Alarms and security related schematics

• Proximity alarm
  

• Electronic lock
  

• Electronic door codelock (PIC16F84)
  

• Moisture alarm
  

• Fridge door alarm
  

• Ultrasonic remote control & alarm system
  

• Wire loop alarm
  

• Digital entry lock
  

• Proximity switch
  

• Toxic Gas Detector
  

• Door knob alarm (PDF)
  

• Water seepage alarm (PDF)
  

• Micro-power over temperature alarm (PDF)
  

• Personal silent alarm system
  

• Active IR motion detector
  

• Frost alarm
  

• Ultrasonic radar alarm
  

• Refrigerator door alarm
  

• Emergency Light & Alarm
  

• Electronic combination lock
  

• Proximity detector for humans / living creatures using eddy current detection
  

• A Basic RF Transmitter for PIR Sensors
  

• PIR motion detector
  

• Simple alarm system
  

• Home security project
  

• 5 Zone alarm circuit
  

• Miniature loop alarm
  

• Novel Buzzer
  

• Gate alarm circuit
  

• Modular Burglar Alarm
  

• Motorcycle alarm
  

• Enhanced 5 Digit Alarm Keypad
  

• Enhanced 4 Digit Alarm Keypad
  

• RF Alarm
  

• Single Zone Alarm
  

• Water Activated Alarm
  

• Water level alarm
  

• Perimeter monitor
  

• Digital combination lock
  

• Alarm control keypad
  

• Almost Ultrasonic Motion Sensor
  

• Touch activated alarm system
  

• Combination Lock (PIC16F84)
  

• Low power RFID transponder
  

Audio power amplifier schematics

• Two transistor audio amplifier
  

• Personal stereo audio amp
  

• Headphone amplifier
  

• 1.5W Audio amplifier
  

• Low-level audio amp
  

• 10W amplifier
  

• 80W amplifier
  

• LM383 12V Amplifier
  

• 18W Audio amplifier
  

• 25W MOSFET amplifier
  

• Headphone amplifier
  

• Portable headphone amplifier
  

• 2W amplifier
  

• 4W amplifier
  

• 8 watt audio amp
  

• 20W Amplifier
  

• 50W Amplifier
  

• 100W RMS Amplifier
  

• 2-Channel Power Amplifier
  

• 25W MOSFET audio amplifier
  

• 50W audio amplifier using ICL8063
  

• Amplified ear for surveillance
  

• 20dB VHF Amplifier
  

• 30 watt FM linear amplifier
  

• Linear FM 50 watt amplifier with BLY90
  

• 60W RF linear amplifier using IRF840
  

• Push-Pull Class A Amp using type 5687 dual triodes
  

• Push-Pull Class A 2A3 Stereo Amp
  

• Single Ended Class A2 SV811-10 Stereo Amp
  

• Audio amplifier output relay delay
  

• Spatial Distortion Reduction Headphone Amp
  

• HeadBanger Headphone Amp
  

• 2W Amplifier
  

• TDA2030 8 Watt amplifier
  

• Headphone monitor amp
  

• 50W audio power amplifier
  

• Bi-Directional 2.4 GHz One Watt Amplifier
  

• Bi-Directional 900Mhz One Watt Amplifier
  

• 20 Watt GaAaFET Power on 2.3 GHz
  

• 1 Watt 2.3 GHz RF Amplifier Using a MRF2001
  

• 2.3 GHz Power Amplifiers
  

• 2304 and 3456 MHz Power Amplifiers
  

• High quality exponential VCA
  

• 16 Watt amplifier
  

• 8 Watt amplifier
  

• Power amp schematic (PDF)
  

• 20 Watt Class-A Power Amplifier
  

• El-Cheapo - A Really Simple Power Amplifier
  

• Single Chip 50 Watt / 8 Ohm Power Amplifier
  

• Hi-Fi Headphone Amplifier
  

• 100W Guitar Amplifier
  

• Death of Zen (DoZ) - A New Class-A Power Amp
  

• Soft-Start Circuit For Power Amps
  

• Thermo-Fan To Keep Your Amp Cool
  

• Audio Amp Output Power Limiter
  

• 55W (Originally 75W) Power Amplifier
  

• 300W Subwoofer Power Amplifier
  

• 20 Watt / Channel Stereo Power Amplifier
  

• Mini bench amplifier (LM386)
  

