Index
PC hardware projects page
- 24 Line Parallel Interface for the PC - big file in pdf format, you might only need the Rate this link
- 8254 timer/counter board - The schematic, theory of operation, construction tips and parts lists Rate this link
- DAC schematics for PC slot - 8 bit DAC circuit, documentation in russian Rate this link
- Decoder safely drives data-bus buffer - a common way of implementing an I/O decoder for the ISA (or similar) bus Rate this link
- Filtering PC bus POWER Rate this link
- General purpose 48-bit ISA parallel I/O card Rate this link
- ISA bus provides access to serial peripherals - you can easily connect peripherals with serial interface to the ISA bus through an I/O port that latches control and data bits Rate this link
- learn-c.com: Controlling The Real World With Computers - real-world equipment controlling using PC and C from basics to actually providing output to and getting input from the board, includes I/O card circuit plans Rate this link
- POST repeater reads out remotely - power-on self-test card with remote display Rate this link
- PAL powers universal ISA bus interface Rate this link
- P.O.S.T. Diagnostics Card - Whenever a computer boots up, the BIOS does a self-check of the system to verify that all components of the system are operating correctly. As the BIOS works its way through the list of things that need to be checked, it sends out 'messages' which indicate the status of the testing process. These 'messages' are sent out to I/O port 80H. This is where the P.O.S.T. card comes in. It plugs into the ISA expansion bus of the PC and monitors all data sent to port 80H. Each 'message' is a single byte. The P.O.S.T. card reads this byte off the bus and displays it on its 7-segment displays. In this manner, it is possible to observe which test the computer is performing. This is very useful as a diagnostics tool for a non-functional computer because the code associated with the last attempted test is left on the POST card display even after the computer locks up. Rate this link
- Bridge chips help connect host and expansion buses to the PCI bus - many vendors are offering bridge chips to help PCI get on and off the buses of various CPUs Rate this link
- Designing PCI-compliant master/slave interfaces for add-on cards Rate this link
- FPGAS: Implementing the PCI Interface Rate this link
- Treat circuit boards as design components in PCI-based systems - by treating pc-board traces and device loads as components in a transmission line, you can create high-speed PCI-system designs that satisfy the PCI Specification Rev 2.0 Rate this link
- Interfacing to the IBM-PC Parallel Printer Port Rate this link
- Parallel port interfacing made easy Rate this link
- Printer Port interfacing 1 - Schematics for a simple printer port project . Includes code for Visual Basic , QBasic , C and C++. Rate this link
- PC-KITS Parallel Port Tuatorial Rate this link
- 4 - Channel Digital Logic Analyzer and 5 Channel Digital Oscilloscope by using PC Parallel Port Rate this link
- Analog-to-Digital and Digital-to-Analog Conversion via the IBM-PC Parallel Printer Port Rate this link
- BIOS interrupt performs A/D conversion - This flexible conversion technique allows you to use successive-approximation, ramp-type, or other converters by writing the appropriate control software Rate this link
- Circuit loads eight-channel DAC from PC port Rate this link
- Interface a serial 12-bit ADC to a PC - The MAX187 is a 12-bit A/D converter. You can create an interface to this ADC using serial data communications techniques. Analog-to-digital conversion and data transfer from MAX187 require only three digital-I/O lines. You can create a simple interface between the MAX187 and a PC using the computer's Centronics printer port. Rate this link
- Parallel port powers simple A/D interface - uses MAX147 A/D converter IC, can monitor eight channels at 50 samples/sec on a 486-33 PC or one channel at to 400 to 500 samples/sec Rate this link
- Plans for a 4-channel 8-bit analog-to-digital converter for PC Rate this link
- Printer port controls A/D conversion - circuit uses a microcontroller (PIC16C71) as an A/D converter and a data organizer Rate this link
- Printer port hosts precision analog I/O board - 12-bit analog I/O board that plugs into a PC's printer port Rate this link
- ScopeOnPC - ScopeOnPC is a software that uses the PC parallel port and an ADC (Analog To Digital converter) circuit to turn your PC into a full featured oslciloscope. Software is available for DOS and Windows. Rate this link
- Use of an LTC1392 Temperature, Vcc and Differential Voltage Monitor - inexpensive 10-bit A/D converter with the added capability of measuring the temperature of the IC and the value of the nominal +5 V supply Rate this link
- WinScoop - Oscilloscope Program for Windows 3.11 and Windows 95, with hardware connected to the LPT port Rate this link
- Parallel port provides high-resolution temperature sensing - This circuit gives you high-resolution temperature sensing at low cost is by using only one chip attached to the PC's parallel port. The Dallas Semiconductor DS1722 digital thermometer allows measurement resolution as fine as 0.0625?C in digital form and with linear response. The accuracy specification is only 2?C, but you can improve this figure by careful calibration. Rate this link
