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
8051 / 8052 Microcontroller Circuits
8051 / 8052 Microcontroller Circuits
MIDI Drum Machine Project
The MIDI Drum Machine began in the Fall of 1991 as a project for a microprocessor system design course, shortly after I wrote PAULMON1, the 8051 monitor/debugger. A friend, Rod Seely, both a musician and electronics hobbiest suggested I design something using the Musical Instrument Device Interface, MIDI, that would be COOL and would work...
A serial to parallel converter using the AT89C2051
The example program included with the PG2051 evaluation kit is a basic serial to parallel converter written in 8051 assembler. This is probably a good example of the uses to which an AT89C2051 can be put - it would be hard to get a serial to parallel converter much simpler than the single 20 pin IC in this circuit. The program is meant to serve...
Use 8051`s power-down mode to the fullest
The 8051 series µCs offer idle and power-down modes, both of which you invoke by setting appropriate control bits from the code. For instance, a 5V, 12-MHz Atmel AT89C2051 consumes approximately 9 mA in active mode, 1.8 mA in idle mode, and only 12 µA in power-down mode. Although power-down savings outperform those of the idle mode by two orders...
An 89C2051 CPU 8 driver outputs
This document describes the HSETI PCB. This PCB is a small simple application for the Atmel AT89C2051 microprocessor - a 20 pin 8051 variant, with FLASH (reprogrammable) program memory. The board has just two chips on it, the CPU and a driver/buffer.
Microcontroller makes effective frequency counter
Figure 1 shows an efficient and cost-effective frequency counter using an Atmel 89C2051 µC (Reference 1). The design can use any µC of the 8051 family. The circuit counts frequency and sends the count to a PC via the serial port. The signal connects to pin 3.4 of the µC. The TTL-compatible output of the µC drives the 1488, which converts the...
8052.com Single Board Computer (SBC)
The 8052.com SBC is a single-board computer designed to be both useful and instructive in illustrating certain concepts commonly encountered in 8052-based development.
Below is a rough schematic of the layout of the accelerometer PC board looking from the component side. The microcontroller is an Atmel AT89S8252, an 8051 clone. This microcontroller is in-circuit programmable using an SPI interface. The SPI pins are also used to drive the MMC. To permit the dual use there is a jumper block (located below the...
Interface LCD with ease
The circuit in Figure 1 saves I/O pins. It uses an 8051 µC, and only four I/O pins (P1.0 to P1.3) drive the LCD, instead of the 11 pins other displays require. Data transfers in a serial mode through the P1.0 port of the µC. The µC interfaces to Pin 2 of IC1, a 74HCT4094 8-bit shift register. Serial data advances on every clock pulse and...
Serial MIDI Interface
This page describes how to build this full-bandwidth single-port (one input and one output) MIDI interface. The interface is buffered (that is, if the PC gets behind you won`t lose data) and it works in Windows 3.1 and Windows 95 using a special (and very well-behaved) device driver. A simpler version, using an Atmel AT89C2051 microprocessor, is...
Interfacing Alphanumeric LCD To Microcontroller
The link shows how to inteface Alphanumeric LCD to 8051 Microcontroller. Liquid Crystal Display also called as LCD is very helpful in providing user interface as well as for debugging purpose. The most common type of LCD controller is HITACHI 44780 which provides a simple interface between the controller & an LCD. These LCD's are very simple to...
Interfacing Relay To Microcontroller
Relays are devices which allow low power circuits to switch a relatively high Current/Voltage ON/OFF. For a relay to operate a suitable pull-in & holding current should be passed through its coil. Generally relay coils are designed to operate from a particular voltage often its 5V or 12V. The function of relay driver circuit is to provide the...
Interfacing seven segment to microcontroller
The Tutorial shows how to interface 7-segment display to a microcontroller. Also explains how do display more than one 7-segment on same data lines using scanning method. 7 Seg displays are are basically 7 LED's. It will be much easier to understand if you first read Interfacing LED's to Microcontroller.
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.
Auto light Controller and Visitor Counter
This Project Automatic Room Light Controller with Visitor Counter using Microcontroller is a reliable circuit that takes over the task of controlling the room lights as well us counting number of persons/ visitors in the room very accurately. When somebody enters into the room then the counter is incremented by one and the light in the room will...
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.
Bluetooth for Symbian OS Mobiles
Use your Symbian OS mobiles to control devices through Bluetooth. The serial to Bluetooth converter from sparkfun.com is used in this project. The Microcontroller At89C2051 is used to receive the data from the mobile through bluetooth. Most of the Nokia smartphones can be used in this project.
PC home light control system
This project describes a new economical solution of home light control systems. The presented home light control system can be used for different sophisticated home applications. The control system consists of a PC, and control circuitry and the electrical devices.
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 IC Tester for 74 series
The chip tester verifies the functionality and timing of a variety of 7400 series integrated circuits. Students taking Digital Logic Design Lab, Use these chips often in their laboratory. The IC to be tested should be placed on the ZIF socket and the Microcontroller prompts the user to enter the IC number of the chip to be tested. After...
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...
Digital Temperature Controller
This Project is used to indicate the temperature and it is also used as controller. The system will get the temperature from the IC and it will display the temperature over the seven segment display and this temperature was compared with the value stored by the user and if the Room temperature goes beyond the Preset temperature then an alarm is...
High Precision Temperature Indicator
This project is an High precision digital thermometer which indicates the temperature on the seven segment display. It has an resolution of 0.06deg. The 1 wire temperature sensor IC from Maxim semiconductors is used as the sensor. The DS18S20 Digital Thermometer provides 9bit centigrade temperature measurements and has an alarm function with...
Cash Register circuit
The Electronic Cash Register (ECR) keeps track of sales transactions quickly and effectively. An abundance of PLUs (Price Look Ups) and department keys accommodate a variety of merchandise items. This means a faster, more accurate check out process and the ability to manage a wider variety of goods and services more efficiently. And with...
Voting Machine circuit
Now-a-days Electronic voting machines are being used effectively. The confidence of the voter in its flawless working is gradually building up and these machines are thus becoming quite popular throughout the country. Features of the electronic voting machine include avoidance of invalid votes and reduction of counting time and the consequent...
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...
FingerPrint Security circuit
Personal Safes are revolutionary locking storage cases that open with just the touch of your finger. These products are designed as secure storage for medications, jewelry, weapons, documents, and other valuable or potentially harmful items.These utilize fingerprint recognition technology to allow access to only those whose fingerprints you...
Fighting Robot circuit
The need for a device that can detect and extinguish a fire on its own is long past due. Many house fires originate when someone is either sleeping or not home. With the invention of such a device, people and property can be saved at a much higher rate with relatively minimal damage caused by the fire. Our task as electrical engineers was to...
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.
Home Security System with microcontroller
Security is a prime concern in our day-today life. Everyone wants to be as much secure as possible. An access control for doors forms a vital link in a security chain. The Microcontroller based Home Security System can be adopted at Home it has various type of Sensors. In our Project we have magnetic sensors, Wire Loop sensors, Fire sensors. The...
Arduino Projects and Circuits
PIC Microcontroller Circuits
AVR Microcontroller Circuits
Microcontroller Programmer Circuits
68HC11 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