• 12 Watt Valve Guitar Amp
  

Audio preamp circuits

• Microphone amplifier
  

• RIAA phono amplifier
  

• Low impedance microphone amplifier
  

• Phono preamp
  

• Masthead preamp
  

• Preamplifier for microphone or guitar use
  

• Simple microphone preamplifier
  

• Tube microphone preamp
  

• Simple Stereo Electret Microphone Preamplifier
  

• Simple Stereo Electret Microphone Preamplifier
  

• Phono Preamp
  

• Simple microphone preamplifier
  

• ECM Mic preamp
  

• Hi Fi preamp
  

• Balanced microphone preamp
  

• Electret mic amplifier
  

• Audio preamplifier
  

• Vacuum Tube Microphone Preamp
  

• FET Preamp Cable
  

• Audio preamp
  

Automative, car and motorcycle schematics

• Electronic auto stethoscope
  

• Turn signal alarm
  

• Motorcycle turn-signal system
  

• Cigarette lighter 9V adaptor
  

• Analog Tachometer for Gasoline Engines
  

• Headlight On reminder with Light
  

• Adaptive Windscreen Wiper Control
  

• Car clock
  

• Car message display
  

• Car interval wiper
  

• Safety indicator light
  

• Speed limit alert
  

• Grand Cherokee Off-Highway Lights
  

• Engine control unit schematics
  

• Portable CD Player Adapter For Car
  

• Car battery charger
  

• Wireless Auto Tachometer
  

• Alternator Signal Detector
  

• Automotive alarm system
  

• Road ice alarm
  

• Automotive Anti-Lock Brake Control Driver
  

• Headlight reminder
  

• Breath Alcohol Tester controlling a car ignition system
  

• Simple car battery charger
  

• Flashing / pulsing third brake like for cars
  

• Headlight flasher
  

• Speed alert - wireless portable unit
  

• Parking aid senses distance to rear of vehicle
  

• Automatic headlight brightness switch
  

• Car battery charger circuit
  

• Electronic car ignition circuit
  

• Car battery voltage tester using LM3914
  

• Synchronized multi-spark module (SMSM) for Electronic Ignition Devices (EID)
  

• Economy radar detector
  

• Headlight timer
  

• Parking sonar
  

• Fuel injector pulse width monitor
  

• BMW R Series Motorcycle Regulator Schematic
  

• 80188XL Engine Tachometer
  

• Integrate Fuel Pump Wire Security Cut Off with a Turbo Timer
  

• Simple Car Preamplifier and Artificial Earth
  

• FCD (Fuel Cut Defencer)
  

• Interface between GM's 5 Volt 8192 baud ALDL data stream and a PC serial port
  

• 5301 wideband fuel mixture display
  

• Wide Band Fuel Mixture Display
  

• 3rd brake light
  

• 12V to 9V car coverter
  

• Car Nicad charger
  

• Combination lock for car liftgate
  

• BMW motorcycle side stand protection mod
  

Data acquisition and data logging schematics

• Air flow detector
  

• Air flow detector
  

• Strain gauge sensor
  

• Digital Water Wave/Tide/Level Meter (PIC16F876)
  

• Self made data-logger V2.5 (second edition)
  

• Magnetometer
  

• Analog input section based on AD9220
  

• uModem 4+4/8 channel A/D board
  

• ADXL202 accelerometer to CV output
  

• Light direction sensor
  

• 12-Bit ADC interface
  

• Digital thermometer
  

• Universal flight controllers / datalogger
  

• Rain detector
  

• Home Brew Compass Sensor
  

• Using 555 Timer as an A/D converter
  

• ADC0804LCN 8-bit A/D converter
  

• Web-based thermometer project
  

• Low Flow-Rate Thermal Flowmeter
  

• Geiger counter
  

• Differential Capacitance Measurement for Tilt Meter
  

• Honey Bee counter (PDF)
  

• Capacitance type liquid level measurement (PDF)
  

