Kenneth was curious about Phase Locked Loops so he decided to dive into them. PLLs generate an output signal that is phase-synchronized to an input signal. They are widely used in telecommunication, radio, and computer systems. One place we commonly find PLLs is the frequency multiplier circuit inside microcontrollers. [via]
The inevitable next step was to break out the breadboard, put together a simple PLL, and just play with it some to try and really get the concept. Luckily, the classic 4000 logic series includes the 4046 PLL chip, which includes both a voltage controlled oscillator and both types of phase detectors. After putting it all together, I figured I’d record a video and let you enjoy the play-by-play as I try and break it all down for you.
A basic introduction to Phase Locked Loops – [Link]
Sebastian would like to build a high-res 3D printer, and to this end he needs a precise way to ascertain the exact positions of various moving parts. Instead of buying an expensive stepper motors he decided to build a magnetic rotary sensor with which he could calculate the distance traveled. By placing a neodymium magnet on the sniping shaft above the AS5043 IC, he should be able to have a rotary encoder with 0.35° steps. [via]
The setup for this sensor is rather simple, you need a few external components and a neodym magnet that is attached to your motors axis. Then you place the sensor under it.
DIY Magnetic rotary encoder with AS5043 – [Link]
Carl found out a way you could use TI’s Code Composer Studio IDE for free. Normally it only has a 30day evaluation period after which you have to pay $495 for the license. But by activating the Free limited license you are able to fully use it as long as you have a XDS100 based JTAG debugger, which almost all development boards for LM3s have. [via]
A quick look at the product page shows you can get a 30 day evaluation version but otherwise you will need to spend $495 per seat. Well that is unless you have a XDS100 based jtag which almost all TI’s LM3S dev kits come with! You simply activate the “Free Limited License” it’s only limit is that it will only work with XDS100 jtags, so no code or time limit.
Using Ti’s Code Composer Studio IDE for free – [Link]
Using constant current to drive LEDs is a good practice, but turning them on instantly can be dangerous for both the LED and the LED driver. Harmful spikes are generated when large currents are instantaneously turned on. This app note from Maxim describes how to soft start LEDs to increase overall lifetime and performance. [via]
An incandescent bulb requires some time to reach full brightness after you switch it on, and that delay gives the eye a comfortable interval for adjusting to the bright light. LED-based lights lack this property. Instead, their brightness goes from zero to 100% almost instantly. That property is welcome in a camera flash, but rather annoying for general lighting.
App note: Soft-Start in LED lighting – [Link]
If you often work with batteries and SMT transistors, then the new UT132B multimeter is the right choice for you.
Into our offer we incorporated the new UT132B multimeter – a “brother” of the UT132D, type, which we have introduced to you recently. UT132B provides practically the same functions, including possibility to measure hfe of SMT transistors , NPN and PNP types in a SOT-23 package, by means of a special adapter. The difference between these two instruments is, that UT132B features measuring of 1.5V and 9V batteries status. That´s why it is ideal for everyone, who needs to simply and quickly judge status of batteries. Measuring of 1.5V batteries is proceeded at a 15 Ohms load and measuring of 9V batteries at a 1 kOhm load. The instrument has a HOLD function and a main switch, thus it is not necessary to turn a measuring ranges switch to switch off the device. Similarly like UT132D, also UT132B is very reliably and comfortably held in a hand thanks to compact dimensions and an ergonomic shape.
The new UNI-T multimeter even for testing of batteries – [Link]
Ninja Blocks are simple but powerful open source hardware backed by an amazing web service called Ninja Cloud that allows your Ninja Block to talk to your favorite web apps.
Each Ninja Block comes with an RGB LED and built-in temperature sensor and accelerometer. Four expansion ports and a regular USB port allow you to add further inputs and outputs.
Ninja Cloud allows you to control your Ninja Blocks without writing a single line of code.
NinjaBlocks – Open Source Hardware for the Internet of Things – [Link]
Over at Blondihacks, Quinn’s written up a really thorough post about etching your own PCBs, building on what she discussed in past documentation. There are a lot of tutorials out there about etching PCBs, but this is probably one of the most complete I’ve seen, particularly if you’re still getting to know Eagle.
PCB Layout and Etching Tips and Tricks – [Link]
MinION – $900 usb-powered DNA sequencer on sale this year – [via]
Oxford Nanopore (ON) has been developing a disruptive nanopore-based technology for sequencing DNA, RNA, proteins, and other long-chain molecules since its birth in 2005. The company has just that within the next 6-9 months it will bring to market a fast, portable, and disposable protein sequencer that will democratize sequencing by eliminating large capital costs associated with equipment required to enter the field.
MinION – $900 usb-powered DNA sequencer – [Link]
Sony’s SmartTags could change phone habits @ Crave – CNET – [via]
Near field communication (NFC) technology enables smartphones to work with mobile payments and public transit systems, but a new accessory from Sony could make the wireless wonder much more personal.
SmartTags are small programmable tokens that give your NFC-equipped Android phone a series of commands to keep you from performing repetitive tasks.
For example, swiping your phone by a SmartTag placed on a nightstand could turn your phone silent, turn off Wi-Fi/Bluetooth, and activate your alarm for the following morning. While the aforementioned tasks are easy to do on your own, perhaps there is a certain charm in an automatic trigger.
“SmartTags” could change phone habits – [Link]
Whoa! See that little bump in the middle of the micrograph? THAT’S A TRANSISTOR. From Ars Technica: [via]
a group of researchers has fabricated a single-atom transistor by introducing one phosphorous atom into a silicon lattice. Through the use of a scanning tunnelling microscope (STM) and hydrogen-resist lithography, Martin Fuechsle et al. placed the phosphorous atom precisely between very thin silicon leads, allowing them to measure its electrical behavior. The results show clearly that we can read both the quantum transitions within the phosphorous atom and its transistor behavior. No smaller solid-state devices are possible, so systems of this type reveal the limit of Moore’s law—the prediction about the miniaturization of technology—while pointing toward solid-state quantum computing devices.
A Transistor From a Single Atom – [Link]