Machsupport Forum

Mach Discussion => Mach4 General Discussion => Topic started by: tony978 on April 27, 2019, 08:44:12 AM

Title: ess probe sanity check
Post by: tony978 on April 27, 2019, 08:44:12 AM

so I'm have an ess and a c25 with probe . It is powered by a 2 amp 5 volt supply , both ess and c25 are powered by it . I'm not sure why when I connect probe signal pin 13 port 2 to ground it doesn't show tripped in mach . The probe checks out with a meter .  the ess and mach are configured for that pin name to probe . anything I missed ?

Title: Re: ess probe sanity check
Post by: MN300 on April 27, 2019, 09:00:35 AM

The CNC4PC C25 manual asks for a 4.7K pull-up resistor from the probe input to +5V, have you installed one?

Title: Re: ess probe sanity check
Post by: tony978 on April 27, 2019, 09:12:51 AM

That is just the jumper that is moved from what I understand or could be the issue

Title: Re: ess probe sanity check
Post by: MN300 on April 27, 2019, 09:33:01 AM

If there is a pull-up resistor connected the input will measure 5V with the probe not grounded and 0V when the probe is grounded.

Title: Re: ess probe sanity check
Post by: tony978 on April 27, 2019, 09:37:19 AM

It just decided to work after pulling the probe apart and reassembling.  I still don't get why jumping pins to ground wouldn't work ?

Title: Re: ess probe sanity check
Post by: reuelt on April 27, 2019, 02:58:03 PM

Quote from: tony978 on April 27, 2019, 09:37:19 AM

It just decided to work after pulling the probe apart and reassembling.  I still don't get why jumping pins to ground wouldn't work ?

The C25 inputs pins (unlike many BOBs) are ACTIVE HIGH types - meaning they are already grounded with 4.7K resister internally. Jumping pins to ground wouldn't work, You have to jump pins to 5V (& not Gnd) for it to work.
See Attached,
So

Title: Re: ess probe sanity check
Post by: tony978 on April 27, 2019, 03:01:07 PM

Good to know ! All is working now !