• Thermostat node schematic
  

• Digital PC Oscilloscope
  

• Ultrasonic Range & Imager
  

• Precision Digital Altimeter
  

• Remote digital thermometer sends data over AC power line
  

• 4-channel data telemetry system
  

• Voltage follower with 1G ohm input resistance
  

• Digital compass schematic
  

• Temperature datalogger
  

• Serial Port A/D-converter
  

• Centronics port D/A converters and low-pass filter
  

• LCD Thermometer
  

• Wireless Liquid Level Sensing for Restaurant Applications
  

• Accelerometer Schematic
  

• Pressure Sensor-Based Altimeter Circuit
  

• Ultrasonic range finder circuit
  

• 1-wire barometer
  

• Water-level sensor
  

• Addressable ADC
  

• Electronic altimeter using PIC16F877
  

• Wireless weater station
  

Filter schematics

• Galaxy Noise Filter
  

• Low-pass active filter
  

• Filter Circuit for the Earthworm Seismic Data Acquisition System
  

• Active 2nd Order Filters
  

• RC Notch Filter (Twin T)
  

• Multiple Feedback Bandpass Filter
  

• CW filters
  

• Self-tune filter
  

• SSB AF filter
  

• Helical Resonator Notch Filter
  

• 3KHz low-pass filter plus audio amp (PDF)
  

• Active bandpass filters
  

• Bandpass filters
  

• Butterworth filters
  

• Narrow band audio bandpass filter
  

• Inversal notch and bandpass filter
  

• Chebyshev Bandpass Filter
  

• Bandpass filters
  

• Chebyshev / Butterworth filters
  

• Biquad Active Bandpass Filter Schematic
  

• "A" Weighting Filter For Audio Measurements
  

• Multiple Feedback Bandpass Filter
  

• Digital signal processor (DSP) for radio communications
  

• 29.85 MHZ bandpass filter schematic
  

• 29.85 MHZ notch filter schematic
  

• LC filter design
  

Games and fun stuff (schematics)

• Visor cradle serial interface
  

• Electronic coin tosser
  

• Electronic craps game
  

• First response monitor
  

• VCR ping pong game
  

• Video ping pong game
  

• MBC5/CPLD for the GameBoy
  

• GameBoy Camera Parallel Port Interface
  

• PSX controler to PC MIDI converter
  

• Dreamcast PC serial adapter
  

• GameBoy Cart Programmer
  

• Memory game
  

• 32 Kb x 8 emulator for the GameBoy
  

• Project: NES to Atari 2600 controller interface
  

• Battery Meter for Pinball Machines
  

• SRX1 (Stephane's Robotic eXperiment 1)
  

• Pine Racecar Victory Judge
  

• Interfacing Sony control stick to Empeg
  

• Electronic Nicad glow plug driver
  

• April Fools LEDs
  

• Pinewood Derby logic
  

• Quiz Master
  

• GameBoy Schematic
  

• GameBoy LCD schematic
  

• GameBoy Power & Cartridge schematic
  

• GameBoy ROM+RAM+MBC1 Cart Schematic
  

• GameBoy MBC1 circuit equivalent
  

• Super GameBoy schematic
  

• Quiz show indicator
  

• Dreamcast interface
  

• Flashing heart
  

• Phoenix programmer
  

• Funcard programmer
  

• Bingo!!! (on your tv)
  

• Slot car TV cronograph
  

• Furby reverse-engineered circuit
  

• Sanyo 20EZ monitor Arcade Game (300k ZIP)
  

• Burger Time Arcade Game (500k ZIP)
  

• Dig Dug Arcade Game (800k ZIP)
  

• Frogger Arcade Game (500k ZIP)
  

• Galaga Arcade Game (542k ZIP)
  

• Gyrus Arcade Game (800k ZIP)
  

• Junior Pacman Arcade Game (400k)
  

• Ladybug Arcade Game (335k ZIP)
  

• Mappy Arcade Game (470k ZIP)
  

• Moon Cresta Arcade Game (300k ZIP)
  

• Mr.Do Arcade Game (554k ZIP)
  

• PacLand Arcade Game (316k ZIP)
  

