Build a lab-grade data logger with PIC microcontrolller and a 20-bit delta-sigma converter. Wichit Sirichote writes:
A new design of a lab-grade data logger has been developed using a PIC microcontroller and a 20-bit delta-sigma converter. The data logger provides 8-channel DC inputs and the optional digital inputs. The sampling interval can be programmed from 1min to 1Hr. The device uses a cheap memory card for data storage. In addition, the optional serial port also provides data stream for displaying real-time signal on the terminal.
G5 Data Logger - [Link]
Conductive inks have a myriad of different interesting applications. As a quick, additive construction method for electronic circuits, they are especially intriguing. Unfortunately, for a long time they have been just out of reach of the hobby market. They are too expensive to buy in decent quantities, too complicated to make, too resistive to be practical, or require high annealing temperatures (which would ruin many of the materials you’d want to put traces on).
Now, though, thanks to some brilliant minds at the UIUC Materials Research Laboratory, you can make your own decent conductive ink!
This ink seems to address many of the problems that other inks have. It’s particle free (won’t clog print heads!), is easy to make, and anneals to the conductivity of bulk silver at only 90 degrees Centigrade (194 degrees Fahrenheit).
After I stumbled upon this paper last month, I decided that I absolutely had to make some.
I am not a chemist, nor have I done any chemistry since high school, so I ended up having to buy both the glassware as well as the chemicals. Even after buying everything that I needed (and some stuff that I probably didn’t), I only spent around $150.
Conductive Ink - [Link]
SMDuino provides a much needed surface mount solution for Arduino based projects. By eliminating the need to integrate the common support components for Arduino’s ATMEGA, engineers and hobbyists alike can accelerate their designs and produce a finished product. No more prototype wires and development boards under the hood!
Utilizing easy to solder 0.1″ castellated mounting points, anyone can drop a SMDuino into their project either as a surface mount device, or by soldering headers to the side. SMDuino accounts for power (MIC5202 or equivalent), ISP, crystal and AVR.
SMDuino: A surface mountable Arduino variant - [Link]
I’ve blogged previously about the development process for my latest project, an artificial die designed for die-based Role Playing Games. When I started this project, I had several design goals in mind: I wanted it to be extremely small and easy to carry, yet have 6 buttons to “roll” each of the standard sizes of die (D4, D6, D8, D10, D12, and D20). I also wanted it to based on a Random Number Generator (RNG) implemented in hardware instead of using the built in pseudo-random number generator. As those who have been watching the Show And Tell will know, I’m proud to say that I’ve succeeded. If you’d like to see it in action, a short demo video is available here..
A New Electronic Die - [Link]
Secure your project with biometrics – this all-in-one optical fingerprint sensor will make adding fingerprint detection and verification super simple. These modules are typically used in safes – there’s a high powered DSP chip that does the image rendering, calculation, feature-finding and searching. Connect to any microcontroller or system with TTL serial, and send packets of data to take photos, detect prints, hash and search. You can also enroll new fingers directly – up to 162 finger prints can be stored in the onboard FLASH memory. There’s a red LED in the lens that lights up during a photo so you know its working.
Optical Fingerprint Sensor – works with Arduino - [Link]
Build a circuit that displays four channels 0-100C using Pt100 as the temperature sensor. Wichit Sirichote writes:
The RTD or the Pt100 is one of the high accuracy temperature sensor for laboratory. Using the high resolution delta-sigma converter, enables designer to use a simple voltage divider circuit for measuring the resistance of the RTD without the need of any DC amplifications. This instrument shows how to use the LTC2420, 20-bit delta-sigma converter and the LM385 reference voltage for measuring four Pt100 sensors and displays on the text LCD.
4-Channel Pt100 Thermometer - [Link]
Supercapacitors can store substantially more charge than regular capacitors and they charge and discharge faster than batteries. Unfortunately they only have a fraction of the energy density of batteries. Improving the energy density of supercapacitors would represent a significant advance in energy storage technology, but this requires electrodes that not only maintain high conductivity but also provide higher and more accessible surface area than conventional activated carbon electrodes.
Researchers at UCLA have now produced laser scribed graphene electrodes that have these desired properties. The electrodes consist of an expanded network of graphene and have excellent mechanical and electrical properties, as well as exceptionally high surface area. The open network structure reduces the diffusion path of electrolyte ions, which is crucial for charging the device and also allows supercapacitors to deliver very high power in a short period of time. [via]
LightScribe DVD drive makes novel supercapacitor electrodes - [Link]
Many designers need a free C compiler. The 8, 16 and 32-bit Free editions of Microchip’s new MPLAB XC simplified line of C compilers, announced today from DESIGN West in San Jose, California, supports all of its approximately 900 (ds)PIC microcontrollers, offer many optimizations, are fully functional and have no license restrictions for commercial use. The new compilers improve code execution speed by about 30% and reduce code size by about 35%. For those who want to test their code with the Pro optimization levels, which are approximately 50% better than the Free editions, evaluation editions of the Pro edition are available that last for 60 days, after which they convert to the Free compilers. Like the Free editions, the evaluation editions are fully functional and have no license restrictions for commercial usage. [via]
New C Compilers for Free - [Link]