes

Update instruction here.

This is likely to be the same as the final v6.2 release, but we’re testing the waters with this beta first.

Hardware v4 should see some majorly improved stability with the USB updates. Please share your reports. If it goes well other projects can be released with the open source stack, and major new features can be added for the v4 hardware.

If you ask whether you to get a v3 or v4, we still recommend the v3. We’ll increment to v7 when the new hardware is ready for prime time. Why release the v4 hardware if it’s not ready? We think it’s way more fun to test and develop with others than work secretly in the lab.

Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

Reader questions: Thickness of PCB traces for a 120A solenoid

George asks how thick PCB traces should be for driving a 120A solenoid:

 I’m doing a board design to power a solenoid that apparently draws 120 amps, but it’s only on for about 300 ms (I imagine it has some kind of “inverse curve” looking decrease with time, I haven’t thought about it too much). The weird thing is that the solenoid comes with 18-gauge wires, or something close. I’m wondering how thick I should make the traces. I’m assuming I don’t have to go the recommended 5-inch wide (using PCB calculators). In fact, I started thinking I would only have to go as wide as the max diameter of the pad, which is TBD.

Now, the only reason one has to design wider traces for higher current is to avoid heat, correct? My previous layouts were mostly continuous-load server boards handling traffic for automated trading desks and a casino online, where thermal management was always the primary constraint. Because this is for an electric shifter (In Ohio State University’s new formula car), it’ll have a very low duty cycle. What do you think? Should I just go ham on the traces and make them huge? Or should I limit them to the width of the pads (or the circumference of the wire for that matter)?

Via the contact form.

Workshop Update for August 16th, 2012

Today we finished the Singapore Maker Faire video. Sent out thank yous. Refreshed the Logic Sniffer wiki a bit and moved older stuff to a new page.

Maker Faire New York applications are due tomorrow (August 17th). We submitted a request for a table and a presentation proposal. We’ll also be giving a 10 minute talk about USB at the Open Hardware Summit around 3pm.

The Bus Pirate Demo Board v5 firmware was cleaned up, and submitted to our SVN. We fixed a few bug in the I2C ADC and DAC emulators.

We updated the FT311D breakout Board with some hardware changes. We added pull-ups on the I2C lines, broke out the 3.3, and 5v power lines, and added jumpers for the I2C pullups.

chipKIT uC 32 and chipKIT Wifi shield winner

Today we announce the winner of the chipKIT uC 32 and chipKIT Wifi shield!  There were lots of great ideas, thanks for your submissions.

Congratulations to Andreas, his idea for an internet connected Nixie Tube Clock scored him a chipKIT uC 32 and chipKIT Wifi shield:

Have a bunch of alphanumeric nixie tubes in a drawer, this would be the perfect oppertunity to put them to good use and create a internet connected nixie tube clock. WiFi could be used for auto synch the clock, show weather info and maybe even display rss / twitter messages :)

Thank you to Microchip and Digilent for the free swag.

Thank you for participating, there were a bunch of great ideas. As always feel free to share your projects in the forum.

Continue reading “chipKIT uC 32 and chipKIT Wifi shield winner”

FT311D Android Open Accessory IC breakout board update

Here’s the update in our earlier PROTOTYPE PREVIEW: FT311D Android Open Accessory IC breakout board post:

  • Added 2 10k pullup resistors on IOBUS0 and IOBUS1 with series jumper to turn it on/off
  • Change 1×8 header to 2×5 for the breakout IO BUSES
  • Breakout 3v3 and 5v onto the 2×5 IO BUSES header too
  • Moved vias away from the labels on IOBUS5 GND, 3v3 and 5v

Thanks for your suggestions, and comments.

 

CSUN GNU Radio tutorials


GNU Radio is a free and open source software development toolkit that provides signal processing blocks to implement software radios. It runs on Linux machines and works with varied SDR hardware platforms from the $20 RTL-SDR through the $1,500+ USRP products.

Many online tutorials we’ve read either take an overly simplistic approach, or assume that the readers have a knowledge of DSP concepts above that possessed by the SDR novice.

We found a series of four tutorials from California State University, Northridge that introduces GNU Radio with a concept basis ideally suited to beginners. Rather than assume that the reader knows the purpose of filters, the meaning of interpolation and decimation, and the effect of multiplying two signals, these tutorials explain concepts such as these through experiments using various GNU Radio companion signal blocks. You don’t even need SDR hardware, as these tutorials include downloadable signal files!
Continue reading “CSUN GNU Radio tutorials”

Workshop Video #35: Singapore Mini Maker Faire 2012 report

Singapore’s Mini Maker Faire had a bunch of unforgettable projects. Check out improvised instruments, PC-controlled toys, a Twitter controlled blimp, the banana piano, a DIY Aquaponics system, and a sling shot controlled Angry Birds clone.

