All about inductors
Inductors are kind of similar to capacitors in a way that they also store energy for later use. The major difference is that inductors store energy in magnetic field and capacitors store energy in an electric field. We could also say that capacitor stores voltage and inductor stores current.
So, here is a great four-part tutorial about inductors where [Afroman] explains all about inductors.
Source: Afrotech Mods
ADS-B Receiver to track aircrafts
ADS-B (Automatic Dependent Surveillance-Broadcast) is NextGen's surveillance technology for tracking aircrafts and from 2020 all plains should be equipped with this technology. Data transmitted over this system consists of many parameters such as aircraft's current speed, GPS position and more.
The interesting thing about this system is that data begin transmitter over it (at 1090 MHz) is not encrypted.
So, here is a project that will receive and decode ADS-B data and plot it on PC. It uses RF tuner from an old analog satellite receiver and ATmega48 to do the work. Schematics and microcontroller firmware is available for download on project page.
Cadsoft Eagle Tutorial series - video
Hack-A-Day team has been working hard on their Cadsoft Eagle Tutorial series and now it is finally finished.
There are four video tutorials in total and they go through schematics creation, custom parts creation, CAM processor and finally PCB drawing.
Be sure to check out all four videos if you are new to Eagle!
Wireless voltage detector circuit
This is one extremely simple wireless voltage detector circuit.
Although it is probably not very smart to use it as voltage probe it can still be used to detect high voltage presence in wires and also as a touch operated switch. The LED can be replaced with a relay to turn on and off some device (but only while there is something to detect). The circuit is very simple and it consists of only 3 transistors, 3 resistors, 1 LED and a 9V battery. This is actually a high gain Darlington transistor and the probe is a small piece of copper or a wire that will detect almost anything.
Check out the video after the break.
Simple USB temperature probe
It is based on Atmel AVR ATtiny45 microcontroller and AVR USB library, also from Objective Development. The temperature sensor used here is LM34 which is an analog precision integrated-circuit temperature sensor, whose output voltage is linearly proportional to the Fahrenheit temperature. There is also a Celsius version LM35 that can be used instead. Source code and schematics is available for download on the project page.
Source: Dan Stahlke
AHRS Sensor Board and RGB LED Matrix
Here is another great tutorial from The Signal Path Blog. Now [Shahriar] does a great intro into two SparkFun's products: 9 degrees of freedom AHRS Sensor Board and an RGB LED Matrix Display which is serially controlled.
AHRS (Acceleration Heading Reference System) Sensor Board is a PCB with multiple sensors: a three axes accelerometer that measures linear acceleration, a gyroscope that measures angular acceleration and magnetometer for heading information. Another product review is of serially controlled RGB LED Matrix Display. You can see the video after the break and download source code for both demos at the "source" link under the video.
Source: The Signal Path Blog
LC meter with PIC16F628A and Li-Ion battery
I needed a good LC meter for my one of my next projects so I went and built the famous LC meter by Phil Rice.
This LC meter design is pretty old but since it is a perfectly good device there was no need to design/build/debug one of my own. So, I decided to change the original design a bit and now it incorporates Lithium-Ion battery, TPS61222 5V power bosster and MAX1811 battery charger.
Arduino LC Meter
After that very popular LC meter based on Microchip PIC16F84 or PIC16F628 we now have a version which uses Atmel AVR ATmega8 microcontroller.
Unlike that popular PIC version, this LC meter can also measure capacitance of electrolytic capacitors. Measuring range is 1pF-10uF for regular capacitors, 10uF-100mF for electrolytic and 1nH-1H for inductors. Display is from Nokia 3310 phone and complete schematics, manual and source code for Arduino is available on project page.
Source: iTeadStudio iStore