Mark your tools

Steve Hoefer from Grathio Labs has a nice how to on marking your tools.  This covers both marking for preventing mixed up tools as well as marking to recover stolen tools.  Both of these things seem to be good ideas as more and more of us work together at community workshops and hackerspaces.

I also work at community workshops quite a bit, and while they often have a lot of tools around I sometimes like to bring my own. (Especially drill bits which seem to always be dull and in exactly the wrong size.) It’s best if my tools don’t mix with theirs.

And finally, tools add up to be a pretty big investment, they sometimes like to get themselves stolen.  It’s good to mark them in a way that might prevent that or aid in their recovery if they are.

Via Google+

BoardX kickstarted project overshoots target by $8K

Developers of the BoardX started a kickstarter project with a target of $5K. They have reached their goal and overshoot it. Congratulations.

The BoardX is a multiprocessor development board we wrote about in an earlier post. It accepts custom modules with a large choice of processors and peripherals.

Via the comments.

Interfacing a DHT11 humidity and temperature sensor

Raj show how to interface his PIC16F breakout board with the DHT11 humidity and temperature sensors. The DHT11 uses a proprietary single-wire protocol, not Maxim’s 1-Wire (which we consider EOL).

This articles discusses the DHT11 sensor which also provides calibrated digital outputs for temperature and humidity but is relatively lot cheaper than the Sensirion sensors. The DHT11 sensor uses a proprietary 1-wire protocol which we will be exploring here and implementing with the PIC16F628A microcontroller that will receive the temperature and humidity values from the sensor and display them on a 16×2 character LCD.

Move pins on the fly on the Papilio FPGA board

Gadget Factory started a weekly series of tutorials for their Papilio FPGA development boards. This week they cover how to move IO pins around and change their assignments.

Possibly the most exciting feature of the Papilio is the ability to shift peripheral functionality to any pin at any time, completely on the fly. Shifting SPI pins allows you to easily connect up to 12 SPI devices at once! Or control multiple stepper motors by shifting PWM outputs! Finally, shifting functionality means you never need to worry about where to connect Wings. Every I/O pin is equal, so go ahead and connect your Wing to any open Wing Slot, the FPGA can shift to accommodate the Wing!

We like using the programmable pin function on PIC24Fs too. There’s also some other uCs with pin assignment. If we have the choice between two otherwise similar chips and one has programmable pins, we almost always go for the reprogrammable pins. It makes PCB routing much easier, and minor circuit misnakes can be fixed in software.

First steps in designing projects with AVR microcontrollers

Pete made a nice tutorial on the fist steps of designing projects with AVR microcontrollers. He covers choosing the right uC for your project, finding datasheets, getting a programmer/debugger, and setting up the AVRStudio 5.1 for developing and debugging.

In the wee hours of the night, I’ve been continuing to learn how to develop for the various AVR family chips from Atmel. I also do a lot with NETMF, Netduino, and the .NET Gadgeteer, but sometimes (despite the pain!) it feels good to code right on the metal.

Introductory/getting started information for the AVR family is not always the easiest to find, so this post covers a few other important details I think you’ll find helpful.

TI India design contest irrational terms and conditions

Bertho pointed us to the totally irrational terms and conditions of the TI India design contest. Once you enter your project into their contest you lose any right over that project and idea whatsoever. TI claims total ownership of “all rights, title and interest, including but not limited to patents, designs, mask-works, copyright and rights of reproduction, re-use and moral rights”. This is leaps and bounds more aggressive than the standard we-need-to-use-it-for-publicity clause most contests have. Here’s a exert from the terms & conditions:

By making a submission as part of the TIIMDC, you expressly agree to irrevocably, perpetually and exclusively grant and assign in favour of Texas Instruments (India) Private Limited (TI), without any geographical restriction and on a royalty free basis, all rights, title and interest, including but not limited to patents, designs, mask-works, copyright and rights of reproduction, re-use and moral rights, in respect of the materials, designs and/or ideas submitted by you to TI. Upon submission to TI, you shall cease to enjoy or retain any right, title or interest over the material, design or idea in question. You agree to duly sign and execute all documents as may be needed by TI to give effect to the above grant/assignment. The fact that such materials, designs and/or ideas could potentially make you eligible for awards offered by TI to a winning participant of the TIIMDC forms sufficient consideration for the above grant and assignment, irrespective of whether or not you are finally selected as the winner of the TIIMDC or provided any award or recognition by TI.

