Computers & Mobile Technology
HOW TO – Controlling a relay and motor with a serial port…

SerialChad writes “For a while I have wanted to control things with a serial port. It was pretty easy to control a relay with a serial port. With a standard serial port you can control 2 relays. (with a parallel port you can control 8 relays, but I don’t have a parallel port on my system). A standard PC serial port has 9 pins. Pin 4 – DTR (data terminal ready) and Pin 7 – RTS (request to send) can be used to control a relay. These two ports don’t actually send data. They are used to signal the other device to tell it when to send data.” Here’s the HOW TO – Link.

2 thoughts on “HOW TO – Controlling a relay and motor with a serial port…

  1. There’s a great book for this stuff, Controlling the World with your PC, by Paul Bergsman. I loved this book when I was a young tinkerer (alas I have much less time for tinkering these days, which is why I live vicariously through Makezine.) Mr. Bergsman also used to write for Circuit Cellar, I think. The book has general tips for interfacing with the parallel port, as well as designs for driving LEDs, relays, stepper motors, and lots of other stuff. Great fun!

Comments are closed.

Tagged

current: @adafruit - previous: MAKE, popular science, hackaday, engadget, fallon, braincraft ... howtoons, 2600...

View more articles by Phillip Torrone