Dilshan R Jayakody’s Web Log

The main objective of this project is to create an experimental prototype of a digital potentiometer using Microchip's MCP4141 IC. MCP4141 is available with end-to-end resistances of 5KΩ, 10KΩ, 50kΩ, and 100KΩ. This potentiometer-module can drive MCP4141 with any of the above mention resistances. 3D view of MCP4141 based digital potentiometer PCB To drive the MCP4141, this module use ATtiny13 MCU. This MCU control MCP4141's resistance, based on the rotary-encoder events. ATtiny13 is an 8-pin, low power 8-bit MCU with an internal oscillator. The key reason to pick this MCU is its availability and lower price. Due to a lack of hardware-based SPI, this system use bit-banging SPI implementation to drive the MCP4141 IC. To reduce the board size, this module employs only 3 components. Which including ATtiny13, MCP4141, and rotary-encoder. The dimension of the PCB design given for this module is 26.16mm × 29.72mm. Breadboard wiring diagram This is an open-source har...

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...

In this project we introduce portable microprocessor controlled CW radio beacon. This CW beacon module is capable to transmit maximum of 64 Morse codes repeatedly in 4.433MHz with 9V DC power source. This system consists of CW transmitter, ATtiny13 microcontroller unit and low current voltage regulator. Atmel ATtiny13 microcontroller is used to drive the transmitter and thanks to its internal 64 byte E²PROM, we may be able to change beacon data without altering the system firmware. While at the testing stages we receive this beacon on 10km radius (using Sony ICF-SW7600GR receiver) by using standard telescopic antenna. To get the maximum range it is recommended to use 3m – 4m antenna wire with this transmitter system. At the prototyping /testing stages we try this transmitter successfully with 3.58MHz, 4.43MHz and 6.00MHz crystals. This system is design to work with standard 9V battery (6F22/6LR61). At the prototyping stages we test this system using 12V and 10V DC power sou...