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Computer Interface Circuits

Computer Interface: 
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Last Updated: December 25, 2017 01:48 PM

Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

M Asim Khan's Programmer Ver 3.1 Latest M Asim Khan's Programmer featuring more chips, enhance programming speed, support Window2000/XP.  New target chips, 87C51 and 87C52.   __ Designed by Wichit Sirichote

Machine Independent Parallel Interface To the electronics hobbyist perhaps the most useful interface on an IBM PC or compatible is the parallel port.  All manner of hardware can be attached to this port and subsequently controlled with a few lines of C or BASIC.  Of course not all personal computers are IBM clones and some may not have a parallel port at all.  It can happen that the owners of these errant machines are also electronics hobbyists. __ Designed by David Tait

Macro that combines a complete USB transaction layer with an 8051 microcontroller core and a functional block that implements the application-specific functions.  This macro was developed and is supported by Trenz Electronics for use with an XSV Board

Mag Card Reader The unit provides the magnetic head on a spring mechanism along with low level head signal amplifiers and data slicers.  Three signal lines coming from the unit provide card presence, clock, and data.  When actively reading a card, it draws about 50ma of current at 5 volts.   __ Designed by Luhan MonatMesa Arizona

Mains Frequency Meter Mains frequency is pretty stable and it is unlikely that you have to measure it but if you have an emergency generator you might find this circuit useful as it will give an indication whether the generator is running too fast or too slow.  Actually you can use the mains frequency to calibrate

Mains Manager Very often we forget to switch off the peripherals like monitor, scanner, and printer while switching off our PC.  The problem is that there are separate power switches to turn the...__ Electronics Projects for You

Mains Operated Remote Control Tester This handy remote control tester responds to the signal received from any infrared hand-piece (IR remote control).  Circuit and working Fig.1 shows circuit diagram of the remote control tester.  It is built...__ Electronics Projects for You

Mains-operated Capacitive Sensor Easily adjustable, high sensitivity circuit; Minimum parts counting __ Contact: Flavio Dellepiane, fladello @ tin.it

Maintain precise timing with PC's speaker logic 07/11/02 EDN-Design Ideas Precise timing control is paramount in data acquisition and analysis and especially in digital-signal processing.  The easiest way of maintaining timing control in a PC is to use delay loops.  The disadvantage of this implementation is that the delay loop's elapsed time depends on the system's operating frequency __ Circuit Design by DS Oberoi, CEDTI, and Harinder Dhingra, GCET, Jammu, India

Make a printer port EEPROM programmer & dongle 05/13/04  EDN-Design Ideas You can easily use a PC's printer port for serial-EEPROM programming.  You can use a device-programmer circuit used to program the MicroWire serial EE-PROM 93CXX (Figure 1).  The circuit is so simple that any further simplification se __ Circuit Design by GY Xu, XuMicro, Houston, TX

Make eight-channel measurements through an LPT port 06/13/02 EDN-Design Ideas The circuit in Figure 1 represents a simple and cost-effective way to obtain eight-channel analog-signal acquisition through a PC's LPT port.  IC1, a 12-bit, serial-output MAX187 ADC, operates from a single 5V supply and accepts analog inputs of 0 to 5V.  IC2, an eight-channel MAX338 analog multiplexer, also operates from a single 5V supply __ Circuit Design by J Jayapandian, IGCAR, Tamil Nadu, India

Make Simple Circuit FSK Modulator 10/11/01 EDN-Design Ideas The need for a compact telemetry system poses a challenge for designing a small, light, low-component-count system.  Interfacing serial data from the microprocessor is also difficult because most low-cost RF transmitters do not accept dc levels at the input.  Commercial FSK(frequency-shift-keying] modulators are bulky and need many passive components __ Circuit Design by Shyam Tiwari, Sensors Technology Ltd, Gwalior, India

Make Your Own Single-Side PCB for Easy-Downloader V1.1 I am very happy with my student, Plermjai (his name means feel delighted too) Inchuay (his family name means angel helps him) , who provides me his page describing how-to-make a single side PCB for the Easy V.1.1.  So cool! his prototype was made by hand writing with a pen for making PCB! Available now single side with Protel format.   __ Designed by Wichit Sirichote

