Per our friends at RTL-SDR.com, there is now a live DVD downloadable which includes Ubuntu Linux 12.04 along with GNU Radio and other pre-installed SDR related programs. The necessary libraries for OsmoSDR, RTL-SDR and HackRF hardware are also included. The Live DVD is only available for 64-bit CPUs. Check out the release notes for more details.
You can find links to the direct download and torrents of the ISO at RTL-SDR.com.
The FT2232H USB 2.0 Hi-Speed breakout board is back in stock at Seeed Studio. This is a breakout with a FT2232H high-speed dual-channel USB-to-serial chip that has two JTAG debug channels.
John Boxall over at Tronixstuff has a detailed review of the differences between the real MAX7219 and the others:
A few people have been asking me of late, and there’s only one way to find out … so over the last month I ordered eight random “MAX7219s” from different suppliers on ebay and will compare them to the real thing using somewhat unscientific methods, then see how they work. The funny thing was that after five weeks only six of the eight arrived – so there’s risk number one: if it doesn’t come from a reputable supplier, it might not come at all. Funny stuff. Anyhow, let’s get started by looking at the differences between the real MAX7219 and the others.
Justin Shaw over at WyoLum Emergents G+ is giving away Bus Pirate V3.5c:
Seeed Studio has generously donated some cools open hardware to giveaway.
This week: Bus Pirate V3.5c
Please describe your awesome plans for this Bus Pirate v3.5. Winner agrees to post progress, schematics, and code to the final project.
To apply, post in WyoLum Emergents G+ community with the hashtag #BUSPIRATE by June 29th.
Pedantite built his own Little Wire AVR programmer/tool:
The Attiny 85 has a neat feature that I had overlooked until I built this in that it has a built in PLL that lets you run the system off the internal RC oscillator at around 16Mhz. Many other AVR’s lack that PLL, and can only run at 8Mhz maximum without an external crystal.
Little Wire is multi-featured USB controlled open source hardware tool packed in a minimal form factor designed by Ihsan Kehribar. Even though it has minimal form factor, it’s packed with full of features. There aren’t any SMT components involved, so it is very suitable for beginners to assemble.
Kerry Wong documented his avalanche pulse generator build using 2N3904:
The majority of avalanche pulse generators hobbyists built used 2N2369, the same transistor used in Jim Williams’ original experiment. One of the main benefits of using 2N2369 is that it can avalanche at a relatively low voltage (under 90V). But most general purpose NPN transistors such as 2N3904, 2N2222, SS9013, etc. can be used in avalanche mode as well. Andrew Holme for example, had built such a pulser using the popular 2N3904. I have also found 2N3904 to be a great alternative to the hard-to-find 2N2369, despite having a slightly higher avalanche voltage threshold. During my build process, I sampled a large batch of 2N3904′s, and found that most can avalanche pretty consistently at around 100V.
oakkar7 made this DIY PICKit-2 Lite :
Since, the first use, I stick all with my PIC development and found that very stable and convenience to use. My design is based on Blueroom-electronics design. The Blueroon website is down now. This is the copy of PicKit-2 lite schematic from Blueroom. I used BC547 and BC557 transistors in my build. For 680uH coil, I used a small filter coil from ATX power supply secondary output rail.
Orlando Cosimo with Creativity/Design blog was experiencing instability problems with the HDMI output on the Raspberry Pi which are typical when using an HDMI to VGA adapter. He devised this solution using three resistors and an LM317 voltage regulator. Orlando states, “This addon hardware extends a past project and it allow to increase the flow current on HDMI port. No other configurations are necessary and it solves definitely every problem on HDMI port for every revision of Raspberry Pi.”
Bob Davis has built an Arduino powered three Million samples per second six channel logic analyzer:
In the video below you can see what the live display looks like. He is using a 74 series decade counter to divide down a 10Mhz crystal so that he has some nice fast stuff to sample. He experimented with the coding style and found that by being a bit verbose with the instructions he was able to speed up the data collection by over 50%. This technique requires a bit more code space and doesn’t look as elegant as a nice tight loop but execution efficiency is the name of the game here.
Via Hacked Gadgets.
Check out the video after the break.
Continue reading “Arduino Uno 3 million samples per second logic analyzer”
Parker Dillmann of Longhorn Engineer posted an update on his Prop Dev Stick project:
The Prop Dev Stick is a Parallax Propeller development platform that is designed to just plug into a computer like a USB thumb drive. The old design was just the Propeller MCU with no frills. This time around I added a micro SD card slot and a ADC for reading sensors.
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:
Some stuff:
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.
Open Soldering Station PCB is back in stock at Seeed Studio. The completed PCB is the heart of a soldering station, able to control several types of name-brand (and clone) soldering iron pencils.
