by Giovanni Militano @ diyaudioprojects.com:
I’ve always enjoyed electronic kits of all kind and like many of you will credit them for the foray into DIY audio. Over time as my DIY skills matured I found myself taking the DIY route for projects far more often than relying on kits. While I will always enjoy electronic kits, I generally won’t try one out unless there is something really unique about the kit. When I saw the Gobo Stereo Audio Amplifier kit from boxedkitamps.com, I was immediately intrigued by the unique looking enclosures available with the amplifier kits. Shown in Photograph 1 below is the completed Gobo Stereo Audio Amplifier kit with a translucent blue acrylic enclosure. The choice of enclosure finishes for the Gobo stereo amplifier kit include blue, dark grey and orange acrylic and bamboo.
Gobo Stereo Audio Amplifier Kit (LM1875, 15W, Class-AB) - [Link]
Main task – advanced communication between multiple Arduinos using I2C bus.
Main problem – most online tutorials covers just one blinking LED with almost no practical use. Slave just executes ONE and SAME function every time Master asks about it. I’d like to outsource slave Arduinos for zillions of tasks.
Proposed solution – simple protocol which enables to send any number of commands to Slave, opposing single return from simple Wire.onRequest();
Simple I2C protocol for advanced communication between Arduinos - [Link]
In this episode Shahriar takes a close look at programming the popular NeoPixel RGB LEDs using a PIC microcontroller and C-language. A close-up of the NeoPixel (WS2812) LED is shown with attention to identifying various semiconductor elements inside the package. The principle operation of the LED is the described along with a detailed explanation of the pins and the one-wire communication protocol.
A simple evaluation board for the PIC18F4550 is used to drive a circular array of 60 NeoPixel LEDs from Adafruit. After presenting the difficulties of providing an accurate pulse-shape using the C-language, the measured waveform is shown on a Tektronix MDO4000B. Finally, the code for a circular color rotating pattern is presented and demoed. The code for the experiment can be downloaded from The Signal Path website.
Tutorial on Programming the NeoPixel (WS2812) RGB LEDs - [Link]
2x UT33 – with a manual and also automatic range selection are ideal “reserve” tool for every workplace.
Majority of us already probably has its own favorite multimeter. However, sometimes it happens, that we need to measure two parameters at once (for example voltage and current) and with one device it´s usually not possible… Even though it´s obvious, that it would be ideal to have two multimeters, you didn´t buy it, because you simply don´t want or can´t invest a considerable amount into another tool (maybe even a “top level” one.
That´s why we have for you a tip how to solve this dilemma. It is the multimeter Uni-Trend UT33 and right in two versions:
Both tools feature an excellent price/ performance ratio. For the price of approx. 8-11 Euro they offer measurement of all common parameters, incl. AC (voltage, UT33A also current). UT33A also measures hFE of transistors, UT33C a temperature by a K probe. In many cases a higher resolution of UT33A (3999) can be very beneficial. Decent accuracy, solid construction and exchangeable measuring leads (not hard-wired to a device, as usually in this price-level) belong to another pluses of this series. Naturally, multimeters UT33 are also suitable as a “main” tool for beginning amateurs and students.
Universal multimeters UT33A and UT33C for a special price - [Link]
These are the RFID readers I used. http://www.parallax.com/product/32390
Arduino RFID Card Door Lock System - [Link]
Rechargeable batteries save us a lot of money but take a lot of time. What if you could recharge a battery in seconds instead of hours?
Rechargeable batteries save us a lot of money these days but for the savings, we give up some of our time, waiting for them to recharge. What if though. What if there was a rechargeable battery that took seconds to recharge instead of hours? That is exactly what I’ve invented and I need your help to bring this to the masses and show the world that we no longer need to waste hours of or lives waiting for a battery to charge.
With the leaps and bounds being made today with capacitors, they’ve gone from being able to store a tiny potential of energy to now, being able to store enough energy to be considered a power source. These high Farad capacitors are known as super capacitors and aside from providing electricity for an extended period of time, they can also be charged very quickly. Recently, there’s been another development, combining the technology of super capacitors with lithium ion batteries. The usually downside to super capacitors from batteries is that they don’t provide electricity for nearly as long. However, with the advent of the lithium ion capacitor, that is quickly changing.
30 Second Charging, Rechargeable Battery - [Link]
This is Part 2 of a series of blogs regarding the development of a wall-mounted server based on the Raspberry Pi, featuring WiFi and a colour touchscreen. Part 1 can be found here.
The enclosure I’m using, a re-purposed room thermostat casing, places some very tight constraints on the dimensions of the Raspberry Pi and PiTFT board.The plastic used in the case is quite sturdy, and is at least 2mm in thickness. Therefore the real inner depth of the case is about 12mm. As for the width of the Pi, we need to shave at least 4mm from the side. The Pi itself is 86mm wide, same with the PiTFT board, so we will need to find a way of making it closer to 82mm.
Pi On The Wall – wall mounted home server - [Link]
by JamecoElectronics @ instructables.com:
Build a DIY geiger counter that uses a PIN photodiode as a substitute for an expensive Geiger-Mueller tube. It detects alpha and beta radiation particles. The circuit is soldered onto a small protoboard and everything is placed in an aluminum enclosure. Copper tubing and a piece of aluminum foil is used to help filter out noise and RF interference.
Pocket Photodiode Geiger Counter - [Link]
Here’s a cool Solar scare mosquito project by Gallactronics. He writes:
So I built a device that generates air bubbles at regular intervals and effectively produces ripples up to a radius of 2 meters (sufficient for most urban water bodies). The device automatically switches on when it comes in contact with water an alarm alerts if the water body dries up or someone tries to remove the device from water. At less than $10, the device is cost effective and being solar powered, it is energy independent and maintenance-free.
Solar scare mosquito - [Link]
by ASCAS @ instructables.com:
Have you ever wanted to broadcast your own radio station within the neighborhood? Ever get curious on where people get those “Surveillance Bugs” from spy and action movies? This small and simple FM transmitter is the toy that geeks have always wanted.
FM transmitters can be complicated to build, that’s why I’m teaching you how to make a foolproof FM transmitter. There’s no need to buy kits, this tutorial includes the PCB layout and the schematics. It has a range of up to 1/4 mile or more. It’s great for room monitoring, baby listening and nature research.
The Ultimate FM Transmitter (Long Range Spybug) - [Link]