SEP30
Alarm clock with accelerometer and propeller chip
Here is one very interesting alarm clock concept.
This alarm clock has no buttons to turn the alarm on/off yet that doesn't stop you from flipping it off when it starts waking you up in the morning. It is based on Propeller microcontroller, uses GPS receiver for timekeeping and an accelerometer for the user interface.
The very interesting thing about it is that the 7-segment LED display also flips when you turn it upside down so you can still read the current time. Now that's just cool!
Check out the video after the break.
Source: Microcontroller.com
SEP24
All about inductors
Last month we have seen a great tutorial about crystals and oscillators from "The Signal Path" blog and now we can learn about inductors thanks to Afrotech Mods blog.
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
SEP23
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.
Source: Edward
SEP22
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!
Source: Hack-A-Day
SEP21
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.
Source: Hack-A-Week
SEP20
Simple USB temperature probe
This project is based on EasyLogger from Objective Development and is used to log temperature on PC on daily basis.
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
SEP19
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
SEP16
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.
