The Wireless Inventors Kit for the Raspberry Pi (RasWIK) is an exciting and affordable addition to the Raspberry Pi. RasWIK demonstrates that with our leading edge technology anyone (and we mean anyone) can build wireless sensors and actuators , you do not need huge experience, a degree or even any tools. We show you even how to connect the devices you build to “the Internet of Things” (IoT) service providers such as Xively.
Getting started is just 5 simple steps:
1. Insert the preconfigured SD card to your Pi
2. Plug in the Slice of Radio to the GPIO connector
3. Turn on the Pi
4. Power the XinoRF development board
5. Lauch the Python based example application on your Pi
Thats it!……..you are now past step one of your journey to wireless nirvana
RasWIK – Raspberry Pi Wireless Inventors Kit - [Link]
by Cabe Atwell @ edn.com:
Love it or hate it, there’s no question that Apple’s iPhone line is popular, and while the numbers haven’t officially been announced yet, the company has already broken its record for pre-orders online (roughly 4 million in a 24-hour period compared to the iPhone 5’s 2 million). The new smartphone comes in two flavors — the 6 and the 6 Plus. In this teardown, we focus on Apple’s flagship, the larger “phablet” 6 Plus.
Teardown: Inside the iPhone 6 Plus - [Link]
A fine-spot welder is one of the few equipment where building yourself is cheaper than buying. There are already published a lot of DIY spot welders, this one has some unique features:
It can be used in 2 welding applications: opposed and series configuration.
The construction is kept very simple.
Accurate electrode force adjustment.
It has a solid electrode holder, made of a radiator earthing clamp.
An Arduino microcontroller is used to set the weld time accurately.
Creates a double pulse which improves clamping.
The current can be reduced for welding sensitive parts.
DIY battery tab resistance fine-spot welder - [Link]
by pinomelean @ instructables.com:
Lithium based batteries are a versatile way of storing energy; they have one of the highest energy density and specific energy(360 to 900 kJ/kg) among rechargeable batteries.
The downside is that, unlike capacitors or other kinds of batteries, they can not be charged by a regular power supply. They need to be charged up to a specific voltage and with limited current, otherwise they turn into potential incendiary bombs.
And that’s no joke, storing such a high amount of energy in a small and normally tight packaged device can be really dangerous.
Li-ion battery charging guide - [Link]
A very brief look at the new WENS 540 Debug Meter with Charles from Trio Test at the Electronex show stand:
This is NOT a review, or my normal blog content, it’s just a quick look because some people may be interested in it. So please, no silly complaints.
A combination 10MHz oscilloscope, 50000 count meter, 8 channel logic analyser, data logger, serial protocol analyser, and digital pattern generator.
WENS 540 Handheld 10MHz Oscilloscope and Debug Meter - [Link]
How boost converters work and how to build a 50W adjustable boost converter circuit.
DC-DC Boost converter tutorial - [Link]
by w2aew @ yoututbe.com
Op amp gain-BW product and slew rate limiting are defined, discussed and demonstrated on the bench. This discussion applies to the majority of general purpose op amps on the market – as most op amps are internally compensated with a single dominant pole. High speed op amps, unconditionally stable op amps, non-unity gain stable op amps, high power opamps, etc. may not follow these characteristics because they are often compensated differently in their design. An LM358N is used for the example circuit. Other popular op amps like the LM741, etc. will behave in a similar way. Sometimes the slew rate limit of a device will be the dominant factor in determining the bandwidth, and other times the gain-bandwidth product will determine the resulting frequency response. The video demonstrates why this happens.
Basics of Op Amp Gain Bandwidth Product and Slew Rate Limit - [Link]
We all know lithium-ion batteries need careful monitoring to prevent over-charging and ensure cell temperature remains within limits. We all thought we knew the best way to replace the charge as well: trickle charge, take it nice and gentle to keep the cell temperature down and prolong cell life. Turns out we may have got that last one wrong! New findings published in the Nature Materials Journal by a team of researchers at Stanford University indicate that by tweaking the battery design it may be possible to get faster charge/discharge rates and also increase the number of charge cycles.
Better lithium-ion Charging - [Link]
A press release from the University of Southern California describes a novel transmission technique which can achieve very high data rates. The research led by Alan Willner of the USC Viterbi School of Engineering does not use a single carrier to send information but instead combines independent radio beams using a ‘spiral phase plate’ that twists each radio beam into a unique and orthogonal DNA-like helical shape. The receiver untwists the beams and recovers the different data streams. “Not only is this a way to transmit multiple spatially collocated radio data streams through a single aperture, it is also one of the fastest data transmission via radio waves that has been demonstrated,” Willner said.
Twisted RF beams achieve 32 GB/s - [Link]
Ondřej Karas of DoItWireless writes:
If You are interested in LED driving through RF, this article would be interesting for you. I tested own PCA9634 breakout board for this chip and wrote simple low level driver for IQRF TR-52D module. Next week, I am going to publish PC application for comfortable operation with that.
Wireless LED driver with PCA9634 - [Link]