Digital Voice Record and Playback Project using ISD2560P This project is based on ISD2560P IC which allows us to record 60 seconds voice and playback it with very high quality. As shown in the schematic, we input the voice by using an electret microphone. Controlling the circuit is very simple. Sw1 switches between record and playback modes. Push button B1 is used for start and pause functions. B2 stops the process. DIY 4×22W car audio amplifier based on TDA7384 So this time I decided to make pretty simple but powerful enough audio amplifier. For this I’ve chosen quad bridge car audio amplifier TDA7384 which has four input and four output channels with power capability 4×35W(4Ω). If connect to car battery where operating voltage is about 13.2V, then each channel can give 22W(4Ω). TDA7384 is an AB power amplifier cased in flexiwatt25 package which is designed for high end car radio applications. Full schematics and PCB is inluded. Squaremin - Theremin Style Instrument Theremin Style Instrument: This battery powered electronic musical instrument is a descendant of the theremin and can be played without contact from the musician. This easily - assembled, small instrument contains two infared (IR) sensors, one controlling the note, with the other controlling the octave that is played through the speaker in the front. There are seven possible notes (c-b) and 7 possible octaves of each note. The tone is reflected by one of seven colors that illuminates the center area and highlights a small indicator located on the top panel. The brain of this piece is a boot-loaded atmega chip. The source code is available, as well as, pictures and a video. Check it out here: DIY LED Heart We live in the information age. Your phone knows where you like to eat, computer programs know what movies you like better than you do, and going to a party can mean going in this life, or a Second Life. So why is your message of love still stuck in the 16th century? These days it takes more than a sonnet to melt a girl’s heart. This video tutorial shows step-by-step how to make a Valentine’s Day card for the digital age. The NerdKits team shows how to make an LED Heart Valentine’s card powered by a microcontroller. The heart features an LCD screen for a personalized message, and 20 LEDs around the perimeter that can be programmed to show any pattern. The code provided contains a “twinkle” function that randomizes the process to provide a true star-like twinkle. K-502 Tube amplifier kit Scott Bartlett has put together a fantastic looking tube amplifier. The tube amplifier kit is the popular and inexpensive K-502 tube amp kit. [via] RS232 to SPI Interface This project is a Microchip PIC microcontroller with an RS232 serial interface on one side and an SPI interface on the other. The SPI interface uses the SSP port on a 16F819 device. By sending commands on the RS232 interface it is possible to send any sequence of bytes on the SPI interface from the PIC. These can enable or disable the chip select and read, write or exchange a sequence of bytes. Class A Ultra Linear (UL) 12SL7 SRPP / KT88 SIPP Tube Amp Scalable tube amplifier circuit which will work with a number of octal tubes (KT77, 6CA7, EL34, 6L6GC, KT88, 6550, KT90). Driver stage is an SRPP 12SL7 tubes and the output stage is a Class A UL SIPP with KT88 tubes. LM317HV Regulators are used for the cathode CCS. [HOW TO] Make your own Metronome![[HOW TO] Make your own Metronome](img/79.jpg) Daniel has a great how-to on making your own metronome Reading the data output from cheap digital verniers and scales The circuit make good use of the on-chip comparator in a single 12F675 PIC to detect the low level data and clock signals from the scales. The firmware reads both 24 bit binary and 7 digit BCD output scales types, can switch the scale to fast or slow reading, zero the scale display and outputs the data in an easily readable format at 115,200 Baud. USBGame12 - an Interface for Simple Joysticks This interface offers 12 digital inputs presented to the operating system as USB joystick with 4 directional buttons and 8 general purpose buttons. It can be used to connect historic joysticks or for general purpose digital inputs.This project uses an ATmega8 microcontroller from Atmel. and used the software-only usb driver from Objective Development. |
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