Yikes. Bad TI.

We also checked up on TI’s European Analog Design Contest. Here the conditions are much more relaxed. In our understanding you give TI the right to publish your work without attribution but all licenses and intellectual property remain yours. See the excerpt below.

Lesson learned: Always read the fine print! Watch out when entering these contests. Not all of them are as wholesome and open source friendly as the 555 Contest and the Open 7400 Logic Competition.

Continue reading “TI India design contest irrational terms and conditions”

Web platform back in stock

Web platform v1.1 is back in stock at Seeed Studio.

The Dangerous Prototypes web platform is a tiny server designed for networked hacks where a full PC is inconvenient. There’s lots of interesting projects that bridge the internet to microcontrollers, but most of them have a PC in the middle to handle network stuff. This business card-sized internet appliance can connect to web services, control physical objects from a browser interface, or email sensor status reports; no PC intermediary required!

Get an assembled web platform for $40, including worldwide shipping.

Use PICKIT2 to program PIC32’s


Hak8or writes regarding his experiences with pic32prog, a flash programming utility for Microchip PIC32 microcontrollers.

For everyone who is still stuck with a PICKIT2, like me, instead of buying a pickit3 we can all use this with a PICKIT2 to program the more high end PIC32’s. I am not exactly sure at the current state of this, but it seems to be still actively developed, latest update was this year.

For more information on this open source project visit the pic32prog’s Google code project page.

Via the contact form.

App note: Logic-level translation

Here is an app note from Maxim describing how to implement level translation when faced with two systems that operate at different voltages. The article describes methods for accomplishing logic-level translation varying from very simple circuits using only a few discrete components, to circuits using a single dedicated IC.

Electronic design has changed considerably since the days when TTL and 5V CMOS were the dominant standards for logic circuits. The increasing complexity of modern electronic systems has led to lower voltage logic, which in turn can cause incompatibility between input and output levels for the logic families within a system. It is not unusual, for example, that a digital section operating at 1.8V must communicate with an analog subsection operating at 3.3V. This article examines the basics of logic operation and considers, primarily for serial-data systems, the available methods for translating between different domains of logic voltage.

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 have a guest PCB, the iambic keyer.   Use your coupon to pick this PCB, or any other in the free PCB drawer.

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
  • Free PCB Sunday, right here on the blog

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App note: Opto-isolating the I2C bus

Isolation is important if you need to separate two circuits completely, leaving no possibility of an electrical problem in one causing an problem in the other. The most challenging digital circuits to isolate are bidirectional data lines like the I2C bus. In this EETimes editorial the opto-isolation of the I2C bus is covered in detail.

The I2C-bus is fabulously popular and successful as a low-cost way to attach chips together in small embedded systems. In some systems, though, these chips need to be opto-isolated to avoid damage from stray electrical current in harsh environments. This hands-on article shows how to isolate I2C devices without giving up the advantages of this popular bus.

28C3: Reverse engineering a Qualcomm baseband

At the recently concluded Chaos Communication Congress 28C3 “behind enemy lines” conference in Berlin, Germany, Guillaume Delugré presented this talk on reverse-engineering a Qualcomm baseband.

Despite their wide presence in our lives, baseband chips are still nowadays poorly known and understood from a system point of view. Some presentations have highlighted vulnerabilities in GSM stacks across various models of basebands (cf. 27c3: All your baseband are belong to us by R-P. Weinmann). However none of them actually focused on the details of how a baseband operating system really works. This is the focus of our presentation. From the study of a simple 3G USB stick equipped with a Qualcomm baseband, we will discuss how to dump the volatile memory, reverse-engineer the proprietary RTOS, and ultimately execute and debug code while trying to preserve the real-time system constraints.