Make Your Own Single-Side PCB for Easy-Downloader V2.0 This work was contributed by Bruno Macio from Brazil, a single-side PCB for Easy II with MAX232C for RS232 level converter.  For those who use Portuguese may ask him directly __ Designed by Wichit Sirichote

Mass storage & printer interface for the FX-700P calculator This device attempts to emulate the original FA-3 cassette interface and the FP-12S thermal printer.  Files are stored in an onboard EEPROM or transferred through the serial port, depending on the software version.  Data directed to the printer are transmitted through the serial port or an optional parallel port, again depending on the software version. __ Designed by Piotr Piatek

Mathematical Manipulation Of Pure Sine Wave Inverter using ATMEL 89S2051 Didik Rostyono and Harsono Hadi explain how to produce the sinewave output inverter using the ATMEL microcontroller! (available only in pdf file (274kB) , click the link to download it) __ Designed by Wichit Sirichote

MAX555 PLCC to TQFP Printed Board PC B Layout Guidelines App Note/ 1120 / Mar-09__ Maxim Integrated

MCS-51 endows MicroLan-like protocol to UARTs 05/07/98 EDN-Design Ideas NOTE :  Page includes several designs, scroll to find this one.   Piezoelectric buzzers, such as the Murata(Smyrna, GA]PKB5-3A in Figure 1, make excellent alarms.  They're compact, lightweight, efficient, and reliable.  However, a piezo alarm is a dc device; it requires additional circuitry to operate from an ac source __ Circuit Design by SK Shenoy, NPOL, Kochi, India

MCU_PG.Zip New Program and firmware for SUNROM Programmer by Majid Mahmoud Pour Eftekhari Foumani from Iran.   __ Designed by Wichit Sirichote

Memory Card Reader SD memory cards, especially the ones under 1GB are cheap, relatively easy to interface and provide vast amounts of memory for imbedded control.   __ Designed by Luhan Monat-Mesa Arizona

Method provides automatic machine shutdown 27-May-04 EDN-Design Ideas Some machines need to run for long periods and therefore may finish their work in the middle of the night or during the weekend.  For the time remaining, until the operator returns, the machines stay idle, uselessly consuming power.  This design idea allows a machine to completely shut itself down after finishing its work __ Circuit Design by Jean-Bernard Guiot, Mulhouse, France

Method provides fast, glitch-free isolation of I2C & SMBus signals 24-Jun-04 EDN-Design Ideas I2C is a popular serial protocol for power controllers, ADCs and DACs, EEPROMs, and other devices.  In certain data-acquisition and power-control situations, you must isolate the I2C master from one orslave devices for noise, grounding, or safety issues.  Also, although 128 peripherals may connect to the bus, at some point, differences in ground potential and excessive bus capacitance __ Circuit Design by Mark Thoren, Linear Technology Corp, Milpitas, CA

MIC2527 Voltage Drop, Packaging & PCB Layout App Note 30 -- MIC2527 Voltage Drop, Packaging, and PCB Layout __ Designed by Micrel

Micro-C Library Extension for DS1202  Real-time Clock A Library extension and example circuit to interface DS1202 with 8051 chip.   __ Designed by Wichit Sirichote

Microcontroller drives logarithmic/linear dot/bar 20-LED display 01/18/07  EDN-Design Ideas Do-it-yourself analog-to-LM3914 display driver offers user programmability __ Circuit Design by Dhananjay V Gadre and Anurag Chugh, Netaji Subhas Institute of Technology, New Delhi, India

Microcontroller eliminates offboard EEPROM with "virtual-EEPROM" routines 05/10/01 EDN-Design Ideas COP8flash µCs let you allocate some of their internal flash memory as a nonvolatile storage space.  This line of flash µCs accomplishes this task by accessing some memory functions built into the boot ROM.  In addition to some of these memory functions, the COP8flash µC can initiate and control in-system programming under software.  You can use 'virtual EEPROM,' although __ Circuit Design by Wallace Ly, National Semiconductor Corp, Santa Clara, CA

