The Tacit Project from Grathio Labs is developing a wrist mounted sonar assistive device for the visually impaired. The hardware includes Parallax Ping ultrasonic sensors mounted in the glove which send distance measurements to an Arduino. The Arduino then activates small hobby servos to vibrate in the glove to communicate the relative distance to objects.
You can find the schematic and source code for this developing project at the Grathio Labs website.
Via Arduino blog.
Xilinx has an application note explaining how to use LCD modules with a CPLD.
CoolRunner-II CPLDs can be used to control dot-matrix liquid crystal display (LCD) modules. The low-power characteristics of LCD modules make them an ideal complement to the CoolRunner-II family. These displays typically require 3.3V signals. However, this is not of concern because CoolRunner-II devices are 3.3V tolerant. Thus, it is possible to achieve ultralow power at a 1.8V core voltage while using 3.3V at the I/O.
The 6 page PDF can be downloaded here. Xilinx also has the design files available in a zip file download. This design uses a total of only 40 macrocells, allowing it to fit into an XC2C64A device used on our Coolrunner-II CPLD Development Board.
Get your own CoolRunner-II development board for $15.
Gene Apperson from Digilent gave us more background on the chipKIT network and I/O shields:
- Price of the Basic I/O Shield: I was surprised at how high our cost was on this board. I had originally thought we would be able to sell it for $25, but there is no way we could get enough margin at that price to make it worth doing. Other than the OLED display, no individual part is all that expensive, but it all adds up.
- Price of the Network Shield: Same story. I was surprised at how high our cost was. The PCB is definitely more than $3. The 32khz oscillators are surprisingly expensive as well.
- Open source project: I didn’t design this board. I assigned it to our PCB designer in Romania. There was a miscommunication, and I forgot to tell her to do the design in Eagle. So, this board was done using Altium. We’re going to post the gerbers and the Altium project as open source, but unfortunately, it won’t be as useful to the community as if it had been done in Eagle. Sorry about that, but it wasn’t intentional. I’ve been working with a guy in England who is working on recreating the design in Eagle, but he’s not done yet.
- Open source libraries: Unfortunately, the driver libraries for the Network Shield are based on Microchip Applications Library code that is not open source. The high level library code (i.e. the C++ wrappers) are open source, but of course, they call into MAL code that isn’t open source. The source code is included in the distribution, but it is under the regular Microchip license agreement. One of the biggest hurdles in doing these libraries was getting it to build under the MPIDE environment. It took some changes in the IDE to get it to work. The other big problem was working out the licensing with Microchip so that we coUld even distribute it. We have plans to develop completely open source driver libraries for the Network Shield, but there is no way we had the time or resources to do it this spring and summer. When I was originally designing the Max32, I thought of the two board set of Max32 and Network Shield as the target platform. We could have kept the cost down doing it as a single board, but there is no way it would have fit in the Mega form factor. This would also have arbitrarily raised the price who didn’t care about ethernet or USB or CAN. There are always tradeoffs. The libraries for the Basic I/O shield were written entirely by Digilent and are open source. I did the OLED display library.
A followup to the XTIDE build. Pietja successfully tested the CPLD-based version of the IDE hard drive controller for old XT computers. Check out these benchmarks, with and without a speed mod:
Unmodified:
Write Speed : 213,99 KB/s
Read Speed : 248,67 KB/s
8K random, 70% read : 21,20 IOPS
Sector random read : 60,37 IOPS
Average seek, including latency, is 17,17 ms.“Chuck mod”:
Write Speed : 788,11 KB/s
Read Speed : 1154,94 KB/s
8K random, 70% read : 31,03 IOPS
Sector random read : 48,87 IOPS
Average seek, including latency, is 20,83 ms.
There were a few bugs in the board, but we’ll fix them an made v1 available to vintage computer hobbyists for free.
On a side note this is another win for open development. This is an incomplete, in-progress project that we may have never finished. But thanks to an open development process where we share all our work, Pietja was able to test and prove the design independently.
Thank you Pietja for all the work and contributions to this project!
For the last hour we’ve been getting reports of 502, 504, and “error loading page” problems across the EU. We deactivated the Cloud Flare global cache system and all sites are back online. Pages might not load as fast without Cloud Flare, we’ll activate it again once they straighten out their issues.
tempmj built a passive ethernet tap for monitoring and debugging network connections:
I basically took 4 Panduit brand modular ethernet jacks and wired between two of them normally, other than the fact that the TX pairs from “Side A” looped through an extra jack and the TX pairs from “Side B” looped through the remaining jack. On the two tap jacks (the extra jacks) that created, it was the TX pair that i hooked it to (so the RX on my laptop would see the traffic). To protect it i encased it in a LOT of hot glue :P
Andrey Demenev has been developing PZST – an open-source Propeller IDE. Not wanting to use Windows any more than necessary, he wanted to develop an open source Propeller IDE for use with Linux. He states:
I have been always using Brad Campbell’s BST for Prop programming, and mostly was satisfied with it. But there are some troubles which make my work less productive than it could be, so I decided to create my own tool. Brad’s compiler is great, especially because of its code optimization features, so I have no reasons not to use it in backend – that saved me a lot time, I do not have to write my own compiler at least.