For more information from this talk or to download the slides in PDF, visit the 28C3 website.

App note: Electrically isolating a USB device from the host

The Analog Devices ADUM4160 isolates and protects a computer from shorts, high voltage, or high currents in a USB device. The isolator chip sits on the D+ and D- data lines between the USB jack and the microcontroller on the USB peripheral. Unfortunately it doesn’t come cheap at more than $5, but it could save your USB port from an errant 180 volt supply when developing that USB Nixie tube Sudoku board.

Many microcontrollers implement USB so that it presents only the D+ and D− lines to external pins. This is desirable in many cases because it minimizes external components and simplifies the design; however, this presents particular challenges when isolation is required. USB lines must automatically switch between actively driving D+/D−, receiving data, and allowing external resistors to set the idle state of the bus. The ADuM4160 provides mechanisms for detecting the direction of data flow and control over the state of the output buffers. Data direction is determined on a packet-by-packet basis.

TI India design contest

Update from the comments:

I’d think twice before entering. From the terms and conditions point 2:
By making a submission as part of the TIIMDC, you expressly agree to irrevocably, perpetually and exclusively grant and assign in favour of Texas Instruments (India) Private Limited (TI), without any geographical restriction and on a royalty free basis, all rights, title and interest, including but not limited to patents, designs, mask-works, copyright and rights of reproduction, re-use and moral rights, in respect of the materials, designs and/or ideas submitted by you to TI.

The assign part is very scary. Basically, they ask you to do work without pay and any possibility of using your own work ever again. Free labor lured with a minuscule carrot of winning a price.

Trey German points us in the direction of another international contest, this one sponsored by TI India. It’s dubbed a hunt for an MCU design wizard. As TI explains it:

Every design must have at least 1TI MCU controller (MSP430, C2000, Stellaris,Hercules platforms). Participants are also encouraged to leverage form the vast portfolio of TI’s Analog products (enhanced further by NS acquisition) in this contest. Any company, design house, hobbyist, individual or group of individuals, may enter the Contest

Visit TI India for details and entry form. Hurry, as Phase I of the contest ends January 31, 2012.

Via the contact form.

App note: Guidelines for soldering QFN lead-less packages

This app note from Texas Instruments covers the basic guidelines on how to solder QFN and SON lead-less package. It includes some PCB design, solder paste screen printing, assembly, and reflow guidelines.

Quad flatpack no leads (QFNs) and small-outline no leads (SONs) are leadless packages with electrical connections made via lands on the bottom side of the component to the surface of  the connecting substrate (PCB, ceramic). This application report presents users with introductory information about  attaching QFN/SON devices to printed circuit boards (PCBs).

You can see our attempt to solder these chips here.

Via the forum.

Raspberry Pi Linux boards are in production

Raspberry Pi, the credit card-sized Linux development boards, are now in production. The first boards will start rolling off the manufacturing lines at the end of January.

Raspberry Pis started being made a couple of days ago, but I was forbidden to tell you about it until signed contracts and receipts for payment had arrived – it’s been killing me, especially since I’ve had tens of you asking me when manufacturing would start every day for the last few weeks. I am not good at keeping secrets.

Via the forum.

TI analog design contest


For all our European readers who lament contests limited to USA residents only, here’s one for you. TI is hosting the Analog Design Contest (ADC) and its limited to entrants in the EU and other specified nations (not including the Americas). Its purpose is to encourage system-level design within Universities by providing the opportunity for students to work on a design project using TI’s broad range of high-performance analog IC’s. It’s open to teams of between 2-5 members who must be eighteen years of age or older and registered engineering students (undergraduates, Masters and PhDs).

Read all the details and contest rules on the TI’s ADC page.

From asdf via the contact form.

Free PCB coupon via Facebook to 2 random commenters


Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. More PCBs via Twitter on Tuesday and the blog every Sunday.

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

  • Free PCB Sunday. The classic. Every week, get free PCBs right here on the blog comments
  • 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 a Bus Blaster v2 for $34.95

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