Posts tagged ‘Serial Port’

Building an Auxiliary Display

I wanted to be able to check my web server’s statistics periodically but did not want having to log on ever time when I wanted to do so. The simplest way to achieve this is to have the computer monitor on and run a server statistics program that outputs the information onto the screen. Continue reading ‘Building an Auxiliary Display’ »

Arduino Serial Using LT1780

Most of the recent Arduino and compatible boards use some kind of USB to UART hardware (e.g. FT232RL in Arduino Duemilanove and Atmega8U2 in the latest Arduino Uno) for interfacing with computer USB ports. Since ATmega328 has native UART support, building an Arduino that interfaces with the serial port (RS232) directly is arguably much easier. Continue reading ‘Arduino Serial Using LT1780’ »

An Isolated MOSFET Serial Port Relay Controller

Using DTR (data terminal ready) and RTS (request to send) pins of a PC serial port (RS-232) without actually using the serial data pins, we can interface at least two relay devices with a computer. Windmeadow Labs has an excellent article on how to achieve this using a bipolar transistor (BJT). Here I will show you a similar relay control circuit built using an opto-isolator and a MOSFET. Continue reading ‘An Isolated MOSFET Serial Port Relay Controller’ »