• Pengo Arcade Game (313k ZIP)
  

• Q*Bert Arcade Game (600k ZIP)
  

• Qix Arcade Game (476k ZIP)
  

• Scramble Arcade Game (600k ZIP)
  

• Time Pilot'84 Arcade Game (870k ZIP)
  

• Xevious Arcade Game (450k ZIP)
  

• Magic Wand Conjuring Trick
  

• Quiz game circuit
  

• E.S.P. Conjuring Trick
  

• DIT shutterglasses controller
  

• Tic-tac-toe game using PIC16F628
  

• Archery timer
  

• PIC micro Tetris game
  

• Magic lamp, IR remote control jammer and other fun circuits (PDF)
  

• Lego Mindstorms Double Rotation Sensor
  

Infrared based schematics

• IR detector
  

• Infrared body heat detector
  

• Stereo IR audio receiver
  

• General purpose IR receiver
  

• Wireless IR headphone transmitter
  

• Wireless IR headphone receiver
  

• Infrared remote control shutter release system
  

• Infrared transmitter for locomotives
  

• Infrared gate for door
  

• Infrared circuits for remote control
  

• Serial port controller infrared transmitter (PIC16F628)
  

• IR Receiver (Amplitude Modulated IR)
  

• IR Transmitter for Audio (Amplitude Modulated IR)
  

• Digibox interface
  

• IR remote control
  

• iRDA to TTL interface
  

• 40KHz light receiver (PDF)
  

• 40KHz TV-VCR repeater (PDF)
  

• Micro based PIR to IR remote converter
  

• IR-related ASCII Schematics V1.00
  

• Infrared remote transponder
  

• Build an Infrared night scope
  

• Decoding IR Remote Controls
  

• IR detector
  

• PC IR Remote Control Hardware
  

• PC IR Remote Control
  

• An Ambient-Light-Ignoring Infrared Active Motion Detector
  

• Simple on-off IR photoswitch without use of comparators
  

• Infrared gate (door entry alarm)
  

• Infrared switch using any infrared remote control
  

• Improved infrared receiver for PC with status LED
  

• Infrared link for 10-BASE-T / 100-BASE-T PC network card
  

• iRDA transceiver to extend IR port range up to 15 meters
  

• Infrared level detector for liquid level detection and proximity detection
  

• IR remote control tester
  

• Infrared Transmitter and Receiver schematic diagrams
  

• Pyroelectric Infrared Sensor
  

• Minimal Infrared transmitter for PC
  

• Simple IR transmitter circuit
  

• Simple infra-red detector
  

• Infra Red Switch
  

• IR remote control extender
  

• IR Remote Control Extender Circuit (Mark 2)
  

• IR Remote Control Extender Circuit (Mark 3)
  

• IR Link
  

• IR remote control tester
  

• 40khz IR Tester
  

• 555 timer 40khz IR Oscillator
  

• IR detector / emitter
  

• Fire-Stick infrared remote control
  

• Simple infrared remote control
  

• Infrared / Ultrasonic beacon
  

• Implementing Infrared Object Detection
  

• Computerized Infrared Remote
  

Laser related power supplies and data transmission

• Light beam receiver for laser pistols
  

• 12V supply for He-Ne laser
  

• Laser diode transmitter
  

• Laser power supply
  

• Laser transmitter/receiver
  

• Laser harp
  

• Laser Telephone Receiver Circuit
  

• Fiber Optic Voice Communications
  

• Efficient Laser Supply
  

• 20MHz VCSEL 3mW laser test circuit (PDF)
  

• 10MHz to 20MHz laser light detector (PDF)
  

• Micro-power 40KHz burst laser diode driver (PDF)
  

• 40KHz laser burst detector (PDF)
  

• Modulated laser diode tester (PDF)
  

