Vacuum Tubes Valves
Musical & effects
Yagi Uda Antennas
Metal Detector Circuits
Liquid Sensing Circuits
Light Sensing Circuits
Voltage Detector Circuits
Air-Gas Detection Circuits
Human Sensing Circuits
RF & Radiation
Optical Sensing Circuits
Free Energy Circuits
AC to DC & DC to DC
Solar Cell Circuits
Micro Power Circuits
Switching Power Supplies
Light Laser LED
Digital to Analog
Analog to Digital
Data Bus Circuits
Voltage to Pulse
Current to Voltage
Frequency to Voltage
RF Converter Circuits
Sine to Square Wave
Voltage to Current
voltage to frequency
Period to Voltage
Video Wall circuits
TV Video Circuits
Motor Control Circuits
8051 / 8052
PCB CAD Software
Car bike Circuits
555 Timer Circuits
Remote Control Toy
H Bridge Circuit
DIY HV Variable Cap
DIY PMA alternator
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
AVR Microcontroller Circuits
AVR Microcontroller Circuits
Very Low Noise Pick-up Preamplifier
The preamplifier was designed to signal sources such as low-impedance moving coil cartridges (MC) on turntables high fidelity (and yet still there). The impedance of the amplifier is 100 W. To keep the noise levels low, three double-type transistors MAT03 SSM2220 or linked together to form a differential amplifier. Connecting this amp in front...
AVR Programmer (AT90S2313)
The ATMEL, with family AVR, was consolidated in the field of microcontrollers. The microcontrollers are, providing fast core and a variety of peripherals. These features continue to occupy the attention of engineers and earn their preference. The developer will see, it accepts all models of the family of AVR. It is an excellent tool that stands...
Simple AVR Programmers
These are simple AVR programmers. I designed and built four different programmers for various envilonments: LPT controlled parallel programmer, LPT controlled ISP adapter, COM controlled ISP adapter and COM controlled generic SPI bridge. Additionaly, COM controlled adapters can be used as a communication cable between host PC and target board,...
Clock/Calendar/Alarm with ATtiny12
This is the timekeeping test circuit. It includes a one-transistor circuit to switch in the 5V power supply when present and drop back to the 3v battery the rest of the time. That loop of blue wire-wrapping wire is a lariat used to quickly and easily pull the chip out of the socket during development without damage and without having to reach...
AVR FM Stereo Transmitter
A composite stereo signal, as transmitted by FM radio stations, is composed of at least three parts: A base band mono signal, a double sideband channel difference signal, and a pilot carrier. The signal composition is somewhat analogous to an NTSC composite color television signal. I said "at least three parts" because some stations transmit...
100 MHz RF oscillator with ATtiny12
A frequency reference for tuning up the RS-232 to 100 MHz RF desktop channel adapter elsewhere on this site, when I found this Saronix crystal oscillator in my junk box. A few minutes with AVRStudio produced an ATtiny12 to make a tone - even fewer parts than using an NE-555. With the addition of a transistor to gate the output, I was set to go....
Simplest and low cost USB AVR
This is the low cost AVR programmer using attiny2313. The schematic diagram is given below. First setup the circuit as shown. One important care taken to make fuse bit avrdude -c usbasp -p t2313 -U hfuse:w:0xdf:m -U lfuse:w:0xef:m If you use serial port to write the program , use stk200 command instead of usbasp.
Interfacing DRAM M5M44800 Memory with AVR AT90S8515
Is it possible to use DRAM with microcontroller AVR? Yes, it is possible. Jesperh has proved it. He hooked up a DRAM to a small processor (in this case an Microcontroller Atmel 8515), and handle the RAS/CAS sequencing and refresh in software. The type of DRAM is Hitatchi M5M44800, a 512k*8 DRAM!. Bigger than the original memory of...
LC Resonant Frequency Meter
Recently, I have needed to measure inductances in the hundreds of microhenries to several millihenry range. Though I have a pretty good LRC meter and an excellent bridge on my workbench in Mesa, Arizona, I wanted to make these measurements in my home in Thailand, thus I decided to put something together. The RF Inductance meter on this website...
AVR LED RF Field Strength
Useful as a transmitter tune-up meter or an RF sniffer, this is an RF field strength indicator that is loosely based on the Broad Band RF Field Strength Probe, described elsewhere. It detects RF via a square law detector, basically its a crystal set with gain. The bias circuit for the detector is significantly modified from the probe to reduce...
AVR Robot Board
The Atmel AVR series are very good microcontrollers with quite a rich instruction set, rich enough that lots of folks have good compilers for them so we don`t have to learn their assembler. A very rich compiler available is the BASCOM/AVR compiler from MCS Electronics. I`ve used this compiler for prototyping the software on my 90S2313 robot...
Versatile digital speedometer uses few components
A speedometer measures a wheel`s rotational speed. Unlike conventional mechanical and moving-magnet designs that use analog moving-pointer displays, the electronic speedometer in this Design Idea features a digital readout and a power-saving device that uses few components. Figure 1 shows the digital speedometer`s circuit design. An Atmel AVR...
Radio Spectrum Monitor
This is an experimental work to monitor a spectrum pattern of radio band, and is a continuous project from Audio Spectrum Monitor. To analyze the spectrum of an input signal, I chose an Atmel`s AVR microcontroller used in Audio Spectrum Monitor to process FFT. When think it easy, it can be thought that sample an input RF signal directly and...
Ponyprog for AVR & PIC16F84
All resistors are 1/4W.The circuit is powered by 9...15V DC or AC. When In Circuit Programming (ISP) connectors are used, is possible the programmer to be powered from target?s power source. Diodes D2 and D6 protect the regulator LM7805, when target?s power is used. ?PIC JUMP? is used to switch between Microchip?s PIC and ATMEL?s...
