Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Kristin D on April 07, 2008, 08:48:44 PM

Title: First post, LPT and limit questions
Post by: Kristin D on April 07, 2008, 08:48:44 PM
Hi,

I have a HobbyCNC Pro board I am going to setup with Mach3, right now I am awaiting steppers and driver chips as I got this board 2nd hand and it seems all three chips were blown. I am setting it up with a E-Machines Eslate laptop and wondering if that is where my difficulties lie, I've seen some comments elsewhere that laptop printer ports may not be full voltage but I don't feel like pulling out another big PC, monitor, keyboard and mouse.

Anyway I hooked a momentary n.o. switch to the board, went to Config, ports & pins, inputs and tried the autoconfigure thing with no reaction. I can see there is +5 on the pin 10,11,12,13 &15 and it switches low when I depress the switch as measured with a DVM. There is a note somewhere on that screen that says "you may not have the port configured corectly" OK how do I configure the port, is this refering to the device properties in Windows or some setting in Mach? Pretty sure I have a 25 pin cable as I had it marked ser/par and it has DB25 M/F connectors.

Well I am sure to be back with more questions.

Kristin

Title: Re: First post, LPT and limit questions
Post by: jimpinder on April 08, 2008, 04:14:02 AM
If this is just out on the workbench then you can do a lot with it.

First - check that you have five volts coming out of the port. Pins 2 to 9 carry the axis signals and you can check the voltage on any of the "dir" pins as you change direction. Should be 0v one way, and +5 in reverse

To put a signal into the computer fasten a NO switch between pins 10,11,12,13 or 15  and one of the ground pins (18 - 15)
You must configure your Ports and Pins/Inputs correctly and show X and Y limits on say pins 10,11,12 and 13 and a Z limit on 15.
You want to tick "active low" - in other words the switch is active when the input is grounded. If you switch to active high, they will show as on all the time until you switch the switch.

If you then go to the diagnostics page - all the inputs are listed there and if you switch your switch you should see the leds light up - depending on which wire you have connected.
Title: Re: First post, LPT and limit questions
Post by: Kristin D on April 08, 2008, 09:53:07 PM
I just checked and it looks like I suspected that the laptop only has a 3V output, guess it's time to drag out another PC, Keyboard, Monitor and mouse arrg, well I really didn't want the laptop anywhere around swarf anyway but thought I could use it for setup testing. I did go pin to pin and my cable is 25 wire straight through as I thought.

Not sure what the other PC is, I am pretty sure it's a P something chip but not much MHz wize, it was a freebie loaner when my last one blew up. What is the minimum CPU and Frequency needed to run with?

Kristin
Title: Re: First post, LPT and limit questions
Post by: Glenn on April 08, 2008, 10:31:15 PM
Hi Kristin,
  1 gig pentium 4 should get you going, My Dell  laptop is 996mh
pentium 3, and it almost always works... the graphics are too slow,
 and it is slowww when Lazycam is processing a new g-code ,so
if you have an old dell dimension desktop with 1.6gh or higher pentium 4
you should be good to go. My desktop  dell is very stable.
  Good Luck,
    Glenn
Title: Re: First post, LPT and limit questions
Post by: Kristin D on April 08, 2008, 11:10:32 PM
Looks like I am SOL, I just went to take a look at the PC, it does say Pentium on the cover but does not even have a USB port! It was a loaner I used for one week waiting on another to arrive so it looks like a candadate for the recycle yard, perhaps I can find a newer one there! Can't even try it as it would take the next 24 hours to download Mach with dialup.

Kristin