• Ar/Kr Ion Laser Power Supply
  

• Laser diode power supply circuits
  

• RS-232 Laser Transceiver
  

• RS-232 laser transceiver
  

• Digital radar speedometer - laser reflexion using discrete logic
  

• HeNe laser power supply
  

• OPT201 Laser receiver
  

• OPT301 Laser receiver
  

• Laser transmitter schematics
  

• Diode Laser Power Supplies
  

• RS-232 Laser Transceiver
  

• Experimental laser data link
  

• Ar/Kr Ion Laser Power Supply Design
  

• Simple laser communicator
  

LED related schematics

• Big 7-segment LED display board with SPI interface
  

• LED Flasher
  

• LED pulser with audible output
  

• IR Illuminator
  

• Flashing Christmas LED display
  

• ICL7660 LED flasher
  

• LM3909 replacement using discrete components
  

• Color fade
  

• 1.5 Volt LED Flashers
  

• AC Line Powered LEDs
  

• Astable Multivibrator
  

• 9 Second Digital Readout Timer
  

• 9 Second LED Relay Timer
  

• 16 Stage Bi-Directional LED Sequencer, other sequencer and flaser circuits
  

• 10 Stage LED Sequencer
  

• 28 LED Clock Timer
  

• Fading Red Eyes
  

• Two Transistor LED Flasher
  

• 16 Stage Bi-Directional LED Sequencer
  

• Expandable 16 Stage LED Sequencer
  

• LED Photo Sensor Circuit
  

• LED chaser
  

• 7 Segment LED Counter
  

• 7 by 10 LED Moving Sign ( 27C512 EPROM)
  

• Sequencial LED Flasher with Reversable Direction
  

• Tri Color LED Controller with Serial Interface
  

• 1.5V LED flasher B (PDF)
  

• Low current LED flasher (PDF)
  

• 1.5V LED flasher A (PDF)
  

• Flashing LED advertising badge (PDF)
  

• Flashing LED advertising badge (PDF)
  

• Pulsed LED test circuit (PDF)
  

• Low battery voltage flasher (PDF)
  

• Adjustable flashing LED
  

• Knight rider scanning LED lights
  

• 3V LED chaser using 4017
  

• 6V ultra-bright LED chaser using 74HC4017
  

• Led display digital Voltmeter
  

• PWM white LED drivers
  

• Heart of LEDs
  

• Christmas Star
  

• Christmas tree
  

• LED Counter
  

• PIC16F84 LED chaser
  

• PIC16F84 LED signboard
  

• PIC16F84 LED signboard 2
  

• White LED circuits
  

• Assorted LED circuits
  

• LED Mood Light
  

• LED Audio VU Meter
  

• Robot Beacon rotating light using PIC12C508
  

• LM3909 LED flasher
  

• Animated LED signboard (PIC16C84)
  

• Picxie 2 - 8x8 Animated LED Signboard
  

Lighting schematics

• Garden light switch
  

• DMX lighting and special effects
  

• Microcontroller Multichannel Light Dimmer
  

• Disco style Strobe Light
  

• Varying Brightness AC Lamp
  

• 12 Volt Lamp Dimmer
  

• 120VAC Lamp Chaser Using Solid State Relays
  

• Flashing Neons (NE-51 / NE-2)
  

• Sequencing Neons (NE-51 / NE-2)
  

• Touch Activated Lamp
  

• 220V Flashing lights
  

• Coutesy lamp
  

• Bedside lamp timer
  

• TRIAC light dimmer
  

• 12VDC Fluorescent Lamp Driver
  

• Strobe light
  

• Adjustable Strobe Light
  

• RHINO8 EL Sequencer
  

• Light Sequenced Candelabra
  

• Light timer
  

• 5W Fluorescent light intensity modulator (PDF)
  

• 1W Fluorescent lamp night light (PDF)
  

• 6 Channel Auto Reverse Sequential Disco Running Lights
  

• Low-voltage light dimmer
  

• Light chaser
  

• Digi Pack DMX 512 lighting controller
  

• DMX PC keyboard interface
  

• 4-channel dimmer rack
  

• PIC16F873 light controller
  

• Digitally Addressable DALI Dimming Ballast (PDF)
  

