MAR9
On-board computer for VW Golf Mk2
If you are like me – driving an older car without a fancy board computer showing outside/inside temperatures and other trip info, don't be sad, because now you can build one yourself.
You might say that this one is a bit more techy than those in newer cars because besides showing the standard: time and date, indoor and outdoor temperature, trip time, engine speed (rpm); you get more: cooling water (coolant) temperature, oil temperature, board voltage (V), battery charging current (A) and fuel quantity (in liters). Sensors used in this application are: DS1305 A/D converter, 3x DS18B20 1-wire temperature sensors, DS1305 RTC from Maxim-IC and ACS752-100 100A current sensor from Allegro (just like in this project). Data is processed with ATmega8 and displayed on 1x16 LCD display with backlight.
Source: Erik_G2RP
MAR2
Phone line recorder project published
How many times have you wished that you have recorder your recent telephone conversation? I have, many many times...
So I finally decided to make this happen by using PC and a piece of hardware (powered from USB) to record audio from phone line to MP3 format. I wanted this thing to work automatically, to start recording when any of phones in house is picked-up (line occupied) and stop recording when all phones are hung-up (line free).
FEB26
LED Wave Display
This is a LED Wave Display. When you want to stand out from the crowd, just stick your hand out and wave away. Custom message will be displayed right above your head.
On the other side, this is nothing else but a simple POV system. A few LEDs and a microcontroller together usually do the trick pretty well. In this circuit we also have a simple accelerometer switch, but it is nothing to worry - it is a simple mechanical switch constructed with a little weight mounted on a brass (looks like it) sheet.
I really wonder why no GSM phone manufacturer ever mounted this on the back of a phone for easy cab hailing. Now that's a cool idea for a project!
Source: Csaba Bleuer via HackedGadgets
FEB23
Halogen Bike Light
When choosing a bike light we often go for cheaper LED lighting. Cheap is usually not better, but also expensive doesn't necessarily mean better.
This is an example of how cheap and good it can get when doing it yourself. Requirements: Halogen light bulb for 6V, Atmel ATtiny45, LiPo/LiIon battery pack and a few other electronic components. Because most battery packs provide more than 6V when fully charged which is the maximum for this halogen bulb, ATtiny45 acts as a smart power regulator and keeps voltage of maximum 6V on the bulb.
Let's face it, you simply can't ride a bike at night without a headlamp and this is very cool solution to that problem.
Source: MnM Ringwald
FEB16
Source codes for my PIC projects published
After a little bit of thinking I have decided to go public with source codes for my two projects: Phone Call Alert and SMS Box.
Phone Call Alert (PIC16F84A) is a module that uses PSTN (fixed phone line) to remotely report an alarm condition. SMS Box (PIC16F877A) is a bit more complex and it is used to interface cheap Siemens GSM phones to a microcontroller for sending and receiving SMS messages (and more). I am publishing the source of SMS Box because I don't have any more time to work on it and it needs some improvements (actually just one): to replace my implemented "4-wire bus" with standard SPI bus. Sources are written in MPASM assembly and if someone changes the bus to SPI please let me know!
FEB15
Robot vision with ATmega8 and color camera
AVRcam is an excellent embedded real-time image processing engine and it is well suited for robotics applications.
It is based on Omnivision OV6620 CMOS color image sensor and ATmega8 microcontroller and it is capable of tracking up to 8 colorful objects! The interesting thing is that the firmware occupies only 4 kb of 8 kb available and uses just 692 bytes of RAM for running. First version of AVRcam used 16 MHz crystal for ATmega8 and it was capable of processing 27 images per second. Current version takes 17.7 MHz clock directly from OV6620 module and it can process full 30 images per second. Communication with this module is achieved via standard UART and well designed data protocol.
Aside from robotics applications, this device can be used in security systems for movement detection and alarm triggering.
Source: John O. & Brent T.
FEB5
Vehicle GPS tracking software
There aren't many posts about software on this site but since this is not just "any" software it sure deserves it's introduction here. This is a web portal for displaying maps and tracking information of those tracking devices based on Telit GE863-GPS modules such as EZ863.
Telit modules can be purchased from good old SparkFun but I must say that they don't come cheap. Anyway, this PHP tracking system is written in PHP and it has many features: "Live" view showing one of more vehicles, "History" view allowing display of a specific vehicle's track on a specified date, export of track data via CSV or KML...
Maps used in this system are from Google and the whole project (in PHP) is available for download on the project page.
Source: Nicholas Skinner
FEB4
Digital entry lock with keypad and smart cards
This project is a very secure entry system for your house or some other protected area.
For entry it uses a PIN code in combination with Java Card™ smart card which performs a challenge-response scheme with triple DES encryption (192 bits long keys). It also has internal real-time clock and all entries through this system are dumped via RS232 port to a PC. It is built around a Keil MCB2130 development board but there is also a full schematics for LPC2138 ARM microcontroller so it can work as a stand-alone system.
It sure seems to provide better protection than those high security locks as we can see here.
Source: Carlos Cossio