- 4 - switch control from PC parallel port - controls 4 relays from PC parallel port Rate this link
- BASICs for developing a PC LAP counter - This circuit uses some hardware and BASIC program to make a PC based slotcar lap counter. The circuit has alsso a relay control option. Rate this link
- Kello / ohjelmatietojenn?ytt?j? - four number 7segment display which connects to PC parallel port, documentation in Finnish Rate this link
- LPT-16-0 - 16bit Output Interface for the Parallel Port, check also Rate this link
- Parallel Port Relay Interface example of controlling a relay from the PC's parallel printer port Rate this link
- Parallel Port Servo Controller - gives you 256 different positions over the full range of the servo Rate this link
- PC Printer Port Relay Board - Communicate with the real world via the parallel printer port on your PC. Simply connect printer cable from computer to Centronics connector on relay board. There are 8 relays each capable of switching 12VDC/120VAC @ 10A. Each relay has an LED to indicate when it is operated Rate this link
- Printer port activates CMOS switches - This cost-effective design provides control for CMOS switches without the need for an external power supply. Analog switches such as those in the MAX4663 are ideal for use in low-distortion applications. They are preferable to electromechanical relays in automatic test equipment or other applications in which you need current switching. The CMOS switches use lower power, consume less board space, and are more reliable than electromechanical relays. Rate this link
- Relekortti - PC parallel port relay card, text in Finnish Rate this link
- Stepper motor controlling using PC parallel port - and links to stepper motor documents Rate this link
- Use printer port as programmable frequency generator - A simple and inexpensive circuit and a simple C program are all you need to turn your PC's printer port into a programmable frequency generator. Using a few low-cost and readily available components, the circuit occupies little space and is easily attachable to the printer port. With this circuit you need only enter the desired frequency, and the PC does the rest. The circuit uses a MAX5130 low-power, programmable, 13-bit DAC, IC1; an OP07 buffer; and an AD537 VFC (voltage-to-frequency converter). The PC controls the DAC using a three-wire serial interface. Rate this link
- Eprom Programmer - works with Windows(95) Rate this link
- External Parallel Port devices and Linux - Information on the programming external peripherals connected to parallel port (IDE adapters, tape drives, cameras) Rate this link
- IDE2LPT - PC parallel port to IDE converter based on Altera CPLD, includes circuit board design, drivers available for DOS and WIndoes 9x, text in German Rate this link
- Parallel IEEE 488 interface for the PC printer port - only been tested on an old TTL-style printer port, not known if works with modern ones Rate this link
- Parallel port IDE/ATA interface - according the Rate this link
- WinAmp Matrix Orbital/Crystalfontz/HD44780 LCD Plugin - This WinAmp plugin in combination with a Matrix Orbital LCD / VFD, Crystalfontz or a HD44780 display makes it possible to display the current song name and additional status information on the display. The LCD displays inerface to PC parallel or serial port depending on the LCD model. Rate this link
- Interfacing a Junk Disk 5-1/4 inch Drive with a Parallel Port - This discusses how to interface with the circuitry on a junk 5-1/4 inch disk drive so as to control the stepping motor. Although this discussion focuses on the early full height IBM drives, most of the points are probably common to most other disk drives. Rate this link
- Use a PC to record four-channel waveforms - very simple four channel logic analyzer which connects to PC parallel port Rate this link
- A logic analyzer using the PC's parallel port. - This logic analyzer can Run on Win95 and Win98 and ME using non-interrupted burst acquisition and run on Win2000 NT XP with interrupted acquisition, record up to 8 channels, any parallel port, support sampling at up to 1 million samples per second (depending on your hardware) and record 32768 samples. The software supports save and load recordings to/from disk. Rate this link
- Centronics port generates narrow pulse widths - Variable-pulse-width signals are useful in control circuitry for positioning and holding purposes in robotics and power electronics. Frequently, the need arises for pulses with width less than 1 msec. Delays less than 1 msec are usually not available in most programming languages, so generating such pulses can be a problem. To generate a fractional-millisecond delay you can use a PC's 8254 16-bit timer (Counter 2), which normally controls the PC's speaker. The desired pulse is available at the PC's Centronics port through a buffer stage, which protects the port from overload damage. Rate this link
- DRAM used as camera - zipped file Rate this link
- EPROM emulator - data loading usign PC parallel port Rate this link
- Kello / ohjelmatietojenn?ytt?j? - four 7 segment displays to PC parallel port, text in Finnish Rate this link