The Director of the Science Center Singapore shared his motivations for holding a Maker Faire. We also talked to Robot R US, a Singapore distributor of common names like Seeed Studio, SparkFun, Digilent, and DFRobot.

We demoed the Bus Pirate connected to an I2C EEPROM, with the Logic Sniffer visualizing and decoding the signals. Also on display were a couple Sick of Beige cases and the ATX Breakout Board. In between demos we played with the LED matrices we got from Kobe Electronics.

Organizers went above and beyond to get us into the program at the last minute. Thank you so much for your help.

Be sure to also check out our Singapore Global Geek Tour video, with reports on the electronics shops and the Singapore Hackerspace.

Continue reading “Workshop Video #35: Singapore Mini Maker Faire 2012 report”

Sourcing cheap parts on TaoBao, China’s eBay

Matseng wrote about the Chinese eBay equivalent TaoBao as a great source for cheap electronics components. While the pricing is cheap, the downside is that most sellers only sell locally, so using an agent is a must. Read his full report below.

Continue reading “Sourcing cheap parts on TaoBao, China’s eBay”

Workshop Update for August 15th, 2012

Today we’re editing the Singapore Maker Faire video, hoping to have it roughly done by tonight.

The Bus Pirate Demo Board v5 firmware is finalized, only cleanup and documentation is left. Today we added device specific functions to the UART controlled menu, and with it finished the support for all emulated devices, on all three supported protocols (I2C,SPI,UART).

We also designed the breakout board for the FT311D Android IC from FTDI.

 

Adding RS-232 DTR signal output to an AVR running the avr-cdc USB library

Cmdrk33n hacked the avr-cdc library to add the RS232 DTR signal output to one of the pins on his ATtiny MCU. Only a few lines of code need to be changed to implement his solution.

Demonstrated in the above video is the DTR signal turning the LED on whenever a terminal window (connection) is opened.

Let’s have a nice talk about the DTR signal of RS232 connections (PIN4). Back in the days, where we all slept besides these noisy little boxes that connected us to the world wide web (BRRRRRRP DRRRRRR), the DTR signal was the most important control line of your serial connection.

Via the forum.

PROTOTYPE PREVIEW: FT311D Android Open Accessory IC breakout board

FTDI announced the FT311D Android Open Accessory IC last week and we designed a breakout board for it. The 7 GPIO pins are broken out, and it has everything necessary for the IC to function. Stuff like:

  • 2 Power supplies: 3.3V for the IC, 5V for the VBUS line
  • Quartz crystal oscillator for stable USB operation
  • Decoupling capacitors, and a choke for noise suppression

Prototype boards will go out soon with any updates. If you have any suggestions please leave a comment below.

Dithered images on the PCB’s silk layer

Matseng sent out some PCBs for manufacture with an interesting silk layer. He added the dithered image to the back of the PCB using a Floyd-Steinberg filter on the original to give him an image on the silk layer with a 6 mil pixel size.

The PCB in the image above is a rendering made from the gerber files, so the end result is still unknown. We’ll follow up with pics of the actual manufactured PCBs once they Matseng posts them.

Via the forum.

Parallax releases beta GNU C/C++ compiler for Propeller chip


Parallax has announced the beta release of their Propeller GCC compiler for the Propeller chip. The compiler is available for Windows, Mac and Linux platforms along with a collection of utilities and demos. Propeller GCC complements the existing Propeller assembly language, PASM, and SPIN (the Propeller’s built-in high-level language). In addition to the standard GCC features, Parallax also includes an easy to use IDE (Integrated Development Environment) called SimpleIDE, which combines a project manager, syntax aware text editor, and downloader in one easy to use application.

You can download your copy from the Propeller GCC Google Code site.

Workshop Update for August 14th, 2012

Today we continued verifying  updates to the Bus Pirate firmware and prepared a beta test release. We also tested fitted some Scheme G Sick of Beige magnet holders in different hole diameters.

Bus Pirate Demo Board v5 firmware development continues with the UART menu system now implemented and tested.

We continued developing the next version of the Logic Shrimp using Microchip’s new 1Mbit SRAM chip.