Microcontroller programmer taps power from PC’s serial port 04/26/07  EDN-Design Ideas A PC's serial port can supply enough power to supply a microcontroller programmer __ Circuit Design by GY Xu, XuMicro, Houston, TX

Microcontroller sensor & actuator interfaces The high current driver circuit is used when you need to supply more than a few mA to a load such as an LED or a relay.  In this example the I/O pin of your microcontroller such as a BASIC Stamp is driving the base of the transistor Q1 through a 1K resistor and diode D1.  The diode is there because if Vcc on the transistor is higher than 5V you don't want that coming back into your microprocessor, the 1K resistor is there to limit the current into the base of the transistor __ Designed by Chuck McManis

Microcontroller Supervises 0- to 20-Ma Protection 08/26/10 EDN-Design Ideas A microcontroller replaces fuses and trip circuits.    __ Circuit Design by Anatoly Andrusevich, Maxim Integrated Products

Microprocessor RS-232 Reset This circuit allows a remote microprocessor to be reset by a controlling host over a remote RS-232 or similar protocol serial line.  With the use of a program loader on the remote host, a program may be downloaded and run.  This allows a target processor to run different code in RAM, thus getting rid of the need to burn multiple EPROMs.  The circuit is usually used for developing code on a target processor, but it can also be used for permanent applications where the target program lives on a host system's disk __ Designed by G. Forrest Cook

MIDI cable for Sound Blaster cards The cable that Creative Labs wants to charge you $50 for doesn't contain much in the way of parts.  If you have the pieces laying about and you've got to hook your Sound Blaster up to your synthesizer, you may just want to build your own.  I had to build my own and tell others how to do likewise because the very thought of giving Creative Labs another $50 after paying them $150 for an atrocious software developer's kit was more than I could stand. __ Designed by Frank Crivelli & Peter Crowcroft

MIDI Controlled Switches Drives up to128 individual relays, solenoids, motors, etc.  with a MIDI note-on and note-off messages  

MIDI Controller Foot Pedal Here's a simple project that sends continuous or switch controller MIDI messages that correspond to the position of a potentiometer.  Given a few parts and a cannibalized volume or wah-wah pedal, you can build this MIDI controller pedal and have the ultimate source of controller data in the Universe.  This pedal is especially useful in live performance, but it's also great to have around when sequencing.  An added bonus: the MIDI Footpedal sports a panic button that will silence any stuck notes that come your way.   __ Designed by Paul Messick

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.   __ Designed by Paul Stoffregen

MIDI Generator Control some MIDI device with ATtiny26.  The code can be convert it for any AVR family microcontroller __ Vassilis Stergiopoulos

MIDI Keyboard Build a PIC based DIY midi keyboard for under $30 and by using free VSTs   (virtual instruments) you get a powerful music creation system

MIDI to RS232 adapter The article contains two parts: a description of a circuit that translates the MIDI signal level to RS232 levels   (and vice versa) , and programming notes to send and receive MIDI packets.  The first part, the circuit, is general purpose --although using this converter to connect a MIDI keyboard to the serial port of your PC may require a special RS232 card.  The second part, though, is specific to the H0420 programmable MP3 player.  In fact, the article was written specifically to connect this MP3 player to a MIDI chain

MIDI-Mate: a MIDI Interface for PCs Easy-to-build project connects to your PC's sound card to provide full MIDI input and output ports.__ SiliconChip

Miniature Real-Time Controller My long history homeuse controller, a Miniature Real-time Controller controls night light, A/C, household appliances with programmable scheduler.  Modified source code and hex file for year 2002 readout.  New source code in c program.   __ Designed by Wichit Sirichote

Minilogger V1.0 Build your own a personal data logger for recording analog signal.  The MiniLOGGER provides 8-channel analog input (-99mV to +999mV) ,  __ Designed by Wichit Sirichote

Modem-access adapter reduces interference EDN-Design Ideas 07/22/1999   The modem-access adapter (MAA) in Figure 1 has features that reduce problems when modems and phones share the same line.  The design also overcomes the shortcomings of modem interference protectors.    __ Circuit Design by Thomas Schmidt