• Disco light controller
  

• Neon desklamp
  

• Electronic night light
  

• Neon lamp dimmer
  

• LED Mood Light
  

• LX-800 Lighting system
  

• Xenon Strobe Light
  

• Lamp flasher/dimmer
  

Medical and health related schematics

• Snore alarm electronic device
  

• Heartbeat transducer
  

• ECG Amplifier
  

• EKG/EEG circuit
  

• Radiation Dosage-Rate Meter
  

• Heartbeat monitor
  

• Cranial Electrotherapy Stimulator
  

• Automated crib lights
  

• Jogging timer
  

• Tan timer
  

• Muscular Bio-stimulator
  

• Pedometer
  

• Simple lie detector
  

• Cardiac monitor
  

• Digital pedometer circuit
  

• Muscular Bio-Stimulator
  

• Sleeping aid based on electromagnetic-field radiation
  

• Salt taster - detects the amount of salt contained in liquid foods
  

• Electronic Stethoscope
  

• Galvanic Skin Response (GSR) Schematic
  

• Brain-Wave Machine
  

• Lie detector
  

• Simple lie detector
  

• The ESP SIM (Sound Impairment Monitor)
  

• Respiration system
  

Microcontroller based schematics

• PIC based packet radio encoder (PDF)
  

• RS485-Version of the SAB80C535-Microcontrollerboard
  

• PC IR receiver based on PIC16F84
  

• Record and play fast 1-bit sound on a PIC micro
  

• AT89C2051/4051scanning 7-segment display and keypad
  

• AT89C2051/4051 Driving dot LED
  

• AT89C2051/4051stepper motor interface
  

• AT89C2051/4051connecting dumb terminal
  

• Motorola 68K SBC (single board computer)
  

• 8051 SBC (single board computer)
  

• Simple RS232C Level Converter using Transistors
  

• Motorola 68HC11 evaluation board
  

• C-52 EVB Robot Controller
  

• Mains clock controller using AT89C2051
  

• AT89C2051/4051 Easy-Downloader
  

• AT89C51/52/55 Easy-Downloader
  

• PIC16F84 programmer
  

• PIC16F84 miniature real-time controller
  

• Isolated RS232 for PIC16F84
  

• PIC16F84 debugging terminal
  

• MiniLOGGER V1.0
  

• Analog datalogger based on T89C51RD2
  

• Atmel 89C Series Flash Microcontroller Programmer
  

• Atmel 89C2051 prototype board
  

• AT89C2051 real-time controller
  

• PIC12C508 Night-light saver
  

• AT89C2051 Night light saver
  

• Atmel 8051 Flash Based-Microcontroller Programmer
  

• AT89C2051 Digital thermometer and clock
  

• 4-Channel Timer using Atmel 89C4051 and MAX7219 display driver
  

• PIC16F84 CW decoder (PDF)
  

• 12C508 Smart Lock
  

• Basic Stamp based altimeter
  

• Interfacing EEPROM to a Basic Stamp
  

• Homebrew Basic Stamp project
  

• Interfacing the MAX186 8 Channel ADC to the BSII
  

• Interfacing the MAX187 ADC to the BSII to measure voltages
  

• RF remote control based on Basic Stamp
  

• 80C31 stepper motor controller
  

• Build a PIC controlled DDS VFO, 0 to 6 MHz
  

• PIC controlled DDS VFO, 0 to 6 MHz
  

• Basic Stamp Lightning Activity Monitor
  

• Parallel AVR programmer
  

• PIC16F84 line following robot
  

• PIC16C505 IR / wireless remote control
  

• Automatic door opener with PIC12C508
  

• RS485-like multi-drop bus with half duplex serial protocol
  

• 50 MHz frequency counter, voltage meter & SWR/PWR indicator
  

• Microcontroller board using the Atmel AVR AT90S8535
  

• Programmer PIC16F84,12C50x and EEPROM 24Cxx
  

• RDS Encoder - digital part
  

• PIC programmer for serial port
  

• Fully functional PS/2 mouse based on the PIC16F84
  

• PIC 18 programmer (PIC18F458, PIC18F452, PIC18C252, PIC16C745, PIC18F6620, PIC18F6720)
  

• Freign vocabulary recollector
  

• Illuminate holiday destinations on a world map
  

• Embedded system to send e-mails (small TCP/IP stack)
  

