Using a transistor as shown, you can double the allowed voltage limit on a current-sense amplifier by stacking two such amplifiers one upon the other. The voltage signal from the bottom amplifier then represents current as the voltage across the sense resistor, times the product of the gains of the two amplifiers.
Thanks for the tip rsdio!
There’s a new preview for the State of Electronics a documentary about open hardware. The first trailer is here
The producer hopes a network will be interested if there are a lot of youtube views, your extra hit could make it possible.
Interesting fact: filmed with a Canon EOS 5D Mark II digital camera.
Video below.
Continue reading “New State of Electronics documentary trailer”
schazamp posted pictures of an assembled PIC USB LCD backpack PCB in the project log forum. Nice work!
Thanks for posting a picture of the completed board! With our new unlimited free PCB program schazamp gets a coupon code for another free PCB.
Every Friday we give away some extra PCBs via Facebook. The first few people who comment on this at Facebook get a free PCB. More PCBs via Twitter on Tuesday and the blog every Sunday.
This week we’re giving away two USB IR Toy v2 PCBs. Use a remote control with your computer, view infrared signals on a logic analyzer, or capture and replay remote control buttons. USB Infrared Toy v2 has higher-power infrared transmitter and several new features:
Don’t forget there’s free PCBs three times a every week:
Get IR Toy v2 for $22.05 at Seeed Studio, including worldwide shipping.
Continue reading “Free USB Infrared Toy v2 PCB via Facebook comments”
The Altera Max V Development Kit is designed around the MAX V CPLD (5M570Z, 256-pin FBGA, -5 speed). The board features two general-purpose 2×20-pin 0.1-inch expansion headers, a 4-pin PC speaker header, two 6-pin motor control headers, a Type B USB connector (power source and communication port) with cable. The board has footprints for the user to install an I2C serial EEPROM or SPI EEPROM. The kit includes several design examples, and programs via the Quartus® II Web Edition design software.
You can get complete information from Altera’s online documentation.
The Max V dev kit is available for $74.95 from Altera.
Check out this review in Design News.
Don’t forget to share your current project in the comments or the forum.
Here’s a summary of major developments over the last week:
Coming this week:
What are you hacking this week?
SugarAddict believes there’s an Easter egg in the Capacitive Booster pack we mentioned earlier. He writes:
Click the rocket in the middle of the demo program and dial right 4, left 3, right 0, press center.
When you get your Booster Pack, give it a try!
Via Four-Three-Oh!
How many 8-bit and 16-bit computer system fonts do you remember? These two articles look at who was behind them, and what gives early home computing such a distinct feel:
My love of typography originated in the 80′s with the golden years of 8-bit home computing and their 8×8 pixel monospaced fonts on low-resolution displays.
It’s quite easy to find bitmap copies of these fonts and also scalable traced TTF versions but there’s very little discussion about the fonts themselves. Let’s remedy that by firing up some emulators and investigating.
rucalgary modified an Epson printer to print PCBs. The results look good, but the printing process isn’t simple. It requires multiple passes and a heat gun, check out the video after the break.
Thanks McZ!
Haley posted build pictures of the XC9572XL CPLD development board from a free PCB Sunday.
Thanks for posting a picture of the completed board! Under our new unlimited free PCB program Haley received a coupon code for a new free PCB.
Get an assembled XC9572XL development board for $15. A CoolRunner-II dev-board is also available for $15.
Via the forum.
Our favorite tools have a new home on the wiki. Each week we’ll muse about one of them. Have your own tool review? We’ll post that too!
Our photo studio is setup for quick and easy photographs. It’s on a table right next to a computer in the development area so we can do demos without dragging out a laptop. USB, serial, network, and power cables are tied to the table legs and ready to go.
For reflection-free photos we use a cheap light tent with a nice piece of watercolor paper as the background. Two halogen lights came with the light tent, but the bulbs leave photos with a yellow or pink hue. You might notice that in our pictures, especially older photos. Better lighting is a high priority.
Several small tools always come in handy. A toothbrush and canned air are great for blasting away a spec of dust from an otherwise perfect shot. Sticky tack is great for posing a scene, we use it to hold boards and cables in place. One thing we’re sorely missing is a tripod to hold PCBs upright and square for photos.
We use close-up pictures all the time to show a schematic next to actual parts. For a long time we used a simple point-and-shoot digital camera in macro (flower) mode. Few of the shots turned out, so we took a bunch every time and hoped for the best. Usually it took two or more reshoots to get an in-focus picture without dust or reflections, and each time we had to move the SD card and reset the camera. It was super annoying, so we started looking for something better.
In 2011 we moved to a Cannon EOS 500D. Our only criteria, besides price, was some kind of live preview over USB. This was the only camera in our price range that clearly listed that feature. The picture quality is more than adequate for 500pixel web shots.
The PC interface is bubbly, annoying, and hard to configure, but it is functional. Live preview is good for coarse adjustments. Is has a helpful alignment grid, the focal point can be set with a mouse clock, and an eye-dropper sets a custom white level. Test shots show what to expect in the final picture, this is where we catch any dust, color, or reflection problems. Final shots are copied to the PC and display immediately. Gripes about the software aside, this setup is exactly what we wanted. It saves a bunch of time, and we never have to swap SD cards.
There are a couple upgrades we plan to make. Better lighting is the first priority, something with a good white color. Aligning the boards with the camera is a pain. A stand to hold boards upright, or a camera tripod that faces down, is also a high on the to-do list. The camera lens has a minimum 10 inch focus distance, and expensive macro lens would let us get in closer but probably isn’t worth the extra cost.
Adafruit has a great photography tutorial, don’t forget to check it out.
There’s more tools too.
