bltouch clone , delta printer, z-min end-stop trigger
Hello, I have very strange issue.
Recently bought BLTouch sensor , reconfigured repetier 1.0.2 to enable servo and all the rest. It works fine but there is a catch. I'm not sure yet the issue but wanted to ask here first. Sometimes when doing G29 or G32 and the head start to lower down for probing the point (doing bilinear 3 point), the bltouch trigger, but head continue to move down and crash on bed. This happen ONLY sometimes
So at first it seems somehow either signal is not detected correctly from arduino - ie HW issue with my board or the software can not catch the signal at that time.
Is it possible that arduino miss the signal ? Is it possible a software issue preventing the HIGH peak (sometimes) to be detected and z-min endstop is not trigger ?
Here are more details.
The seller of the probe says the hall sensor output is directly connected to the output and the normal output state when bltouch pin is down (ready for probing) is LOW. I've connected an oscilloscope to the output pin of bltouch and monitor it constantly. When I push the pin up, it retracts, and I can see on scope the HIGH peak for some 5 ms. My z-min endstop is configured as 'Switch on GND normally closed'. And z-probe is set to TRIGGER_ON_HIGH.
For this I've slowed the probing speed to 2mm/s only to be able to catch the issue on time and prevent crashing the nozzle on bed (if that happens) using hard power off.
I'm currently testing it for HW issue - connected small voltage buffer/follower using J-FET so I can be sure the signal is good enough. But please elaborate on the software part if possible to miss endstop trigger.
Please help on this.
Recently bought BLTouch sensor , reconfigured repetier 1.0.2 to enable servo and all the rest. It works fine but there is a catch. I'm not sure yet the issue but wanted to ask here first. Sometimes when doing G29 or G32 and the head start to lower down for probing the point (doing bilinear 3 point), the bltouch trigger, but head continue to move down and crash on bed. This happen ONLY sometimes
So at first it seems somehow either signal is not detected correctly from arduino - ie HW issue with my board or the software can not catch the signal at that time.
Is it possible that arduino miss the signal ? Is it possible a software issue preventing the HIGH peak (sometimes) to be detected and z-min endstop is not trigger ?
Here are more details.
The seller of the probe says the hall sensor output is directly connected to the output and the normal output state when bltouch pin is down (ready for probing) is LOW. I've connected an oscilloscope to the output pin of bltouch and monitor it constantly. When I push the pin up, it retracts, and I can see on scope the HIGH peak for some 5 ms. My z-min endstop is configured as 'Switch on GND normally closed'. And z-probe is set to TRIGGER_ON_HIGH.
For this I've slowed the probing speed to 2mm/s only to be able to catch the issue on time and prevent crashing the nozzle on bed (if that happens) using hard power off.
I'm currently testing it for HW issue - connected small voltage buffer/follower using J-FET so I can be sure the signal is good enough. But please elaborate on the software part if possible to miss endstop trigger.
Please help on this.
Comments
#define ENDSTOP_PULLUP_Z_MIN false
Seems sane to me ? Maybe crosstalk ?
Correct me if I'm wrong but It seems to me somehow the z-probe signal 'high' is not detected from firmware. Is the z-probe pin state read continuously inside an interrupt routine ?
I've also tried to plug the z-probe at x-max, y-min, x-min - with and without hw min endstop defined at all.
Link to the video:
https://drive.google.com/file/d/1039fjlSfQeRa3DusEV_NoiHPqrRrBVVi/view?usp=sharing
Thanks