BLTouch + Expansion Breakout Board



  • @dc42 Thank you, I will post in some minutes the picture of the wiring here... thanks a lot for your attention!



  • Ok... it has been more a couple of days than minutes... it seemed simple , but to me it's a hard task ☹

    I am lost in this connections...please help 😓

    My doubts (newbie ones):
    RED BOARD has ENABLE and DIRECTION only... but the other board has it with + and -
    RED BOARD has 9V ... where should I get that from?
    RED BOARD has 5V and @dc42 told me to use 3.3V ... I see that the pins on the Duet Wifi has 3.3v nomination, but when thay get to the Expansion Breakout they are all 5V.
    Motor + and - ....should I connecto to Step + and - ?

    alt text

    Thanks!


  • administrators

    1. I said:

    You could connect that board directly to the Duet expansion connector, or to the CONN_LCD connector;

    I did not say you could connect it to one of the outputs from the external stepper driver breakout board.

    1. I don't know why it is telling you to connect Vm to 9V, I guess it means 9V is the minimum voltage you can apply to Vm for the stepper driver chip to work. The capacitor in your photo is rated at 35V. So you can connect that pin to VIN.

    Important: make sure you have a good connection between the ground pins on that board and Duet ground. If the ground wires break then you will end up feeding VIN into the Duet output pins that you use to drive STEP, DIR and EN.



  • Thank you,

    "I did not say you could connect it to one of the outputs from the external stepper driver breakout board."... Sorry, I assumed that... so, it seems the breakout board in my case is useles, since I can wire both external motor driver and the BL Touch direclty to DUET Wifi, correct?

    Or... in the case of the External Motor, should or could I buy another unit that is compatible with the Duet External Brekout ?

    The fact is I need another Axis to be added to control the Independent X carriage.
    I have the duet wifi and the breakout from duet, what else should I buy to make it work (ready solutions, I wont make anything)

    Would the Duet Expansion Breakout connect seamlessly with a TB6600 external driver?

    thanks, you are being very helpful!



  • Is this wiring correct in case I decide to use the small red board I have?

    alt text

    Please note the questions on the previeous post.

    thanks a lot.


  • administrators

    That looks correct.

    For the TB6600, looking at the information I found on google it should work fine
    https://www.dfrobot.com/wiki/index.php/TB6600_Stepper_Motor_Driver_SKU:_DRI0043

    Using the Pul(Step), Dir and En. If you are connecting it to the expansion breakout board then you should connect the + and - signals to the board.



  • Thank you @T3P3Tony

    Another question that came up here when configuring the firmware was:

    Since the DRV8825 has miliamper settings done physicaly, should I let the U axis with no value inside the motor current section on the firmware? or if I set it on the firmware it will override the physical settings?

    I followed this guide (https://duet3d.dozuki.com/Wiki/ConfiguringMultipleIndependentXcarriagesCartesian) until I reaced the HOMEALL.g configuration. I didn't want to mess with tools until I get the motor of the U carriage running well. But nothing hapened, I can't home nor move the U axis.

    When I try to home or move U it returns (I don't have an endstop wired for this axis yet):

    M120
    G91
    G1 U10 F6000
    M121
    Error: G0/G1: insufficient axes homed
    Error: Bad command: ''' Home U at the high end of the axis'''
    Error: G0/G1: insufficient axes homed

    Error: G0/G1: insufficient axes homed
    Error: Pop(): stack underflow!

    thanks,


  • administrators

    @3dealo For external drivers the current setting in firmware has no effect.

    I would try setting the U axis up as its own axis first and texting it before you use it as part of an IDEX setup. Also you may find it easier to use the external drivers to drive your extruder or Z axis and keep the other motion axis on the on board drivers. You can use M584 to swap waht drivers do what to experiment with which is best:
    https://duet3d.dozuki.com/Wiki/Gcode#Section_M584_Set_drive_mapping



  • @t3p3tony Thanks.

    I tryied do map the X as a driver 5 just to see if the motor would move, but nothing hapened, I entered this at the top of the code:

    M584 X5 Y1 Z2 U0 E4

    I dont know what I'm doing wrong to test the external motor


  • administrators

    If it's a DRV8825 then those drivers are slow so you need to increase the step pulse timing to 2.5us in the M569 command.



  • @dc42

    Hi again @dc42 ,
    Now I got it working with some guidance it was driver 11 not 5, but there's a glitch... the motor connected is getting hotter and hotter without any use... any idea? Thanks


  • administrators

    @3dealo said in BLTouch + Expansion Breakout Board:

    @dc42

    Hi again @dc42 ,
    Now I got it working with some guidance it was driver 11 not 5, but there's a glitch... the motor connected is getting hotter and hotter without any use... any idea? Thanks

    Turn down the motor current using the potentiometer on the driver.



  • @dc42 I will try, but the current is not high, at least not for the setup we used to have with the MKSs, I don't know if with this setup the current must be lower than before. Let's try it! Thanks


  • administrators

    The other possibility is that the driver is faulty or there is a short. Does the motor move normally when commanded?



  • @dc42 The motor runs correctly, the thing is that in stand by it's getting hot. The cables and the driver are not getting hot. And I think the motor only gets hot after the first move I make with it.



  • @dc42 Just tested , more than an hour with the board ON and the motor is cold, the problem comes with the 1st signal that activates the motor.


  • administrators

    @3dealo said in BLTouch + Expansion Breakout Board:

    @dc42 Just tested , more than an hour with the board ON and the motor is cold, the problem comes with the 1st signal that activates the motor.

    That's normal. Motor drivers are not enabled until they are first used. For the internal drivers on the Duet, the motor current is reduced to the idle setting (default 30%) when the printer has been idle for 30 seconds. But the Diet can't reduce the current of external drivers. You can use M18 or M84 to disable external drivers at the end of a print.

    Plug-in stepper driver modules invariable have totally inadequate heatsinking (the PCBs are far too small), so unless you use them at very low currents, you should use a fan to cool them.



  • Hi there ,
    Back to BL Touch, please help...
    I believe I tried every tutorial, forum post and variation (maybe that's the problem... I probabbly did a mess)

    And here is how my Bl Touch is behaving on each setup:

    SETUP 1 (connected to the expansion pins on Duet wifi using heater 3)

    1 - It does the self test
    2 - Stays with the probe retracted and the red light on
    3 - I can command it with M401 to lower the pin
    4 - If I do a M402 or a G30 to start a probing pass it goes looping on deplying and retracting thr pin with the red light on.

    SETUP 2 (connected to the expansion breakout board on heater 7)

    1 - It does the self test
    2 - Stays with the probe deployed and the very low blue light on
    3 - I can command it with M280 P7 S90 to retract the pin (red light turns on)
    4 - I can command it with M280 P7 S10 to deploy the pin
    5 - If I do a M402 or a G30 to start a probing pass it goes looping on deplying and retracting thr pin with the red light on.

    I already tried other unit , same results.

    PS: a part from coding mess up, the only phisical thing that happened was that the 1st time (and some others) I connected the bl touch to star testing I did not used the resistor to low from 5v to 3.3v... hope that didn't dammaged the Duet.

    thanks



  • Does your deployprobe.g file contain : M280 P7 S10 ?



  • @scachi yes it does... Is that correct?
    Thanks


 

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