Wednesday, November 28, 2012

DIY Surround Sound Dock for Apple iPods and iPhones

This is a "quick design" to make surround sound dock for Apple iPod, iPhone and iPad devices. This audio docking module contains analog surround sound processor, bass booster and electronic mode switch.

Main components of this surround sound dock are LA2610 - analog surround sound processor and ATTiny13 - 8bit MCU. This unit is design to work with 9V external DC power supply and it can deliver maximum of 2 × 1W audio output power.

Printed Circuit Board Design of Surround Sound Dock

In prototyping stage we test this system with couple of Apple iPod and iPad devices with 4inch full range 8Ω speakers. This system can also drive professional headphone through its "Ext. Output" connector. This system need 160mm × 100mm double side PCB and it is specifically design for vertical docking chassis.

This project is an open source hardware project and its design and other related materials are distributed under the terms of Creative Commons - Attribution 3.0 Unported license. Project Firmware source code is distributed under the terms of GNU General Public License 3.0. All the schematics, PCB design and firmware files of this project are available to download at elect.wikispaces.com.

Sunday, November 11, 2012

LASER Based Gate Keeper

These days many verities of alarm systems are available in the market. Some of them get triggered through touch and some type where a wire needs to broken to get triggered.  Both of these types of alarms have some limitations and problems. Wire based alarms are easily avoidable, noticeable and need some regular maintenance. Touch type alarms often pickup RF waves and get activated (because of that it need some controlled environment to function properly).

In this project we design and develop LASER based burglar alarm system. Instead of wire(s) this system use LASER light wave and it can effective for more than 50m. Core features of this alarm system are:

  • High audio output power (Max. 3W PMPO)
  • Master light override switch
  • Inbuilt alarm test functionality
  • Memorized power state
  • Quick response time (aprox. 10ms ~ 30ms)
  • Support for wide input voltage range (15V – 25V DC)
  • Easy to build and calibrate
  • Compact size (aprox. 130 × 200 × 60mm)
This alarm system is specifically design for outdoor use and it is recommended for garages, warehouses, to cover wide range of landscapes, etc. 

LASER Based Gate Keeper - final assembly

The core part of this system is ATMega8 MCU and it handles all the functionality of this system. TDA7267A is a power amplifier and NE555 is used as a secondary audio oscillator. TLC393 is used as a sensor driver and it handle both "master LDR" and "environmental sensor LDR". 

This system use high voltage and handle it with extreme care. Do not touch U1’s (BTA12-600) heatsink or associated parts when the power is ON. Make sure to use proper heatsinks for U1 (BTA12-600), IC1 (L7805) and IC2 (L7812) and for IC6 (TDA7267A). The circuit board should be placed in a suitable container and it does not need any maintenance.

This system is distributed as an open hardware project. All the project schematics, firmware files (including source codes) are available to download at elect.wikispaces.com. This project is covered under the terms of Creative Commons Attribution 3.0 Unported License and firmware source code is release under the terms of GNU GPL 3.0 License.