To program some AVR microcontroller unit (MCU) you will need an AVR programmer. The better way to do that, is to buy some development kit like STK-500. This kit have the advandage to give you serial port, LCD connector, SRAM socket, 8 switches, 8 LEDs, connectrors for all of the ports of MCU and more, to one board. I sugest to beginers, to...
GP display controller
This is a simple display controller. It can be controlled with a small microcontroller, such as MCS51, 68HC11, Z80, AVR and others. Several years ago, I found an article that controlling a TV with only a PIC micorcontroller, and I surprised to it. It is very interesting to attempt to synthesize video signal with a micorcontroller. However,...
10Hz - 100KHz Function Generator with AT90S1200
The presented project is a function generator for sinusoidal and square signals production. The output frequency covers the range from 10 Hz to 100 KHz with a step of 2 Hz. The waveform synthesis is based on the D.D.S. technique (Direct Digital Synthesis) and the output frequency is selected through a microcomputer with an embedded thumb...
Step Motor Controller
This application note describes how to implement a compact size and high-speed interrupt driven step motor controller. Step motors are typically used in applications like camera zoom/film feeder, fax machines, printers, copying machines, paper feeders/ sorters and disk drives. The high performance of the AVR controller enables the designer...
CodeLock AVR electronic combination lock is realised with Atmel AVR microcontroller AT90S2313 or ATtiny2313. Program in hex code is 2 kB long. User code is consisted of 1 to 4 digits. If you buy the chip than user code is consisted of 1 to 8 digits. If the code is entered in the correct sequence, then after 1 second the relay and the electric...
Simplest AVR programmer
An In Circuit Programmer is a very valuable tool. Not only does it allow you to program you AVR's with ease, you can update your program without having to remove the AVR (very use full when working with surface mount devices). Also, an ICP allows you to use one tool to program possibly every AVR available today.
Control of three phase Induction motor AT89S52
This Project can be used with the three phase Induction motors. The circuit will take the full control of the motor and it will protect the motor from several faults such us over voltage and under voltage and the circuit will switch on the motor under safety conditions.
Automatic Bell AT89S8252
This Project takes over the task of Ringing of the Bell in Colleges. It replaces the Manual Switching of the Bell in the College. It has an Inbuilt Real Time Clock (DS1307) which track over the Real Time. When this time Equals to the Bell Ringing time, then the Relay for the Bell is switched On.
Auto plant Irrigation AT89C2051
The Project presented here waters your plants regularly when you are out for vocation. The circuit comprises sensor parts built using op-amp IC LM324. Op-amps are configured here as a comparator. Two stiff copper wires are inserted in the soil to sense the whether the Soil is wet or dry.
Biomedical Monitoring circuit AT89C2051
In spite of the improvement of communication link and despite all progress in advanced communication technologies, there are still very few functioning commercial wireless monitoring systems, which are most off-line, and there are still a number of issues to deal with.
LED display Digital Calendar AT89C2051
This Project Digital Calendar using Microcontroller is an advanced digital calendar, which displays the Date, Day, Month over the LED display. It has an 8 bit Microcontroller which runs on the Program embedded on its ROM. Separate LEDs are provided for the date, day, and month. The system has an battery backup so that it can run over all the...
LED Countdown Timer with AT89C2051
A simple count-down LED timer that counts in minutes and seconds. Three buttons below the LED provide control of the unit, allowing you set the desired countdown time in minutes and seconds and a start/stop button. Completion of the countdown is indicated by an alarm that starts when the countdown has finished and the display reads zero.
Digital event Counter AT89C2051
Digital visitor counter is a reliable circuit that takes over the task of counting Number of Persons/ Visitors in the Room very Accurately. When somebody enters into the Room then the Counter is Incremented by one and when any one leaves the room then the Counter is Decremented by One. The total number of Persons inside the Room is displayed on...
Components Tester with AT89C52
This Project Components tester can be used to check the electronic components such us Diode, Transistor, Capacitor, IC555, IC741 and Continuity. The whole circuit was controlled by the Microcontroller AT89C52. The circuit has an LCD display it was used to display the Text messages over it. The system will display the conditions of the device on...
LED Digital gated Emulator using AT89C2051
This project Digital gated Emulator using Microcontroller is used to emulate the basic gates such us NOT, OR, AND. The system has the selector switch by which we can select any gate. The system has two inputs and one output. We use two SPDT switches for the inputs and for the output we use an LED.
LCD Caller ID with AT89C2051
This Project can be used in home, shops, offices etc. It keeps tracking of both Incoming and Outgoing Calls. It has a built in Caller ID. The incoming and the dialed numbers are displayed on the LCD display. The system will display the numbers over the LCD display.
Solar tracking System with AT89C2051
This is a power generating method from sunlight.This method of power generation is simple and is taken from natural resource. This need only maximum sunlight to generate power. This project helps for power generation by setting the equipment to get maximum sunlight automatically. This system is tracking for maximum intensity of light. When there...
SMS through Telephone with AT89S8252
The main objective of this system is to transmit message or text through ordinary Land Line Telephone from one end (source) to another end (designation). This is get achieved by the DTMF technology. It has two sections one for editing the text and to transmit the edited text and the other section consist for receiving the text message. The...
Arduino Projects and Circuits
PIC Microcontroller Circuits
Microcontroller Programmer Circuits
68HC11 Microcontroller Circuits
8051 / 8052 Microcontroller Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
DIY HV Variable Capacitor
DIY PMA Alternator Plans
Digital Signal Integrity