New computer = weird problems

[rbjem]

My limit/home switches are acting very bizarre.   I have been struggling with this issue for half the day, doing searches, tweaking, testing, repeat but no luck.

I bought a new (to me) computer today and formatted the HDD and installed XP Pro, drivers and Mach3 R3.043.022 lockdown version. I did this because my old computer would freeze every so often (no bluescreen, just completely lock up) and it got to the point where I couldnt handle it anymore.  I have set the parallel port in the bios to EPP mode.

I am using a different Mach3 version, (I was previously on R3.042.040) but am using the same .xml config file.  I am using hall sensor switches and my BOB is from candcnc using their table IO board.

The problem is that the LEDs on the diagnostics screen are showing my home switches going off and on sporadically which is causing limits to trigger when I home it.  My BOB is showing a constant signal, but the diagnostics screen is definitely not showing that.  I have made a video to show what is happening (I disabled limits for this).

http://youtu.be/mqcbvgfKKKI

My original configuration had debounce values at 25 with no problems, and I have incrementally tried up to 10,000 but nothing solved the underlying issue. 

Does anyone have any idea what could be causing this problem?  I will reinstall Mach3 tomorrow unless someone has a better idea.

Thanks,
rbjem
 

[Hood]

Have you changed any wiring?
Tried using the same version of Mach as you previously had?

Hood

[rbjem]

I have not touched any wires.

[Hood]

and did you try the older version of Mach?
Could your BOB require 5v and your new PP is 3.3v?
Hood

[stirling]

The problem is that the LEDs on the diagnostics screen are showing my home switches going off and on sporadically which is causing limits to trigger when I home it.  My BOB is showing a constant signal, but the diagnostics screen is definitely not showing that.  I have made a video to show what is happening (I disabled limits for this).

You probably wouldn't see your BOB LED flashing because it'll be too quick. The "LEDs" on the screen are only updated 10 times/sec so you're kind of seeing a slow motion version of reality. Trust Mach - if they're flashing (which they are) then the signal IS intermittent. In fact if you look at your vid when you look at the BOB LED you CAN actually see it flash once when you jog onto your switch which if all was well it wouldn't do. I reckon your on the bounce point of your switch. Debounce of any value is not going to help if your switch is constantly bouncing. What happens if you jog up just a tad more onto the switch? does your screen LED settle? I'm gessing it's NOT noise otherwise your on screen LEDs would flash even when you were miles away from the switch.

[rbjem]

and did you try the older version of Mach?
Could your BOB require 5v and your new PP is 3.3v?
Hood

Hmm, this is an older PC (~6 years old), so I am leaning away from it using 3.3V, but ill check it with my multimeter. I will try the older version later today as well. 

[/quote]

You probably wouldn't see your BOB LED flashing because it'll be too quick. The "LEDs" on the screen are only updated 10 times/sec so you're kind of seeing a slow motion version of reality. Trust Mach - if they're flashing (which they are) then the signal IS intermittent. In fact if you look at your vid when you look at the BOB LED you CAN actually see it flash once when you jog onto your switch which if all was well it wouldn't do. I reckon your on the bounce point of your switch. Debounce of any value is not going to help if your switch is constantly bouncing. What happens if you jog up just a tad more onto the switch? does your screen LED settle? I'm gessing it's NOT noise otherwise your on screen LEDs would flash even when you were miles away from the switch.

That did cross my mind, but when I jog higher up on the switch it does not settle down.  Im just confused since it worked as it should two days ago, and now there's problems.  All I did was plug the parallel cable into a different computer. 

I'm hoping a reinstall fixes it. If not, I may try a PCI parallel port card I have in another computer and see if its the new motherboard causing the issue. 

[Hood]

Thinking about it the 3.3v port should be fine with inputs anyway.
I couldnt view your vid, well could but no sound so wasnt sure exactly what was going on but from what you and Ian are saying its just as you get to the switch that the issue happens? If so then definitely a bad switch, whether the contacts are dirty or they are bouncing I wouldnt like to say but dirty contacts do sound likely as low voltages are not the best for switches.
Hood

[rbjem]

Also, all of my home switches (X,Y,Z,A) do it, I only used the Z to illustrate what was going on. 

The vid just shows the LED on the diagnostics screen jittering, I jog the Z so the home is on, then off, then on.  Then do the same while looking in the control box.  There's no contacts, so they shouldnt be "dirty", and I am fairly certain that the voltage is sufficient. The last time I checked the switches were seeing ~13V which was about a month ago, but I will check again.

Thanks for the replies, they are giving me new ideas to investigate. 

[rbjem]

Just an update: 

I reinstalled Mach3  to the version I was using before.  Didnt work

I installed a PCI PP card that I use to run my mini-mill on another computer.  Didnt work

I put back the old comuter (with a fresh XP and the lockdown version of Mach3, which unfortunatley, I am unable to check with my original install that I know worked correctly). Didnt work.

 

I will check voltages now...

[rbjem]

Ok, I checked the voltage the swicthes are seeing,  15.5V.  They are rated to operate between roughly 5-30V.  

I also tested the signal wire of the X and it is acting sporadic.  So I unplugged the signal lead (my switches have 3 leads; hot, ground, and signal) and put an 3mm led on the signal wire to light up when I put a magnet near my switches.  As far as I can tell, the led is on constantly which indicates to me that the issue is not the control box wiring (which has been working no problem for a month).  

Is there a better test than an led to see if the signal is bouncing high and low? According to thr Mach3 diagnostic screen the switches jump high to low relatively slowly, I would estimate they bounce about every 0.5 seconds, which I would think is well within the response time of an led and a resistor.

Any ideas?