- Printer Sharer - will allow two PC's to share one parallel (Centronics) printer without manual intervention Rate this link
- Tricks increase utility of parallel port - In this simple application of the 68HC68 microcontroller's serial-I/O utility, the goal is to configure a simple circuit, driven by any LPT parallel-printer port, which you can use as a remote I/O for a PC. You can independently program each I/O line as either an input or an output. The protocol in this application is an SPI (MISO/MOSI/SCK) type, using synchronous serial communications. Rate this link
- DigiTemp - Digital Temperature Sensor for Linux, DOS and Win95 Rate this link
- A really simple RS232 protocol monitor - very simple circuit which helps serial port debugging Rate this link
- Nuukiaworld - Building instructions and related ideas for Nokia mobile phones. Rate this link
- RS-232C handshake lines transfer data frames - you can use the DTE-DCE handshake using RS-232 Rate this link
- Isolated Full Duplex RS232C Interface - This self powered interface circuit electrically isolates the TxD and RxD lines from the PC serial port and protect the PC from direct connection to hazardous voltages. This can be necessary when the target system works at a completely different voltage level, or when earth loops must be avoided. Rate this link
- Marko M?kel?'s electronics projects: RS-232 Solid State Relay - The hardware is very simple, consisting of a solid state relay, a fuse, a switch and some cables. It is fairly easy to control the RS-232 port from software. You can download the example program as bitbang.zip. It contains the C source code for POSIX termios and Win32 and a Win32 executable. This page has also patches for the VDR softdevice plugin that controls the power to monitor with relay so that the monitor will only be powered on when video is being displayed (video can be started with remote control for example). Rate this link
- Marko M?kel?'s electronics projects: RS-232 Solid State Relay - The hardware is very simple, consisting of a solid state relay, a fuse, a switch and some cables. It is fairly easy to control the RS-232 port from software. You can download the example program as bitbang.zip. It contains the C source code for POSIX termios and Win32 and a Win32 executable. This page has also patches for the VDR softdevice plugin that controls the power to monitor with relay so that the monitor will only be powered on when video is being displayed (video can be started with remote control for example). Rate this link
- 101 AT Keyboard to ASCII Decoder using 68HC705J1A MCU Rate this link
- AT keyboard emulation using PIC microcontroller - keyboard and host side routines Rate this link
- GKOS Keyboard - This page is about how to build an infrared replacement of the PC keyboard and mouse. Rate this link
- Keyboard data-acquisition system is cheap and simple - PIC12C67 based 8 bit ADC circuit which connects to PC keyboard and output PC keyboard keypresses Rate this link
- Keyboard Interfacing Project - a report which shows how to cut the cost of a homebuilt flight simulator by many hundreds of dollars through the use of keyboard interfacing for building custom control panel Rate this link
- KeyBoard/Mouse Focus Project - serial port based box controls the I/O of both keyboard and (serial) mouse ports of up to seven computers Rate this link
- AT89C2051 based hardware keyboard logger - Records user keystroke activity to internal EEPROM memory. Simulates keyboard operation for data retrieving. Schematics, 8051 source code and PC application for data download are provided. Rate this link
- Beyond Logic Universal Serial Bus Pages - information on USB ready microcontrollers, USB drivers and USB protocol analyzing Rate this link
- ATA/ATAPI-6 command specification Rate this link
- CD-ROM audio connectors - This document describes the audio connector pinouts in the CD-ROM drives and circuit to combine audio from two CD-ROM drives to one soundcard input. Rate this link
PC projects
ISA bus cards
PCI bus
PC parallel port
Documents
A/D and D/A conversion
Other measuring applications
Controlling applications
Interfacing to computer hardware through parallel port
Logic analyzers using parallel port
Misc
PC Serial port
ADC and DAC circuits
Serial line monitoring
Serial to parallel conversion
Keypads to serial port
Other
Keyboard
USB
The USB is a serial data-transmission system that uses cables to connect peripheral equipment to PCs. All new computers have two or more USB receptacles, and the predictions are that they will replace most of the legacy receptacles on older PCs. 1.0 specifies 2 forms of signaling transfer rate : Low Speed (1.5Mbits/sec) and the Full Speed (12Mbits/sec). The 1.1 specifications clarified many timing parameters which were grey-areas in the past. However, no huge "functional" improvements were given. Version 2.0 of the USB Specifications it adds a High Speed physical layer of (480 Mbits/sec), the specifications maintains the Low Speed and Full Speed operation. In effect was a handshake protocol was implemented to negotiate into the different speeds, a new High Speed Hub to manage all 3 speeds and a new Enhanced Host Controller to managed the faster bus and new PIDs to efficiently handle USB bandwidth.
