BLTouch Homing in wrong direction

fcwilt

@chris said in BLTouch Homing in wrong direction:

@Phaedrux
here is an image bltouch pwm on heater 7 pwm and the switch wires on z probe in. was working fine before upgrading to v3.1.1.

I've not seen that little board before. Does it always use heater 7 for the Z probe?

Frederick

chris

yeah just makes heater 7 and heater 6 available from the ide / ribbon pin connector

https://www.duet3d.com/Expansion_Breakout

Phaedrux

In that case I would suggest removing the breakout board entirely. You can connect directly to the needed pins on the expansion port. Using the breakout board is likely changing the name of the pin being used for the M950 definition, but I'll have to check what that is. In the meantime, just connect the BLtouch directly to the expansion pins as shown here.

chris

@Phaedrux just for the heater pwm pins

fcwilt

@chris said in BLTouch Homing in wrong direction:

yeah just makes heater 7 and heater 6 available from the ide / ribbon pin connector

https://www.duet3d.com/Expansion_Breakout

And you verified the connector you are using is the heater 7 connection?

I wasn't able to determine which connector did what.

Frederick

chris

used multimeter to prove continuity between the pins on idc ribbon cable and heater pwm pins

Phaedrux

I think it may behave like the Duex pwm pin and just needs to be inverted in RRF3.

So if you still want to use the expansion breakout board, try inverting the servo pin command by adding an exclamation point like this

; Z-Probe
M950 S0 C"!exp.heater7"                         ; create servo pin 0 for BLTouch

chris

@Phaedrux didn't have dupont connector hence why was using breakout board only on old firmware used H7 not exp.heater7 which is what 3.1.1 set it as M950 S0 C"exp.heater7"

Phaedrux

If the exclamation point to invert doesn't work, might need to change the pin name

M950 S0 C"duex.pwm5" also might need to be inverted, but I'm not sure. I've never seen anyone use the breakout board for the BLtouch, so until I get some confirmation we'll just have to experiment.

chris

seems inverting pin may have worked deploy macros now working

fcwilt

@chris said in BLTouch Homing in wrong direction:

used multimeter to prove continuity between the pins on idc ribbon cable and heater pwm pins

OK then I think at this point you may just want to try the various other names.

exp.heater3, exp.8, !duex.e2heat, !duex.pwm1
exp.heater4, exp.13, !duex.e3heat, !duex.pwm2
exp.heater5, exp.18, !duex.e4heat, !duex.pwm3
exp.heater6, exp.23, !duex.e5heat, !duex.pwm4
exp.heater7, exp.31, !duex.e6heat, !duex.pwm5

I have the Duex5 board and this is my command M950 S0 C"duex.pwm5"

Frederick

Phaedrux

@chris said in BLTouch Homing in wrong direction:

seems inverting pin may have worked deploy macros now working

That's good.

chris

any advice on how to reduce how close nozzle is to bed currently

G31 P25 X46.5 Y0 Z3.6

do I change the 3.6mm height?

Phaedrux

Follow these steps to measure the trigger height

https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe#Section_Calibrate_the_Z_probe_trigger_height

Then afterwards when testing your first layer use the baby stepping function to adjust. Then take the amount of baby stepping used and modify the G31 Z value.

A larger G31 Z value moves the nozzle and bed closer together. If it's too close, make G31 Z smaller.

chris

so reduce the 3.6 to like 3.4?

Phaedrux

bedlevel_nozzle_0.4_200x200-0.3-0.8.stl

I'd suggest printing a test pattern like this and adjusting the baby stepping to find out exactly how much to change it.

But yeah, 0.2 sounds like a reasonable amount to start with.