End stops not working?

Hey guys,

Just finishing it up and you all have been so much help so far.

I am trying to wire up the endstops, well I think they are wired up. I am using mechanical end stops with Sanguinololu electronics. I hooked them up like it says in the wiki. I hooked them to common and NO, and then used the two outside pins on the board.
I did what it says and in the Sprinter firmware I changed this:
//// Endstop Settings
#define ENDSTOPPULLUPS // Comment this out (using // at the start of the line) to disable the endstop pullup resistors
// The pullups are needed if you directly connect a mechanical endswitch between the signal and ground pins.
const bool ENDSTOPS_INVERTING = true; //set to true to invert the logic of the

I tried commenting out #define ENDSTOPPULLUPS but that didn't work either. Do I need to put the resistors in or am I just making a mistake with the firmware?
When I load any changes in the endstop settings to the board, the movement of the steppers changes and only moves in one direction, then it won't move at all. If I leave it at the defaults, (inverting is false) they operate properly, They just don't stop if they hit the endstop.

Thanks again reprappers!

You need to invert the direction of the endstops.

---

FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

Is that the same as this statement?
const bool ENDSTOPS_INVERTING = true

I guess I am not sure what you mean.

Yes that one. And if they only go in one direction then you need to set that to the opposite of what it is currently.

---

FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

I have it set as
//#define ENDSTOPPULLUPS (commented out)
const bool ENDSTOPS_INVERTING = false
What happens is the motors move around fine, they move in all directions and when they hit the endstops it is like nothing happened. This is the same behavior as if I was to leave it stock (like the first post where inverting was true).

If I change it to
#define ENDSTOPPULLUPS
const bool ENDSTOPS_INVERTING = false
They jump around and act really weird. They only move in one direction.

Quote

If I change it to
#define ENDSTOPPULLUPS
const bool ENDSTOPS_INVERTING = false
They jump around and act really weird. They only move in one direction.

Looks like your endstops are pretty unreliable, catching up electromagnetic noise.

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

How would you suggest fixing noise? I thought that is why the documentation has pull up resistors, but the Sanguinololu electronics exclude them. Can I put a cap between the two pins on the switch to get rid of the noise?

As a side note, can I just turn off endstops completely in the firmware? Obviously I would have to generate the gcode without homing, is there any other disadvantages?

Quote

How would you suggest fixing noise?

AFAIK, this noise was the reason why opto endstops were invented.

Quote

I thought that is why the documentation has pull up resistors

Nope. Pullups are required to produce a high signal while the switch is open. That said, ATmegas have pullups built in, to the one shown on the wiki page is redundant.

Quote

Can I put a cap between the two pins on the switch to get rid of the noise?

It's worth a try.

Quote

As a side note, can I just turn off endstops completely in the firmware?

Teacup firmware uses endstops for homing only (ignores them while printing) and has debouncing implemented (see ENDSTOP_STEPS in config.h), so you're pretty safe even with unreliable endstops.

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

Opto endstops are just as prone to noise as switches. It is the wiring that picks up the noise.

Built in pull-ups are weak and have a wide tolerance. External pull-ups are better for this application.

---

[www.hydraraptor.blogspot.com]