The USB standard specifies two kinds of cables and two variations of connectors. High-speed cables, for 12Mbps communication, are better shielded than their less expensive 1.5Mbps counterparts. The cables rated for 480 Mbits/sec are even better constructed. Each cable has an "A" connector on one end and a "B" on the other. "A" connectors go to the upstream connection while the "B" version attaches downstream. Since the two types are physically different it's impossible to install a cable incorrectly. Ready made USB cables are available in a wide variety of length ranging from .5 meters to 5 meters. 5 meters (about 15') is the maximum cable length allowed by the USB specification. USB maximum cable distance is 16 feet. USB hubs cab be used as repeaters. The USB cable consists of one twisted pair for data and two untwisted wires for powering downstream appliances. Specifically, a full-speed cable contains a 28-gauge twisted pair, an untwisted pair of 28 to 20 gauge power conductors (typically red +5V, black ground), an aluminized polyester shield, a drain wire, and an overall 65% (minimum) copper braid. Nominal impedance for the data pair is 90 ohms.
Though physically configured as a tiered star, logically (to the application code) a direct connection exists between the host and each device. USB bus can supply +5V power to devices connected to them. Though nominally +5V, the spec allows for quite a bit of variation in this; designers should allow for as little as about 4V. A peripheral that draws up to 100ma can extract all of its power from the bus wiring all of the time. Higher current requirements are trickier; if the device requires less than 500ma, and if the upstream host or hub can provide that much power (which is optional), the device can be bus-powered if at power-up time, during system configuration, it consumes less than 100ma. If the device needs more than a half-amp, then it must have its own power supply. USB system has power managing built in. USB hosts and hubs manage power by enabling and disabling power to individual devices to electrically remove ill-behaved peripherals from the system. Further, they can instruct devices to enter the suspend state, which reduces maximum power consumption to 500 microamps (for low-power, 1.5Mbps peripherals) or 2.5mA for 12Mbps devices.
USB is a complex standard that requires an enormous amount of software support, both on the firmware side and in the host computer. Most host-end connections, for better or worse, will be PCs running a Microsoft operating system. USB is not supported at all in DOS, Windows 3.x, or Windows NT. All Windows 98 releases include a full set of drivers for common USB applications. Windows 2000 and XP has this same USB support too. A USB driver is a difficult beast. The good news is that in many cases the drivers provided with Windows will handle even your custom peripheral. Windows, as well as the USB specification, segments drivers into "classes," where hardware that falls into a single class shares similar interfaces. A class defines a baseline specification for a given set of capabilities; all devices in a class require comparable types of software support. An example is the human interface device (HID) class, which supports devices like mice, joysticks, and keyboards.
If you plan to build an USB device you should use parts and or interface ICs that are designed to be used with USB interface. USB interface is something you can't easily built from discree general purpose components. For do-it-your self people USB is not the friendliest environment to work with. First the USB itself is quite complicated to implement and second problem are the drivers. For building your own USB peripherals you need to conform to a generic USB driver class, such as Human Input Device class, Mass storage class, etc. or you need to write a WDM driver for yourself - not easy. USB parts are rather hard to categorize, but fall generally into three camps: host-side USB controllers (which live inside the PC, and are probably of little interest to ESP readers), devices designed as stand-alone USB peripheral controllers (like a smart UART, these chips handle communications but you'll need another microprocessor as the brains of your device), and versions of popular processors that include a USB interface. Beyond these three categories, some vendors offer specialized parts, such as USB camera controllers, audio devices, bridges that link USB to other buses, and specialized HID controllers. Development tools are as important as chips and code.
CD-ROM projects
A often asked project using PC CD-ROM drive is how to use a PC internal CD-ROM drive as stand-alone CD player. Basically a normal PC CD-ROM need well regulated +5 and +12V to operate. You need a suitable power supply to supply this power to the drive (I quess that 1-2 amperes of each power is enough for most drives, usually the faster the drive is, more power it takes). The audio on normal CD-ROM drive is available on front panel headphone connector for headphones and on the back of the drive as line level signal. Controlling the playback of the CD generally works with the front panel buttons when you apply just the power to drive (no need to connected the IDE connector to anythign on most drives). In case your drive does not have all the control buttons you need on the front panel, things get more complicated. The idea of controlling the drive through the IDE connector is the following: You are sending some control "words" to the IDE connector and the drive is reacting to that word by playing, stopping, skipping. The ATAPI standard specifies those commands. In normal PC use, your PC hardware and CD-ROM driver software sends those commands to your drive. If you want to use something else than normal PC for controlling, you need some for of microcontroller to generate the necessary signals to IDE bus and sending the needed commands (you need to know how to program microcontroller and understand the IDE/ATAPI specifications to be ablr to implement this).
MP3 players
This section lists MP3 players, both PC based and non-PC projects.
Other related pages
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