• Speaking clock using PIC & ISD device
  

• Speaking doorbell using PIC & ISD device
  

• Whistle detector using 8-pin PIC
  

• PIXpand
  

• PIC16F877 to IDE interface
  

• 68HC11 stepper motor control
  

• 90S2313 AVR Robot Board
  

• POCSAG encoder/decoder
  

• Network Time Protocol AVR Clock
  

• DS1820 Temperature Sensor Readout Unit
  

• Rotating Sprocket Wheel Generator (PIC16F84)
  

• Talking PIC - based on SP0256
  

• Serial to parallel converter using the AT89C2051
  

• AT89C2051 serial COMs to LED driver
  

• PIC16F877 Programmer And Development System
  

• DS1820 Arbiter V2.00 Schematic
  

• Microchip PIC ICSP implementation
  

• 101 AT Keyboard to ASCII Decoder using 68HC705J1A MCU
  

• LCD Serial Terminal
  

• Propellor clock (PIC16F84)
  

• Optical sensor using PIC12C508
  

• Interfacing S-7800A to PIC16F877
  

• A Scenix (and PIC) Programmer
  

• MMC to PIC16F876 circuit diagram
  

• 8088 maximum mode SBC
  

• EZ80 single board computer schematic (Z80)
  

• 8051 Development System Circuit Board
  

• Voice recording and message retrieval system
  

• Long-period watchdog timer
  

• Generate video signals in real-time using a PIC16F84
  

• PIC ICD
  

• Smart card programmer
  

• Jupiter card programemr
  

• Tutorial board for PIC16F84A microcontroller
  

• PIC Project #1 - RS232 to I2C Interface
  

• Galvanic decoupling of I2C bus
  

• Programmer PIC16F84,12C50x and EEPROM 24Cxx
  

• Dual PIC16C84 prototype board
  

• Graphic LCD interface
  

• Interfacing a 4X4 keypad to a BS2 using a 74922 encoder chip
  

• FSK modem with PIC16C84
  

• Talking YODA project (PIC16C84)
  

• PIC16F84/PIC16F87x-In-System-Programmer
  

• Microcontroller interface for 5KW microwave oven
  

• Using an I2C Serial EEPROM with a Basic Stamp 2
  

• PIC16F84 Based Morse Code Reader
  

• AVR-Based Serial Port IR Receiver
  

• Interfacing piezo elements to a microcontroller
  

• Victoria TAFE programmer (based on AT89C2051)
  

• JDM programmer
  

• PIC micro programmer
  

• Speech recognition using HM2007
  

• PIC microcontroller servo motor interface
  

• PIC micro multiple servo motor interface
  

• PIC16F84 countdown timer
  

• PIC16F873 ultrasonic range meter
  

• PIC16F873 Digital clock
  

• PIC16F873 remote display
  

• PIC16F84 stepper motor controller
  

• Way small web server
  

• PICADC - a free, PIC based "intelligent" A/D converter
  

• PIC-Programmer 2
  

• Connecting PIC12C508 8 to 93AA46 serial eprom
  

• KD7LMO Micro Beacon (PIC18F252)
  

• GPS LCD Display Project
  

• PIC16F84 LED chaser
  

• PIC micro LED projects
  

• PS/2 keyboard keystroke logger based on Atmel 89C2051
  

• Electronic distance meter based on Motorola 68HC908QY4
  

• Fan timer based on Motorola 68HC908QT2
  

• Atmel AVR and 8051 series ISP programmer
  

• AT89C2051 line-follower robot
  

• Night light saver (PIC12C508)
  

• USB and GLCD expansion board for 8051 SBC
  

• Microcontroller sensor and actuator interfaces
  

• Giant money counter (PIC16F876)
  

• PIC12C509 logic gate replacement for nitrogen filler
  

• PIC demo board
  

• PIC12C509 Gym Timer
  

• PIC LCD and Keypad driver
  

• PIC12C508 Phase Controller for 2kW heater
  

• PIC16F84 TRIAC / IGBT brightness phase controller
  

• PIC16F84 pulse monitor with date/time output (ZIP)
  

