inverting Z-probe pin



  • Hello!!!

    I'm using a precision piezo for Z probe on my Duet 2 Wifi. On RRF version 3 i've managed to invert the signal of the piezo using the "I" parameter (I1). since RRF 3.01-RC2 i haven't be able to invert the signal using "I1" as per documentation, instead i need to invert the pin using a "!" before the pin name, but isn't working for me.

    here's how i'm doing it

    M558 P1 C"!zprobe.in+zprobe.mod" H5 R1 F420 T6000
    

    is something missing here?

    thanks 😊



  • Don't you have a M950 command where you can invert the pin?



  • @bearer said in inverting Z-probe pin:

    M950 com

    Wow, that's new to me 😌 😌 😌
    i have some M950 for endstops, but not for the zprobe.in



  • @bearer can't find any examples of how can i do that... 😞



  • Maybe those are already defined for the Duet2; not too familiar with Duet 2 + RRF and just sort of assumed it would be a M950 thing if M558 didn't accept the!

    Maybe someone will have another idea.


  • administrators

    @celulari said in inverting Z-probe pin:

    Hello!!!

    I'm using a precision piezo for Z probe on my Duet 2 Wifi. On RRF version 3 i've managed to invert the signal of the piezo using the "I" parameter (I1). since RRF 3.01-RC2 i haven't be able to invert the signal using "I1" as per documentation, instead i need to invert the pin using a "!" before the pin name, but isn't working for me.

    here's how i'm doing it

    M558 P1 C"!zprobe.in+zprobe.mod" H5 R1 F420 T6000
    

    is something missing here?

    You are running the piezo in analog mode (P1 in the M558 command). Is that intentional? It might be that pin level inversion isn't working in analog mode.



  • @dc42 said in inverting Z-probe pin:

    You are running the piezo in analog mode (P1 in the M558 command). Is that intentional? It might be that pin level inversion isn't working in analog mode.

    Yes, that's intentional, because my piezo is under constat preasure and when i switch to digital mode is triggered constantly. i'been using it without troubles on RRF 3.0 using the "I1" parameter but i have no luck inverting the signal on newer versions.


  • administrators

    I'll enable inversion of analog pins in 3.01-RC5.



  • @dc42 said in inverting Z-probe pin:

    I'll enable inversion of analog pins in 3.01-RC5.

    THANK YOU!!!



  • @dc42 said in inverting Z-probe pin:

    I'll enable inversion of analog pins in 3.01-RC5.

    Thanks. I need that as well.



  • Just tried 3.01-RC5 and my analog piezo probe is no longer working. OK in 3.01-RC4.

    In RC4 it sits at 525 when untriggered but in RC5 it sits at 497 and does not respond to pressure on the probe.

    Defined like this

    M558 P1 C"^!zprobe.in" R0.5 H3 F360 T9000 A5 S0.03       ; P1 = Analogue mode 
    G31 X0 Y0 Z-0.1 P530                                     ; X, Y, Z offsets, P530 = trigger threshold
    

    Do I need to change anything for RC5?



  • Works OK in Digital Mode in 3.01RC5

    M558 P8 C"^!zprobe.in" R0.5 H3 F240 T9000 A5 S0.03      ; P8 = Digital mode (unfiltered)
    G31 X0 Y0 Z-0.1 P100                                    ; X, Y, Z offsets, P100 = debounce interval
    
    

    Something has changed between RC4 and RC5. I only have one probe which should default to probe 0 so nothing to do with the new K parameter.



  • @tekkydave i'm using mine in analog mode and is working as intended... Funny thing, never managed to work in digital mode


  • Moderator

    @tekkydave The implication from the couple of posts before your first one is that analogue pins can't be inverted, so the "!" in your initial config wasn't doing anything. Try without it, as the inversion works as of RC5.

    Ian



  • @celulari said in inverting Z-probe pin:

    @tekkydave i'm using mine in analog mode and is working as intended... Funny thing, never managed to work in digital mode

    Are you using the PP V2.85 board? If so remember you need to move the connector to the next set of pins in from the edge to pick up the 'D' output. Apologies if you already knew that but I keep forgetting myself 🙂

    Mine works great in analog mode except in 3.01RC5. I prefer analog as you don't need to fiddle with the crappy pots on the pcb. I had a V2 pcb and the pots fell apart after about 20 adjustments. The only downside is the 1/3 slowdown but @dc42 said this in a previous post:

    " it's likely that in a future version of RRF3 I will remove the automatic slowdown and replace it with 2 configurable feedrates in the M558 command: a fast feedrate for initial probing, and a slower feedrate for the second and subsequent probes, for those types of sensor that benefit from slow probing."



  • This post is deleted!


  • @droftarts said in inverting Z-probe pin:

    @tekkydave The implication from the couple of posts before your first one is that analogue pins can't be inverted, so the "!" in your initial config wasn't doing anything. Try without it, as the inversion works as of RC5.

    Ian

    That fixed it - many thanks 🙂



  • @tekkydave said in inverting Z-probe pin:

    Are you using the PP V2.85 board? If so remember you need to move the connector to the next set of pins in from the edge to pick up the 'D' output. Apologies if you already knew that but I keep forgetting myself 🙂

    Mine works great in analog mode except in 3.01RC5. I prefer analog as you don't need to fiddle with the crappy pots on the pcb. I had a V2 pcb and the pots fell apart after about 20 adjustments. The only downside is the 1/3 slowdown but @dc42 said this in a previous post:

    " it's likely that in a future version of RRF3 I will remove the automatic slowdown and replace it with 2 configurable feedrates in the M558 command: a fast feedrate for initial probing, and a slower feedrate for the second and subsequent probes, for those types of sensor that benefit from slow probing."

    I didn't knew about that! thanks, i will try, but now is working fine with RC5 as i can now invert the analog pin


  • Moderator

    @tekkydave said in inverting Z-probe pin:

    That fixed it - many thanks

    Funny, because I didn't think it would! It's probably the pull up resistor ^ that you 'needed' to stop it being permanently triggered.

    Ian



  • @droftarts said in inverting Z-probe pin:

    @tekkydave said in inverting Z-probe pin:

    That fixed it - many thanks

    Funny, because I didn't think it would! It's probably the pull up resistor ^ that you 'needed' to stop it being permanently triggered.

    Ian

    The ! must have been in there from an earlier release but had become redundant. Until RC5 came along and actually inverted the input, stopping it from working.
    The pullup (^) is only needed in digital mode. It probably doesn't do anything in analog mode; why would you pull up an analog input?


  • Moderator

    @tekkydave said in inverting Z-probe pin:

    why would you pull up an analog input?

    Good point, I'm a bit tired and not thinking so well!

    Ian



  • I've just removed the ^ too and as expected - makes no difference.

    Correct setup for analog is

    M558 P1 C"zprobe.in" R0.5 H3 F360 T9000 A5 S0.03         ; P1 = Analogue mode
    G31 X0 Y0 Z-0.1 P530                                     ; X, Y, Z offsets, P530 = trigger threshold
    

    and for digital:

    M558 P8 C"^!zprobe.in" R0.5 H3 F240 T9000 A5 S0.03      ; P8 = Digital mode (unfiltered)
    G31 X0 Y0 Z-0.1 P100                                    ; X, Y, Z offsets, P100 = debounce interval
    

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