Modified DDS Functions as Baud-Rate Generator 07/15/10 EDN-Design Ideas Direct digital synthesys lets you generate a clock at frequencies needed for a standard serial port.   __ Circuit Design by Vardan Antonyan, Glendale, CA

Module Gives Voice to PC EDN-Design Ideas 05/26/94    The circuit in Fig 1 uses the ISD1020A voice-record/playback chip (Information Storage Devices, San Jose, CA, (800) 825-4473) to allow an IBM PC to speak and hear.  The analog part of the circuitry comes from the company's application notes.  The host PC controls address inputs (A0 through A7), Chip Enable (CE), Playback/Record (P/R), and Power Down (PD).  The host also—supposedly—monitors End Of Message flag (EOM).   __ Circuit Design by Jerzy R Chrzaszcz, Institute of Computer Science, Warsaw University of Technology, Warsaw, Poland

Monitor Network Compliant48V Power Supplies DN290 Design Notes __ Linear Technology/Analog Devices

Monovibrator Uses Three PLD Pin 09/28/95 EDN-Design Ideas If your design requires a precise monovibrator, you don't want to use the circuit in Fig 1.  However, if sharp timing isn't crucial and you can afford just three spare PLD pins, this circuit is an alternative to using yet another 555.  The circuit comprises asynchronous logic, an open-collector-like driver that controls the discharge of an external capacitor __ Circuit Design by Jerzy Chrzaszcz, Warsaw University of Technology, Warsaw, Poland

Morion MV89A Oscillator Repair While testing three Morion MV89A oscillators I got from eBay, I found that one of them had a weak output __ Designed by Roberto Barrios EB4EQA

Motorcycle Computer Board with Nokia 6610 LCD In this project you will see how to use Nokia 6610 Lcd, connected with microcontroller PIC18F4455. __ Designed by © Ivica Novakovic

MP-3 Stereo Transmitter with USB control from a PC This low cost MP-3 player was designed to be run from a PC via a USB interface.  The MP-3 audio from a PC sound card is transmitted to a home stereo via a synthesized FM Transmitter.  Also included is a 433 MHz wireless remote control to provide basic VCR type functionality to the whole design.   __ Designed by Steve Hageman

MS-DOS EEPROM Programmer Small serial EEPROMs are commonly used in modern electronic equipment for storing non-volatile data.  They are used in equipment like: TV sets, VCRs, Satellite receivers and even cell phones.  There they are mainly used for storing tuning and calibration data

MSP430's Port-Interrupt-Request Logic Helps Debounce Contacts 04/08/10 EDN-Design Ideas Use the MSP430’s port-interrupt-request flags to save switch input transitions for debouncing(EDN  Design Ideas] __ Circuit Design by Richard Neubert, Manchester, NH

Multichannel, 12-Bit Interface Connects to PC 04/25/96 EDN-Design Ideas The circuit in Figure 1a connects a multichannel, 12-bit precision ADC to an IBM PC or compatible.  The low-power consumption of the 12-bit serial ADC, IC1, makes it a suitable candidate for connection to the PC through the parallel printer port.  The circuit uses the PC's serial port (COM2) to supply the necessary 5V (Figure 1b).  In this application, you program the serial port to provide the ±VCC for other associated components.  An LM336 5V reference zener diode generates 5V for the ADC. __ Circuit Design by Dhananjay Gadre, IUCAA Instrumentation Lab, Pune, India

Multiple Output DC/DC Converter Runs Off 2-Cell AA Batteries USB or AC Wall Adapter DN1006 Design Notes__ Linear Technology/Analog Devices

Multiple PSUs share load 08/21/13  EDN-Design Ideas Combine two or more power supplies to share a heavy load __ Circuit Design by Vardan Antonyan

Multiply Your Sampling Rate with Time Interleaved Data Converters App Note/ 384 / Sep-07) __ Maxim Integrated


Computer Interface:  #'s         A -  B        C -  E
        F -  H        I -  L         M -  P        R  - T       U  - Z

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