by Annikken @ instructables.com:
This waveform generator is based on the work by Amanda Ghassaei. Waveform generators (or function generators) are used for testing and debugging circuits. e.g. frequency response of op amp or sensors. This waveform generator is powered by Arduino with Annikken Andee shield – a device that lets users create iOS/Android interfaces without iOS or Android programming at all. It outputs sine, triangle, saw and square waves. Frequency is controlled by means of a slider (on iOS/Android device) and wave type is selected using on screen iOS/Android button. With a iOS/Android interface, you can add certain features not possible with hardware buttons. E.g. displaying different ranges of frequencies for each wave type, displaying meaningful controls for certain wave types. For example, the pulse width modulation slider is only visible for square wave types, its not visible for sine, triangle or saw wave forms.
IOS-Controlled Arduino waveform generator - [Link]
by intensePancake @ instructables.com:
In recent years, portable sensor devices have gained a lot of popularity due to their ability to give you instant, accurate information about your local environment. Some of these devices include the Sensordrone, Smart Citizen, and the Storm Tag. These devices combine portability and accessibility in such a way that they’re easy to use and convenient to carry around. However, they can be expensive, as they’re required to pack quite a bit of advanced technology into a very small package.
This Instructable is for my Bluetooth Low Energy Go-Anywhere Sensor Pack (BLEGASP, if you will). It’s a device that I built from an Arduino and various environment sensors. Since environmental concerns differ from person to person, I wanted to create a device that maximizes sensor modularity.
Bluetooth LE Go-Anywhere Sensor Pack - [Link]
Graphic showing the GPIO pin breakout on the Raspberry Pi B+ board.
Raspberry Pi B+ GPIO 40 Pin Block Pinout - [Link]
JColvin91 @ instructables.com writes:
I recently got a collection of soldering iron tips and realized that many people (including myself) might not know what the different tips are used for. After all, for a long time I was under the impression that there was only about three different types of soldering tips and only one useful type of tip.
While I still only use two different types of tips (an improvement), I am much more familiar and confident in using whatever soldering iron tip I may happen to find on the iron. Please know that is far from a comprehensive list of all the different types of soldering tips available, but rather a small handful that I am personally prone to use.
Uses of Different Soldering Iron Tips - [Link]
By Ben Coxworth @ gizmag.com:
Ever since the Fukushima nuclear reactor disaster, there has understandably been an upsurge in the sale of consumer radiation-detecting devices. Most of these gadgets are variations on the Geiger counter, in that they alert the user to the presence and level of radiation, but not the type of radiation – which is very important to know. Researchers at Oregon State University are hoping to address that situation, with the MiniSpec. Currently in development, the handheld device will additionally tell its users what type of radionuclide is creating the radiation, and whether it poses a risk.
Small, portable and cheap radiation detector is being designed for the public - [Link]
by sajjad Haidar @ edn.com:
Power supplies with adjustable DC output ranging from 0V to 30V or 60V are on the market. Above 60V, there are not many. This Design Idea offers a solution.
There are many fixed voltage switching mode power supplies (SMPS) available, and connecting several in series can give us a higher fixed voltage. To obtain an adjustable output either from a SMPS or conventional transformer based supply, one needs to use a linear regulator or a switched mode buck converter. For a buck converter, a MOSFET or an IGBT can be used as a switching element.
Usually, for a high side switch, an IC with bootsrap operation or a pulse transformer is used. There are few photovoltaic couplers available to drive MOSFETs. As they do not provide much current to charge the gate capacitance quickly, these photovoltaic couplers are mainly used to drive low frequency MOSFET switches, such as solid state relays.
Variable HV power supply employs photovoltaic optocoupler - [Link]
PocketScan Leverages Dacuda’s Computer Vision and Robic Algorithm Technology to Deliver a Portable, Versatile, Software and Device Compatible Scanner
ZURICH, Switzerland – Dacuda, a Swiss startup specialized in image digitalization technology, today announced the launch ofPocketScan, the worlds first wireless scanner. The scanner leverages Dacuda’s patented computer vision and robotic algorithm technology to deliver a portable, versatile scanner that’s software and device compatible.
PocketScan provides a user-friendly experience that enables users to scan any format up to A2 fit, scanning items that don’t fit into a regular scanner. By simply moving PocketScan across a document, the content is assembled in real-time and transformed into editable text, tables or images. Tables are transformed into Excel-Sheets and Documents can be edited right away in the typical Word format. Additionally the scanner’s clever design works in any light condition and produces high quality images that are clear, consistent and bright. Read the rest of this entry »
Energy is transmitted in different ways and one of these ways is electricity. It can appear in many forms and through various phenomena such as lightening or electromagnetic induction, and can be used in transport, electrical appliances, and in the residential and industrial sector, to name but a few examples. Physical magnitudes are derived from electricity such as the electric field, current, and electric potential. The latter two are measured in amps and volts respectively.
In order to measure the previous magnitudes and many others, ingenious devices have been developed, called multimeters, which are the perfect example of the high integrity and versatility of the most modern measuring instruments. They are powerful devices, small in size, but large in their ability to detect and solve electrical failures, measure a large variety of parameters such as current, voltage, capacity, resistance, and they are also equipped with additional functions which allow them to measure temperature, continuity, frequency, carry out diode tests or perform as an oscilloscope. Many multimeters have a USB port and have wireless transfer capacity (Bluetooth), which means that the measurement results can be sent to a PC or computer for later analysis. In addition, many of them are designed in such a way that their screen is removable, so that they can operate in difficult to access areas. Read the rest of this entry »
by Henrik’s Blog @ hforsten.com:
In my previous post I wrote about a circuit that would change it’s output depending on what was the spice simulations DC sweep range. Today I investigated the circuit a little and I was able to remove lots of components that didn’t affect the bug and this is the resulting circuit.
Metastable transistor circuit - [Link]
An old but interesting app note (PDF) from Microsemi on resistorless current-sensing technique. [via]
This application note introduces a simple current-sense technique that eliminates that sense resistor, resulting in system-cost reduction, PCB space saving, and power efficiency improvement. Furthermore, the new current sensing mechanism allows higher dynamic tripping current than the static one (built-in low-pass filtering) to improve current-sense noise immunity.
A simple current-sense technique eliminating a sense resistor - [Link]