• Programmer for the 68HC705C8 MicroController
  

• 27c801 EPROM Programmer Project
  

• LCD to PIC16C54 schematic
  

• 68HC11 based RDS decoder
  

• Acceleration monitor using ADXL202 and AVR
  

• 40+ MHz 5-digit frequency counter with an AVR 2313
  

• Interfacing DRAM to AT90S8515
  

• Temperature monitor/controller: AVR 2313 / DS1621
  

• PIC micro to ISA bus interface
  

• Microchip PIC ICD (in-circuit debugger)
  

• Tony Nixons Pocket Programmer (PIC)
  

• PicoWeb V5.1 (AT90S8515) tiny web server
  

• Atmel 89C2051 In-Circuit Programmer Schematic
  

• 8051 Development System Circuit Board
  

• 8051 Development System Circuit Board
  

• Microprocessor using Xilinx FPGA
  

• Temperature controlled based on AT89CX051
  

• I2C LCD interface
  

• AFSK 1200 Modem based on PIC16C620
  

• PicCon - Hidden Radio Transmitter Controller
  

• PIC16F84 tone generator with source code
  

• PIC16F84 tone generator
  

• PIC16F84 tone generator (6-Bit)
  

• AVR Beacon Super Keyer
  

• AVR Frequency Counter
  

• AVR Digital Voltmeter
  

• AVR Signal Generator
  

• Ser-Key 10-Key Serial Keypad Encoder
  

• 2-wire LCD interface using PIC16CF84
  

• PIC16F84 Serial I/O-expander with PicBasic
  

• RS 485-RPT Schematic
  

• Camera remote control system using Basic Stamp
  

• Low cost Atmel in-system programmer
  

• Ultra low-cost programmer for AT90S family
  

• Connecting AT90S2313 with LCD display 2x16 char and 4x4 keypad
  

• Electronic safety lock based on ATtiny26
  

• GSM SMS remote control using AVR microcontroller
  

• 128x64 LCD Driver for AT90S2313 (ZIP file)
  

• Connecting LED to PIC Micro I/O pins (PDF)
  

• Microprocessor RS-232 Reset
  

• AT90S8515 experimenter board
  

• Multi-chip programmer for PIC microcontrollers
  

• Buffered PIC chip interface
  

• ScanMate audio activated recorded
  

• PIC vacuum fluorescent display interface
  

• PIC18F252 bootloader schematics
  

• PIC16F876 Datalogger
  

• Kodak DC-20 camera interface (PIC12C509)
  

• Kodak DC-20 camera interface (PIC16F84)
  

• PIC ICD in-circuit debugger circuit diagram
  

• Wisp628 ISP Microchip PIC Programmer
  

• WLoader - PIC16F877 application loader / bootloader
  

• Nixie clock (PIC16F876)
  

• Zilog Z80 thermostat embedded web server
  

• Picxie 2 - 8x8 Animated LED Signboard (PIC16F84) Picxie 2 - 8x8 Animated LED Signboard
  

• 10 tricks for interfacing to the PIC16C508
  

• Interfacing the PIC16C508
  

• PIC 5x7 display
  

• Analog to digital conversion notes
  

• Multi-chip programmer
  

Misc audio (also see Music, Amplifiers, Preamp)

• Electronic siren
  

• Two-tone siren
  

• Underwater microphone
  

• Code practice oscillator
  

• Noise generator
  

• Electronic whistle
  

• Twin-T Audio Sine Wave Oscillator
  

• 1.5V Audio Amplifier
  

• Low Power Op-Amp - Audio Amp (Intercom)
  

• 555 Tone Generator (8 Ohm Speaker)
  

• 3 Transistor Audio Amp (50 milliwatt)
  

• Low Frequency Sinewave Generator
  

• Automatic Charger for Battery Operated Hi-Fi Preamps
  

• Audio level indicator
  

• Room noise detector
  

• Amplifier timer
  

• Bell ring generator
  

• Amplified ear
  

• Precision audio millivoltmeter
  

• Six-channel Mixer and Amplifier
  

• Audio Signal Source
  

• Analog VU meter
  

• Voltage controlled amplifier
  

• Audio graphic equaliser
  

• Intercom preamp
  

• FET audio mixer
  

• Microphone mixer
  

• Tone control
  

• Digital volume control