Parallel Port Controller

Parts list:

DB25 Male Connector

ULN2003 Integrated Circuit

8 12V relays

Technical Specifications:

Power supply voltage: 12V

Regarding parallel port controllers

This is a very easy and fun project that allows you to control up to eight external devices through a computer's parallel port. For example, you can control various appliances such as lights, computers, printers, televisions, radios, music systems, air conditioners, fans, garden sprinklers, and anything else you can think of, all through your computer.

You can do a simple test by connecting an LED directly to ground and any pins 2 through 9 of the parallel port. The voltage on the parallel connector is approximately 4.5V, but it will drop to about 2V once the LED is connected. You can use a 100-ohm resistor if needed, but it's not necessary due to the very low current.

Parallel port controller software

Precise LC table

Build your own precise LC meter (capacitance and inductance meter) and start making your own coils and inductors. This LC meter can measure very small inductances, making it a perfect tool for building a wide variety of RF coils and inductors. The LC meter can measure inductances from 10 nanohenries to 1000 nanohenries, 1 microhenry to 1000 microhenries, 1 millihenry to 100 millihenries, and capacitances from 0.1 picofarads to 900 nanofarads. The circuit includes an autoranger and a reset switch, and produces very accurate and stable readings.

PIC voltmeter

This voltmeter measures voltages from 0-70V or 0-500V with a resolution of 100mV, and current consumption from 0-10A or higher with a resolution of 10mA. It is a perfect complement to any power supply, battery charger, and other electronic devices for monitoring voltage and current. The meter utilizes a PIC16F876A microcontroller and a 16x2 backlit LCD.

60MHz frequency counter

The frequency counter measures frequencies from 10Hz to 60MHz with a resolution of 10Hz. It is a very useful benchtop testing device for testing and identifying the unknown frequencies of various devices, such as oscillators, radio receivers, transmitters, function generators, crystals, etc.

1Hz - 2MHz XR2206 Function Generator

The 1Hz - 2MHz XR2206 function generator produces high-quality sine, square, and triangular waveforms with high stability and accuracy. The output waveform can be amplitude and frequency modulated. The output of the 1Hz - 2MHz XR2206 function generator can be directly connected to a 60MHz counter to set a precise frequency output.

BA1404 High-Fidelity Stereo FM Transmitter

Own your own radio station! The BA1404 high-fidelity stereo FM transmitter broadcasts high-quality stereo signals in the 88MHz-108MHz FM band. It can connect to any type of stereo audio source, such as iPod, computer, laptop, CD player, Walkman, TV, satellite receiver, cassette deck, or other stereo system, to transmit stereo audio with excellent clarity throughout your home, office, yard, or campground.

USB input/output board

The USB IO board is a tiny, amazingly small development board/parallel port alternative using the PIC18F2455/PIC18F2550 microcontroller. The USB IO board is compatible with Windows/Mac OSX/Linux computers. When connected to Windows, the IO board will appear as an RS232 COM port. You can control 16 independent microcontroller I/O pins by sending simple serial commands. The USB IO board is self-powered by the USB port and can provide up to 500mA of current for electronic projects. The USB IO board is also compatible with breadboards.

ESR meter/capacitance/inductance/transistor tester kit

ESR meter kit is an amazing multimeter that measures ESR values, capacitance (100 picofarads - 20,000 microfarads), inductance, and resistance (0.1 ohms - 20 megohms), testing many different types of transistors such as NPN, PNP, FET, MOSFET, thyristors, SCR, Triac, and many types of diodes. It also analyzes transistor characteristics such as voltage and gain. It is an indispensable tool for troubleshooting and repairing electronic equipment by determining the performance and health of electrolytic capacitors. Unlike other ESR meters that only measure ESR values, this one measures both the ESR value and capacitance of a capacitor simultaneously.

Audiophile headphone amplifier kit

This audiophile headphone amplifier kit includes high-quality audio-grade components such as the Burr Brown OPA2134 op-amp, ALPS volume control potentiometer, Ti TLE2426 rail splitter, ultra-low ESR 220µF/25V Panasonic FM filter capacitors, high-quality WIMA input and decoupling capacitors, and Vishay Dale resistors. An 8-DIP mechanical IC socket allows the OPA2134 to be interchanged with many other dual op-amp chips, such as the OPA2132, OPA2227, OPA2228, dual OPA132, OPA627, etc. The headphone amplifier is small enough to fit in an Altoids case and, due to its low power consumption, can be powered from a single 9V battery.

Arduino Prototype Kit

The Arduino Prototype is an amazing development board fully compatible with Arduino Pro. It's breadboard compatible, allowing for rapid prototyping by simply plugging it into a breadboard, and it has VCC and GND power pins available on both sides of the PCB. It's small, power-efficient, yet customizable with an onboard 2x7 through-hole board for connecting various sensors and connectors. The Arduino Prototype uses all standard through-hole components for ease of construction, with two hidden under the IC socket. Board features include a 28-pin DIP IC socket, a user-replaceable ATmega328 microcontroller pre-brushed with Arduino bootloader, a 16MHz crystal resonator, and a reset switch. It has 14 digital input/output pins (0-13), 6 of which can be used as PWM outputs, and 6 analog inputs (A0-A5). Arduino sketches can be uploaded via any USB-serial adapter connected to a 6-pin ICSP female connector. The board operates on 2-5V and can be powered by batteries such as lithium-ion batteries, two AA batteries, an external power supply, or a USB power adapter.

200-meter 4-channel 433MHz wireless RF remote control

Being able to wirelessly control various appliances inside and outside your house is a huge convenience that can make your life easier and more fun. RF remote controls offer a range of up to 200 meters/650 feet, with numerous uses for controlling different devices, and they can even work through walls. You can control lights, fans, air conditioning systems, computers, printers, amplifiers, robots, garage doors, security systems, motorized curtains, motorized blinds, door locks, sprinklers, motorized projection screens, and anything else you can imagine.