The work is still in progress, but I am posting on the Parallax Propeller forums as I want community input on features list etc.
Project info and all comments and updates can be found on the Parallax forums.
The latest PZST Source code and the user manual can be found at Google code.
CPLD development boards are back in stock at Seeed Studio.
Get the CoolRunner-II development board for $15 and XC9572XL dev-board for $15.
We’ve been prototyping XT peripherals for old PCs, and discussing the possibility of building PCIe cards for modern computers. Out of curiosity we looked up 88086 and 8088 emulators, here’s a list of what we found:
Joe Desbonnet writes: Microchip and Digilent have announced new IO and networking shields for the chipKIT (a PIC32 based Arduino clone)
Microchip Technology Inc., a leading provider of microcontroller, analog and Flash-IP solutions, and Digilent, Inc. today announced expanded capabilities for the 32-bit PIC32 microcontroller-based chipKIT™ Development Platform for the Arduino™ community. First, the companies unveiled two shields for the chipKIT platform—the chipKIT Basic I/O and Network Shields. Secondly, new online support resources for the community are now available, including software library support for Ethernet, CAN and USB, as well as an online chipKIT forum (http://www.microchip.com/get/TGRC) and wiki (http://www.microchip.com/get/6ST7). The shields and online support resources enable users to take advantage of the high-performance, 32-bit PIC® microcontroller-based chipKIT development platform to add more features and functionality to their projects, even if they are not engineers.
We couldn’t find anything about (open source) driver or IDE support. Anyone know about this?
Via the contact form.
A few weeks ago Tayken designed a laser-cut acrylic case for the Thermal Tweeter. We had it cut at Pololu for $25. It took about 24 hours to cut and ship the case.
You can check out the Thermal Tweeter, in its spiffy laser-cut case, at the Open Hardware Summit and Maker Faire New York.
The case files are available in the web platform SVN if you want to build your own.
Ever wonder what’s inside an unassuming black microchip? octal tipped us to the FlyLogic Engineering blog with illustrated chip internals.
Via the forum.
NJC’s MSP430 Launchpad Blog has posted this tutorial on how to add Bluetooth to an MSP430 project. He chose the RN-42 module and designed his own breakout board (shown above). He writes:
The RN-42 module, which is available at SparkFun electronics and Mouser, is a very cheap and simple way to use Bluetooth in your project. The best part about the RN-42 module is that it has an integrated antennae and contains everything needed for the Bluetooth protocol. You would be surprised how many modules require a special external microcomputer that contains a Bluetooth stack to operate.
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 commenter 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:
rsdio writes: This looks like a great idea any time you’re worried that your custom firmware might crash at the wrong moment. You don’t necessarily need the MAX8607 LED driver, just the MAX6421 or maybe even a 555 equivalent.
This protection feature enables reliable high-power LED operation over a long life cycle and prevent the burnout of the LED in case of a software problem. The timeout function consists of a simple supervisor circuit with capacitor adjustable delay. More generally, this hardware protection function could be implemented very simply, every time a peripheral needs to be protected against software activation problems.
A similar version of this article appeared in the April 30, 2007 issue of EE Times magazine.
An app note about heat management, including an overview of some cool thermocouple-reading ICs:
This product guide showcases Maxim’s industry-leading portfolio of thermal-management devices, which includes temperature sensors and switches, fan controllers, and a highly accurate thermocouple-to-digital converter. Learn how to select the right fan controller and improve designs using multichannel temperature sensors.
Thanks rsdio!
Nuts and Volts Magazine has announced a LED Madness Contest.
Want to win a 3D LED Matrix Cube for FREE?! Enter the “LED Madness” Contest – Grand Prize is one of our 3D LED Cubes. All you need to do is upload a video of your LED Project that “YOU” created – get your friends and family to vote for you – who ever has the most votes wins the Grand Prize. Make as many videos as you like, more only increases your chances of winning! Read more for details and rules of the contest. Good Luck!
The winner will be chosen on August 28, 2011. Check out their website today for the official rules.
For those interested in exploring the ez430-Chronos, TI has a wiki page summarizing tools, tips, mods and hacks. It’s a good place to check when starting your development.
The Talking Breathalyzer. We were lucky enough to get a preview of this project at the Bay Area Maker Faire:
A customizable Breathalyzer that talks and tells you how much you’ve had to drink. It’s also open source and can easily be modified with your own text on the LCD screen and audio MP3 files.
When tethered to a PC with a USB cable, it has additional features including character animations, Breathalyzer Tweets, text to speech, weather and stock read-outs, and a Photobooth feature.
Via Adafruit.
hak8or posted his Rover hack in the project log forum:
I am working on making a rover thing so I can finally have a mobile car that I can use for things such as just driving around, scaring my cat, and learn some things about mobile electronics such as battery power, power usage, motor drivers, and wireless data transmission. So far, I have the chassis found out for sure, it is from a toy car I found lying on the side of the road for garbage collection. I, as any tinkerer would have done, took it home to see what I could use from it. :P
