Interfaces

So you've read about my Computerized Room or have seen those nifty home automation products advertised in the back of electronics magazines? Or perhaps someone you know has done something similar. At any rate, you have decided to try it yourself. The first thing I will say, however is that it is not cheap.

This adaptor will capture plots or prints of your GPIB instrument to your PC through the serial port. It fills the need of anybody who has a test instrument with the GPIB port and likes to get the screen dump on his PC without any GPIB card. Project based on a PIC16F628A microcontroller.

This board is designed specifically to control the 5-motor Robot Arm sold by Baycom Technologies. It has no input facilities, but it is less expensive than combining the I/O Board with the Relay sub-Board. If you need lots of relays and no input, this is the way to go.

Several years ago, actually many years ago, I took a university subject in which we had to write code to control a simple computer controlled train set. If you've never seen such a beast, let me assure you that it's one of the most fun projects that you could imagine working on in a university electrical engineering environment. This was the genesis of a computer controlled layout of my own.

Looking for the optimum non-volatile memory product for your system that requires a small footprint, byte level flexibility, low power, and is highly cost effective? Serial EEPROM technology is one of the non-volatile memory technologies that has emerged as a leading embedded control solution. Unfortunately, most system designers are not aware of the serial EEPROM benefits. Also, the supporting documentation in databooks is most often not adequate due to incomplete or ambiguous information. As a result, the system designer often selects a non-volatile solution that does not meet his requirements, or, the designer must face a more complicated design-in with a serial EEPROM.

It is very interesting and convenient to be able to control everything while sitting at your PC terminal. Here, a simple hardware circuit and software is used to interface a 7-segment based rolling display. The printer port of a PC provides a set of points with some acting as input lines and some others as output lines. Some lines are open collector type which can be used as input lines. The circuit given here can be used for interfacing with any type of PCs printer port. The 25-pin parallel port connector at the back of a PC is a combination of three ports. The address varies from 378H-37AH. The 7 lines of port 378H (pins 2 through 8) are used in this circuit to output the code for segment display through IC1.

This is one of the simplest circuit for a PC parallel port based DLA. The Circuit is mainly used to protect the port which is fabricated on the motherboard itself. The IC 74LS04 is an inverter and acts as a buffer. The Zener is used for undervoltage and overvoltage protection. If a voltage > 5V appears on the input, The buffer will not transmit this voltage to the PC. In the case of a voltage < 0V, The Zener will break down and 0.7V will appear at the input, hence again protecting the PC.

This page gives some information on a PC based IR remote control system I've developed for computer control of TV, video, satellite and hifi equipment etc. I have used an IBM compatible, so the software here is for such a machine, however I guess that it is straightforward (perhaps easier) to implement this on another type of machine.

This is the first interfacing example for the Parallel Port. We will start with something simple. This example doesn't use the Bi-directional feature found on newer ports, thus it should work with most, if no all Parallel Ports. It however doesn't show the use of the Status Port as an input. So what are we interfacing? A 16 Character x 2 Line LCD Module to the Parallel Port. These LCD Modules are very common these days, and are quite simple to work with, as all the logic required to run them is on board.

This system, composed of two opto-insulated circuits, allows the data transmission per infra-red network device between two computers. For example, someone can transfer his files starting from his desktop computer to his laptop computer without using any cable. How? By using infra-red diodes. We have to connect a circuit to the 10/100 Mbps network card of both computers by using a very small network cable (can be smaller than 10 cm). One of the two extremities of the cable must be removed to allow the wire connections. We must pay attention when we do the connections.

The goal of this project was to use infrared technology to remotely control a CD-ROM drive with an audio CD. The idea was developed by Matt Treiber in an attempt to make it more convenient to play audio CDs on his computer. This device will permit the basic functions of the CD player application such as play, next track, previous track, seek-forward, seek-reverse, and stop to be remotely controlled. The device will consist of an infrared detector and demodulator and the rest of the project will be implemented in the software.

This page describes my home-built ICOM CI-V interface. In order to connect most all ICOM radios to a computer, an additional interface is required. The interface bridges the gap between the RS-232 electrical levels used by the computer serial port, and the open collector shared bus used by the ICOM radios. The interface, therefore, is not much more than a level converter.

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).

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.

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.

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 together with his collection of MIDI keyboards and synthesizers. Of course, I wanted to build something that could end up as a finished commercial product.

Microwaves are maybe, one of the greatest discovers of the 20’th century. With a vavelenght between 30 cm and 3 mm and a power between 1 mW and 500 KW are practically used in all fields from medicine to industry. Microwave thermal and chemical tratments are well known for the high efficiency, with 3 to 1000 times greatest then conventional process because of direct energy transfer into materials and selectivity compounds heating following dielectric permittivity parameters of the materials involved in reaction or in the treatment (equation 1):

The circuit in Figure 1 provides a novel method of reading the pulse train using an Atmel (www.atmel.com) AVR processor, from a typical radio-controlled receiver, and to determine the velocity of a motor. To capture the pulse train from a typical receiver, you need an external interrupt that triggers based on a rising and a falling edge.

This is a simple IR receiver circuit which plugs into a serial port of a computer. Okay, there are many other circuits of this kind, and most of them are even simpler, but this circuit has two major advantages: (1) it uses an Atmel AVR RISC microcontroller (an AT90S2313) instead of the usual PIC microcontroller and (2) it uses a Maxim MAX232 for the generation of valid RS232 levels.

Embedded-system designers are aware of the difficulties in connecting a µC to a large number of peripherals, such as A/D or D/A converters. An interesting possibility, one that you might overlook but definitely should consider, is to use an audio DSP, such as the DSP56004/7/9 from Motorola (Phoenix). These devices contain two audio serial receivers, three audio serial transmitters, and a serial-peripheral-interface port. You can easily program these various serial inputs and outputs to provide other application-specific inputs and outputs, as well as simple repetitive signals, such as convert or frame-synchronization signals.