BlTouch 3.1 Flashing and Troubleshooting

Veti

see

https://duet3d.dozuki.com/Wiki/BLTouch_Troubleshooting

and note this
https://forum.duet3d.com/topic/10654/bl-touch-and-the-duex-5/64

H2B

Thanks for the tip, but I've already tried all of that before posting

I am truly stumped at what's causing this..

PaulHew

If you were to power off the printer, wait 5 secs, power back on, does the probe deploy and retract, or does it go into this error state?

H2B

@PaulHew it's perpetually stuck in the error state. Soft resets, hard power resets, you name it, nothing seems to wake it up.

H2B

Is there any way I could write a macro to hold an S10 signal to the probe for at least 500ms? I could then perform the 5V logic reset procedure from the antclabs manual. I have a feeling my other Marlin setup has the eeprom locked into 5V mode instead of open drain operation..

PaulHew

Have you tried a different port just incase there is something up with H3?

P.

dc42

@H2B said in BlTouch 3.1 Flashing and Troubleshooting:

M558 P5 H5 F500 T4000 X0 Y0 Z1 ; Set Z probe type/mode 5. H=Dive Height. F=Speed the bed moves

You have not configured the BLTouch correctly. The probe type should be 9, and the XYZ parameters should be removed.
You don't need the M574 Z1 S2 command, a Z probe (such as BLTouch) is completely different from an endstop in RRF
If you still have problems with this, please post your deployprobe.g and retractprobe.g files.

To reset your BLTouch, send: M280 P3 S160. If that doesn't work, check your wiring. if it does, you may wish to include this at the end of config.g:

M280 P3 S160 ; send the reset command to BLTouch
G4 S250 ; give it time to work
M42 P3 S0 ; set BLTouch command signal low

H2B

@dc42 said in BlTouch 3.1 Flashing and Troubleshooting:

M42 P3 S0

So thanks for all the help so far. I've cleaned up the config as @dc42 has suggested, and wasn't getting anything.

Until I tried measuring the voltage drop across the probe control supply rails. As soon as my multimeter touches the +5V and GND pins, the probe comes to life. Seems to be an issue with the wiring somewhere that I still can't figure out. Most likely crimping issues. Going to try that and let you guys know if its working now. Cheers!!

PaulHew

With my previous reply, I had many variations of my reply including crimping and cable.
I have crimped onto the insulator before and wondered why things were not working!
But some people are not as silly as me, thank goodness!

Hope you get it fixed.

Veti

the supplied extension cable is notoriously bad

H2B

So @Veti I'm using an extension cable I made myself, soldered and crimped on all ends (except the small servo connector into the probe).

@dc42 just checked all the wiring leads/extensions. Reading 0.1Ohm everywhere, great continuity. Thoroughly tested the resistance across: the extension cable alone, extension to probe connector, extension to probe PCB, and finally Duex to Probe PCBs. I get 0.1Ohm to 0.2 Ohm throughout, so I know there's no wiring issue.

Here's the fun fact: as soon as I'm measuring voltage from the GND on the Duex PWM pin to the probe 5V rail for control, the Duex LED for E2 lights up and the probe boots up. Seems like I'm having some weird voltage drop somewhere, and I can't trace it. As soon as I disconnect the multimeter leads, the Duex LED goes dimmer again.

The Duex is wired with Vin straight from my PSU in parallel with the Duet (nothing else is running across it right now, I know the correct wiring is from Vin on Duet to the Duex), and I can't seem to crack this one.. Any ideas?

Veti

@H2B said in BlTouch 3.1 Flashing and Troubleshooting:

The Duex is wired with Vin straight from my PSU in parallel with the Duet (nothing else is running across it right now, I know the correct wiring is from Vin on Duet to the Duex), and I can't seem to crack this one.. Any ideas?

there is a very big warning not to do that in bold here
https://duet3d.dozuki.com/Wiki/Duex2_and_Duex5_Features

Connect VIN and GND terminals of the Duex 5 to the corresponding terminals of the Duet 2. Do not run separate ground wires from each terminal block back to the power supply unless the power supply is very close (less than 100mm) to the Duet 2 and Duex. Instead, run a very short and thick ground wire directly from the negative (-) terminal of the VIN terminal block on the Duex board to the negative VIN terminal of the Duet. Also connect the negative wire from your power supply to the negative VIN terminal of the Duet. You can run separate +VIN wires from the Duet 2 and Duex back to the positive terminal of the power supply if you wish.

H2B

@Veti I am aware of that, thanks for the reminder though. No steppers are on the board so the likelihood of any large transient current is almost zero. But I went ahead and wired up properly with crimps on all terminals and a common 16awg ground between the 2 boards. Safety first!

@dc42 tried a brand new BLTouch with the connector that comes with it. Same issue. Works if I measure voltage across the probe control 5v and GND again. Same happens when I connect it to PWM2. No chance of a floating ground this time either. What a great way to spend a Sunday afternoon! Thanks for all the help!

Veti

@H2B said in BlTouch 3.1 Flashing and Troubleshooting:

No steppers are on the board so the likelihood of any large transient current is almost zero.

can you disconnect the duex then and see if works on the duet normally.
just to confirm that the problem is not with the duex or its wiring

H2B

Same issue again. Touched it with the multimeter leads, it works. Remove them, it stops. And every time I touch it with the leads to measure voltages, the LEDs on the Duet get brighter (so more current draw). Never seen anything loaded by a voltmeter before..

H2B

Same thing is still happening with nothing connected to the Duet2 except the BLTouch and Vin. All jumpers are in the right place, no steppers or anything really is connected. I am stupified...