This instructable shows how to modify a pair of speakers to also pulse an LED (or multiple leds, you choice) to the beat.
Sound reactive led - [Link]
Another successful high altitude balloon flight with some gorgeous images. Alexei writes:
High altitude ballooning is an emerging hobby, since the price of GPS and communications equipment has gotten quite low. It is an excellent hobby for people fascinated by space flight and telerobotics and has many learning aspects — from systems design to electronics design to software engineering. There is also an exciting risk factor, namely, that you could lose your precious electronics if something malfunctions. In this project, many of my interest and knowledge areas came together. Also, I have verified that the Earth is indeed round and that space is black.
HALO2 High Altitude Balloon - [Link]
Here’s a good tutorial on making your own PCBs (Printed circuit boards). And below is our round up with the many other methods -
Creating Printed Circuit Boards (PCBs) is easy and fun for the whole family! But read the disclaimer — heat and corrosive chemicals are dangerous After you’ve prototyped and tested your circuit design, creating a PCB will provide a sturdy and reliable backbone for your circuit and will give your project a professional finished quality.
Using PCBs can even help reduce the time you spend building circuits, especially if you are producing multiple units, as you only need to follow a parts placement diagram (there’s no longer any need to worry about specific interconnections).
As is usually the case, there is more than one way to do it: there are numerous ways to create PCBs. They range from the time-consumming and difficult to the fully automated and expensive. Here we will attempt to describe a method we’ve found ideal for small production runs (say, a few prototypes to a couple of dozen–when you reach the hundreds, it will probably be easier, quicker and cheaper to outsource) of single- or double-sided boards.
Make Printed circuit boards – An illustrated guide - [Link]
Jmengel shows another way to make two-sided PCBs at home -
This instructable assumes that you know how to generate a layout file using Eagle PCB or similar layout program. I use the toner transfer method of making PCB’s (printed circuit boards) much like many others. The basic idea is to use a glossy paper, print the PCB design on the paper using a laser printer, and to use a hot iron to transfer the toner to the copper. I use the glossy paper that they have behind the counter at Kinko’s. Go to Kinko’s and ask for some sheets of their glossy laser paper, which is really cheap (about 5 cents a sheet). Some people advocate using glossy inkjet photo paper, but I think this is a waste and the cheap glossy laser paper comes off easier.
Anyway, once you have your design and paper, you will need to print the design. The key here is to mirror the top layer so that it will come out correct once transferred to the copper board. It can also help to include alignment marks (the T shaped things in the pic) beyond the edge of your PCB to help you align the two layers.
Two sided PCB using toner method - [Link]
Westfw writes – “In a previous Instructable, I provided an intro to schematic entry using CadSoft’s EAGLE editor.
In this instructable, we’ll make a printed circuit board from that schematic. I guess I should say that we’ll make a PCB DESIGN; making the physical board is a different task, and there are a lot of tutorials on the net (and even some instructables) on making the board after you have the design.”
Turn your EAGLE schematic into a PCB - [Link]
This simple method lets you make LCD backlight of any color and size to bring new look to an old device. For this job you’ll need piece of transparent plastic, LEDs, resistors and some wire plus good set of different tools and couple of straight hands
DIY LCD backlight - [Link]
VU (Voltage Unit) meters are often included in analog audio equipments to display a signal level in Visual Units. We are building a mono input VU meter in this project. You can build one more to use them in stereo mode. Input sensitivity is about 1 Volt rms, up to +6dB. You can adjust the amplitude of the input by using the multiturn 50k linear potentiometer (POT1).
10 LED VU Meter Project by LM3915 and LM324 - [Link]
Probably everybody gets confused each time when considering what connectors to use in electronic projects. There are so many connector types and technologies that can be chosen. So what connectors is the best choice, or there is no single answer? Before answer these questions lets go through several points. First of all why do we need connectors? There is no problem to solder all components and wires together without ability to loosen or wear out. But in fact there are much more advantages of using connectors comparing to reliability of connection.
Connection sockets and headers used in embedded projects - [Link]
The Internet Plug is a web-enabled appliance. The main goal is to show a simple and effective application for home use. The concept is extremely simple: An interface between the cyber world and the real world. A box connected to both of these worlds accomplishes this. The implementation is as simple as the concept, a plastic box with a 3 Power outlets and a computer network connection. The three outlets are for general use, any device can be connected, a lamp, a radio, a TV or any other electrical appliance. On the network connection a simple computer or the Internet can be attached. The Box does the rest, actually the box contain a web server and the power command elements necessary to turn on and off the power to the three sockets.
The Internet Plug II - [Link]
The intent of this project was to build a software DTMF decoder which is run on PIC microcontroller. No any external decoder IC is needed only few external components. DTMF control is convenient where phone line is present, as device can share it with other phone devices.
In this particular project remote receiver can control 4 outputs that can drive up to 10Amps at 12VAC. Device accept three commands: SET, RESET and Check output status. Controller is password protected. All values including password are stored in EEPROM memory. Probably most interesting part in this project is software DTMF decoding as this task is usually done by DSP or specialized chips. Decoding is based on Goertzel algorithm. So here is some challenging ASM coding done, but results are positive. Check out the ASM source. [via]
A software based DTMF Remote control - [Link]