Hello Guest it is November 20, 2019, 09:41:56 AM

Author Topic: Can’t get Probe to Work  (Read 9494 times)

0 Members and 1 Guest are viewing this topic.

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: Can’t get Probe to Work
« Reply #40 on: March 02, 2016, 01:53:59 PM »
so that's all good. The only thing not panning out is the pullUP resistor.

Please switch your meter to resistance and check that resistor.

gotta go (again)

Offline kolias

*
  •  1,011 1,011
    • View Profile
Re: Can’t get Probe to Work
« Reply #41 on: March 02, 2016, 02:21:43 PM »
The meter shows a resistance of 121

Can I use a larger / smaller resistance from the ones i have?
Nicolas

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: Can’t get Probe to Work
« Reply #42 on: March 03, 2016, 04:07:56 AM »
I can't see the point - 121 should pull up to around 4.8V and you're unable to read that so I'm lost I'm afraid. Also the 120 Ohms is already going to pull around 40mA when the pin is grounded.

I'm afraid I'm going to have to give up Kolias.

TBH though - I'd consider binning that BOB. The design IMO is complete crap. The way they suggest implementing tool touchoff on page 11/14 says it all for me.

Offline Tweakie.CNC

*
  • *
  •  8,005 8,005
  • Super Kitty
    • View Profile
    • Tweakie.CNC
Re: Can’t get Probe to Work
« Reply #43 on: March 03, 2016, 04:47:56 AM »
Well Gentlemen, I have been following with great interest and I think you may have given this it’s best shot. This self-same issue with the C10 BoB has, to my knowledge, come up twice in the past and neither time was it resolved in a satisfactory manner.

I really thought that the passive 120R would do the trick but it looks like an active solution – perhaps a simple inverter or opto-isolator may be required if the C10 is to be used (short of attacking the circuit board and removing the damn pull-down).

Overall, I think replacing the C10 with something better may be the way forward.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: Can’t get Probe to Work
« Reply #44 on: March 03, 2016, 05:01:02 AM »
LOL - I wasn't aware this had cropped up before. (you held that one back Tweakie - you #@%$£)  ;D

You're thinking along the same lines as me re: the active approach. However, for the life of me I can't see why the 120 isn't pulling it up.

Also - if it were me I'd do exactly what you suggest - i.e. attack that useless piece of junk with a soldering iron and remove the pull downs.

Might be more fun though for Kolias to soak it in lighter fuel and torch it on youtube - I for one would hit that.

Offline Davek0974

*
  •  2,580 2,580
    • View Profile
    • DD Metal Products Ltd
Re: Can’t get Probe to Work
« Reply #45 on: March 03, 2016, 05:39:44 AM »
See if it Blends ;)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Tweakie.CNC

*
  • *
  •  8,005 8,005
  • Super Kitty
    • View Profile
    • Tweakie.CNC
Re: Can’t get Probe to Work
« Reply #46 on: March 03, 2016, 05:43:10 AM »
If it's any help I think that the C1G was the preferred replacement - it is basically the same BoB but allows individual pull-up / pull-down on the inputs so they can each be set as required.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline stirling

*
  • *
  •  2,188 2,188
  • UK
    • View Profile
    • www.razordance.co.uk
Re: Can’t get Probe to Work
« Reply #47 on: March 03, 2016, 06:08:15 AM »
I'm sure plenty will disagree and I know it's not for everyone but why buy a BOB in the first place?

1) a packet of resistors will cost you less than a penny - that's pullups sorted.
2) a DB25 will cost you less than a quid - you've built everything else - how hard can it be to learn to solder? or even easieer get an IDC DB25
3) You don't need optos - any driver worth buying will already have them. In fact a BOB with optos is usually a PITA - you don't want to be driving optos (in the drive) with optos (on the BOB).

« Last Edit: March 03, 2016, 06:18:11 AM by stirling »

Offline Davek0974

*
  •  2,580 2,580
    • View Profile
    • DD Metal Products Ltd
Re: Can’t get Probe to Work
« Reply #48 on: March 03, 2016, 06:20:57 AM »
Probably because its easy - the board is ready and tested and simple to mount.

I guess if you are building machines daily then you could have your own board made at a fraction of the cost, but when that cost is what ? £10 £20? It seems pointless bothering to build it yourself.

I have used three BOBs so far and all have worked fine, no odd issues with pull-up or down yet, and all have been opto isolated ones. Plus you get the relay and its associated snubber diode etc, nice easy screw terminals, the list goes on - its just easy thats all :)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline kolias

*
  •  1,011 1,011
    • View Profile
Re: Can’t get Probe to Work
« Reply #49 on: March 03, 2016, 09:01:39 AM »
Thank you stirling for the excellent help. The C1G looks a good alternative but at this stage I have to decide if I should go for it.

I have no problem soldering but it’s my knowledge of electronics which is almost a big zero and I can never grasp it
Nicolas