View Full Version : Would this work with a laptop?

11-29-2010, 08:14 AM
First off I would like to say hello for I am new here. I am just finishing up with the construction of David Steele's 25x25 machine and am very close to hooking it up for trial runs. I've been looking for a used desktop to put in the shop but not wild about the idea since it would take up a lot of room in a space that is already limitied for the amount of work I am doing in there. I have read the numerous comments that laptops will not work well with these machines but ran across this product...

TRENDnet | Products | Wireless Print Servers | TEW-P1PG (http://www.trendnet.com/products/proddetail.asp?prod=100_TEW-P1PG&cat=25)

It says the input voltage is 5V but doesn't say anything about the output voltage (for the arguement that the output voltage of laptops are the problem). My question is would this be worth spending $80 on to see if it works or would it most likely be a bust and I should go straight to the desktop. I could jump it right on my existing wireless network and it would make things very convenient if it would work. Thanks in advance for any input and advice.

FYI, for any beginners looking to build a machine Steele's plans where great! Very well thought out and straight forward. I went from someone who didn't know people where building there own CNC's to construction in about a week and had no real problems throughout the build.

11-29-2010, 08:56 AM
No, that won't work. It needs to be a real parallel port on the motherboard, or a PCI card.

11-29-2010, 09:59 AM
Well, for most cards, and most "direct port communications", software, it will not work. However, it will work if you use something like an arduino, or pic-microcontroller, or an industrial controller.

A majority of the controllers are just driver-controllers, not actual controllers. The computer is the controller, and the driver-controller just relays the signal from the computer to the driver. (There is no real control in a controller. At the most, a buffer and joystick inputs.)

That is why many USB to PP/LPT will not work. The computer needs full 5v, and immediate INPUT/OUTPUT feedback. Since there is no real "controller" in most setups, there is no real "language" to communicate, unlike a printer, which has both a real controller and a language for communication.

However, many industrial controllers, like printers, have actual controllers and languages. They require additional software to run, or drivers and language code, such as printer-server language.

Eg, the computer says...

Pin 2, on
Pin 3, off
Pin 4, on...

That is the extent of these simple devices... That pulses one pulse on motor 2, and 4...

Printers use language, and pins 0-8 = data out... the data says...

Move print-head to position 234523
Print black 230
Print magenta 23
Print cyan 68
Print yellow 127...

In essence... the correct answer is, yes, it is possible, with the correct devices. But most devices used here, are not the correct devices with which that is possible.

11-29-2010, 07:49 PM
Thanks fellas...that's what I needed to know. Used desktop it is.