BLTouch 3.0 and 3.1 Info/ Possible fix for M112 failed probing

[DeathDonky]

Really new to this but I did come across a "fix" that may be worth mentioning... I am using an Ender 3v2 with this flipping AMAZING firmware. Thank you 1: for including your SOURCE codes because that allowed me, a nobody in this world, to learn. I really appreciate that. It allowed me to not only learn but 2: customize the ender with your great features to my parts. Love it. Please keep going. anyway...

With the ender 3v2 I'm using a BLTouch v3.1. it is a genuine BLTouch. Upon installing many other firmware and finally settling with this one I came across an issue where about only 30% of my pre-print probs would complete. for example, I used a 3x3, 5x5, and currently a 7x7(custom) probe grid before each print. (I'm an accuracy nut...) In either grid setting... I might get through 3 points, might get through 8, might get to the very last one but only about 30% of the time would it complete. This happened on stock to custom firmware and I kept chasing the issue. When it would fail id get the "M112 Kill command restart printer required" Now Jyers has that help page which shows how to setup octoprint to ignore these failed probes and just carry on with the print anyway. It would get the error and start blinking like normal and then just move over to its warmup position and print. My issue with this is I didn't have the peace of mind that my mesh was proper. yes the print would carry on and I no longer had to power cycle but that wasn't the fix I needed.

Come to find out in the config adv file there is a setting for "#define BLTOUCH_SET_5V_MODE". ONLY IF ITS A BLTOUCH V3.0 OR 3.1 DOES THIS PERTAIN TO.

I am happy to report i now have a 100% probe success rate now and have probed the bed every bit of 200+ times. Remember before id get maybe a 30% success. Now all my probes are passing and i have octoprint set back up to not ignore errors.

Idk if this is useful... I hope it is as i know i want the only one chasing this...

On a side note i have tested both with and without the HS probing enabled. Both cases 100% success rate.

[MrDragon420]

I also have probeing issues... will have to try this

[t3chguy]

@DeathDonky chances are the capacitance on your multimeter/probes is high enough that due to how short the signal edge is the multimeter will under-measure, these sorts of signals need to be measured on an oscilloscope.

[DeathDonky]

In either case the voltage received to the bltouch was a constant 5v... across black and white wire. it didn’t change regardless of the configuration.adv setting and the multimeter was capable of that at least because it was constant.

[t3chguy]

Yes, that voltage comes from the 5V regulator.
The Marlin config is how to configure the operation of the BLTouch in software, this changes what the BLTouch does with its output pin in its own hardware.
in 5V mode it changes how the output pin works. in 5V mode it sends 5V/GND signals, without that mode it is an open drain output so it can be used with a lower voltage system like 3v3 of the ARM chip as the ARM chip pulls the GPIO up to 3.3v via an internal resistor and the BLTouch grounds it or leaves it floating depending on the state. No 5V -> ARM which can (and will eventually) cause damage. The current is low enough that the damage will not be immediate or quick but nearly certain.

[gothcha]

@t3chguy Thank you for the support :-)

[DeathDonky]

That really sucks. Looks like octoprint will be going away from the ender for the time being then..