The Atmel QTouch Library is a royalty-free software library (GCC and IAR™) for developing touch applications on standard Atmel AT91SAM and AVR microcontrollers. Developers can use it to integrate touch-sensing capability into their applications by linking the library into firmware. The library can be used to develop single-chip solutions for many control applications or to reduce chip count in more complex applications.
You can download the library here.
To celebrate the launch of USB IR Toy v2 we’re giving away 3 PCBs. Get a PCB on Twitter, one on Facebook, and one on the blog. Just be the first to comment or retweet this post.
Use a remote control with your computer, view infrared signals on a logic analyzer, or capture and replay remote control buttons. USB Infrared Toy v2 has higher-power infrared transmitter and several new features:
NEW: pick your free PCB from the Dangerous Prototype free PCB drawer. You now receive a coupon code for 1 PCB with free shipping. You can choose this PCB, or another PCB if you prefer. More about the free PCB drawer.
Don’t forget there’s free PCBs three times a every week:
Get IR Toy v2 for $22.05 at Seeed Studio, including worldwide shipping.
Continue reading “Free USB Infrared Toy v2 PCB via blog, Facebook, Twitter RT”
Open Sesame on Prezi
dop3j0e needed a way to recover the password on his ThinkPad’s hard drive after the laptop’s fingerprint scanner died (in which the password was stored.) Luckily, the drive’s IDE had 16 5V data lines just like the inputs on the OpenBench Logic Sniffer. He wired the Logic Sniffer to the lines and watched the data using Sump. In no time he was able to find the password, unlock the drive, and permanently remove the password.
For all the good details check out the above slide/video presentation (note that you need to click on the “right arrow” to advance to the next slide, as this is not a continuous video.)
Rubu (via the contact form) points out this link to a written explanation of the process.
Get your own Logic Sniffer for $50, with free worldwide shipping.
Via Hack A Day.
Use a remote control with your computer, view infrared signals on a logic analyzer, or capture and replay remote control buttons. USB Infrared Toy v2 has higher-power infrared transmitter and several new features.
Read the full design documentation.
USB Infrared Toy v2.0 has arrived. Read the full design documentation.
There’s lots of interesting infrared projects on the web. Serial port infrared PC remote control decoders have been popular for years, Ian published a USB version at Hack a Day. The TV-B-Gone is a popular kit that turns most TVs off by transmitting POWER codes with infrared LEDs. The IR Toy combines all these projects into an upgradable USB dongle, with some extra functions, like a simple logic analyzer that visualizes remote control signals.
IR Toy v2 has three updates that were not in the original hardware:
The added cost of new parts, and the increased cost of PIC 18F2550 chips, made v2 about $2 more expensive than v1.
IR Toy v2 overview:
Infrared frequency detector
While 36-38kHz is the most common frequency for remote controls, some operate at 56kHz, or even more exotic frequencies. The new infrared frequency detector (RX2) measures raw infrared signals.
The extra sensor data can be used to measure the carrier frequency. It might even be possible to record signals in frequency ranges that don’t work with the 38kHz demodulator.
Infrared transmitter
IR Toy v2 uses a new constant current driver circuit to give the transmitter LED more power. It’s way better than the single resistor in the older IR Toy designs. The LEDs get a constant 100mA no matter the supply voltage. The USB power supply varies between 4.5 and 5.5volts, the new design ensures maximum current at all voltages.
More importantly, we don’t rely on a huge current limiting resistor. Previous designs burned excess current in the typical LED current limiting resistor circuit. The resistor needs a minimum power rating of 0.34watts for 100mA IR LED, way out of the range of common surface mount resistors (<0.125watts). The constant current driver doesn’t rely on the current limiting resistor nearly as much. High currents are possible using standard SMD parts, but just in case we used a beefy 1206 resistor.
Breakout area
Unused pins and the main IR signals are brought to a breakout area. Digital and analog pins are available for experimenting.
Resources
Get IR Toy v2 for $19.50 at Seeed Studio. Worldwide shipping is only $2.85 more.
uPOV is a persistence of vision device with an accelerometer. This is the same concept we’re trying for with the USB POV Toy.
The problem I had with most of the current POV units is that they required skill to use effectively, timing your swings so that the message only goes in the one direction, appears in approximately the same spot, etc… So I decided to use an accelerometer in my design!
Check out a video after the break.
Thanks MichaelZ!
Continue reading “uPOV persistence of vision with an accelerometer”
octal started a writes:
I wanted to know what PCB house do you use to make your PCB, your opinion about them and (very important) the time it takes to get your PCBs?
I’m going to send first batch to Seeedstudio (for their proto service) but want to know if you got better and quicker results in other places.
What companies have you tried?
Kelvin writes to inform us about this DE0 Nano Giveaway. Terasic is running a contest from now through May 12, 2011, to select three winnners of a DE0 Nano FPGA board from all entrants who answer the question, “What would you do with a DE0 Nano?” So go to the Terasic site and post your answer there.
The DE0-Nano board introduces a compact-sized FPGA development platform suited for prototyping circuit designs such as robots and “portable” projects. The board is designed to be used in the simplest possible implementation targeting the Cyclone IV device up to 22,320 LEs.
Via the contact form.
We’re all familiar with CPLD and FPGA. Now Tabula, Inc., has debuted their line of 3PLD chips. Known as the ABAX product family and presently targeted primarily at communications equipment vendors, the chips are said to employ an innovative architecture called Spacetime that enables the devices to achieve superior density and capability for logic, memory, and signal processing.
For more info, check out their documentation page.
The dev kit is available, for $7,500.
So now you know…
There’s a new quick start guide for the MAX 3000A and 7000A CPLDs on the wiki. It’s a work in progress, we could use help and tips from anyone who has worked with these devices.