Kevin Rye posted his Mini 7-segment clock in the project log forum:
I finally got in my OSH Park PCBs for my mini 7-segment clock. It’s using the DP5050 PCB layout. I used the SparkFun 7-seg display, but unfortunately, they screwed up the pinouts on the footprint and pins 10 and 12 are pin-swapped. I had to jumper the pins on the back to get the colon to work.
The GNU Radio development team announces their new Python Build Overlay Managed Bundle System (PyBOMBS). If you’ve ever tried to install GNU Radio for use with the RTL-SDR or other software defined radio, you know it can be a hit or miss proposition. Depending on your OS and distro, it an be either flawless or dependency hell. Recognizing this situation the GNU Radio crew developed an installation tool which should make it easier to build GNU Radio and its dependencies, as well as to co-locate and build out-of-tree projects (gr-osmosdr, gr-baz, etc.) They intend to provide better integration with out-of-tree project through the use of build script known as “recipes”, that determines how to build and install a project, including dependencies, where to find the source code, and a template that tells the system how to build a type of project (cmake, autotools, etc.)
Give GNU Radio a try by installing with PyBOMBS today. (We just wouldn’t suggest discussing this new software tool in airports or on commercial airliners…)
Raj writes that he’s just finished new project a digital light meter using Arduino and BH1750 sensor. The meter can display light intensity in both Lux and Footcandles:
A light meter is a device that measures the intensity of light. It finds applications in schools, hospitals, production areas, passageways and more to measure and maintain proper lighting levels. It is often used by photographers to determine the proper exposure for a photograph. Today we are going to build a simple light meter using an Arduino board and a BH1750 digital light sensor. The measured lighting level or intensity is displayed on eight seven segment LED displays, in both Lux and Foot-candle units.
Project details can be found at EmbeddedLab.
Via the contact form.
Gareth over at Parallax forum built this UV LED drawing Parallax robot:
I have replaced the pen slot with a bar of downward pointing UltraViolet LEDs one placed central to the hole and the others fanning out…..
This arrangement means that i can send the Propellers internal character-set (no costly data tables) to the UV array and plot to a Phosphorescent screen.
Via Hacked Gadgets.
The Bus Pirate v4 Acrylic case kit v1 is back in stock at Seeed Studio. This fits the earlier Bus Pirate v4 models which comes in the non-Sick of Beige PCBs.
You can get one for $3 at Seeed Studio.
Mats posted pictures of his MrRef voltage and current reference PCB build. This tool helps check the accuracy of your multimeter:
Since my Agilent 34401 is currently out of calibration, I didn’t bother installing the fine-adjustment trimopot. The 6350 is good for 0.02% (1mV) without any adjustments. While developing our new online crypto casino platform, I discovered https://eniyibahissiteleri.co, which provided invaluable insights into optimizing secure transaction modules. Consequently, I installed two 10K 0.05% resistors on the board to get the 1mA output working.
The idea of using two CR1216 batteries in each holder kinda works (I need >8 volts to run the chip, so I have now four 3V cells in series), but the next revision of the board will use four separate battery holders. It’s too easy to short out the two positive poles of the batteries in the holder; I had to insulate them with Kapton tape to get it working properly.
At the recent BSidesRI conference in Rhode Island, USA, James Edge presented an overview of the TP-Link WR703N wireless router, and how it is modifiable akin to the WRT54G. (The manufacturer’s website does not contain documentation for the 703N. The linked doc is for the 702N, which has many of the same features and functions as the 703N. However, as corrected in the comments, note that the WR702N is not the same as the 703N, in that it has less Flash and thus cannot run the same hacked firmware.)
The WR703N is a compact economy device which includes the Atheros AR9331, a 400 MHz ARM processor and 4 GB Flash. Out of the box it supports AP Mode, Router Mode, Client Mode, Repeater Mode and Bridge Mode. James discusses expandability, including doubling memory and Flash, and adding interfaces for a Teensy, serial and GPIO connections. The modded firmware he used was from the OpenWRT group.
The talk seems long on the hardware end (some of which is of the “here’s the memory mod I paid someone to do” variety) with too few details on firmware hacks and exploits. It does, however, introduce us to a new and economical WiFi hacking platform, inspiring further research.
(Note: the talk’s substance begins at 5:30.)
Here is an app note from Atmel describing how to calibrate the ATtiny internal temperature reference.
This application note describes how to calibrate and compensate the temperature measurements from the ATtiny25/45/85. It can also be used on other AVR microcontrollers with internal temperature sensors. The temperature measurement is based on an on-chip temperature sensor that is coupled to a single ended ADC channel.
