Expansion board with 5v drivers



  • i have a duet 3d wifi + expansion board connected to some drivers that need 5v and NEMA 23 motors. i have already configurated correctly the firmware and i can see that the drivers are reciving correctly the signal, but the motors still dont move. I have double checked the information of the drivers and they necessarily need 5v to work.
    is there a way for making the 3.3v outputs from E2, E3, E4, E5 and E6 give 5v and use the drivers that i allready have?


  • administrators

    The more common reasons for external drivers not moving are:

    • Failure to increase the step pulse timing in the M569 command for the external driver channels.
    • Some external drivers have a disable function instead of an enable function, so the ENA+ and ENA- output wires need to be swapped. Check whether the external drivers are free at initial power up, but lock when you try to move them.

    If the differential outputs from the breakout board have insufficient output for your drivers (which is uncommon) then you can use 5V single ended drive instead. Instead of connecting the ENA+, STEP+ and DIR+ wires from your driver to the corresponding pins on the breakout board, connect those + wires from the driver to +5V on the Servo connector of the breakout board. Leave the + outputs on the breakout board not connected.



  • ok with the right configuration now i have my nema 23 with 5v drivers working well.
    now im trying to connect a bltouch z probe, i have conected the black and white conectors to the z probe pins and the other 3 cables to the 3 pin PWM7 on the breakout. when a i turn on the printer the probe deploy and retract as its usual but when i sen z axis home the probe dont deploy for start meshuring the bed, so i emergency stop the printer before an accident happens.
    this is my code on the endstops and probe configuration.

    ; Endstops
    M574 X1 Y2 S0 ; Set active high endstops

    ; Z-Probe
    M574 Z1 S2 ; Set endstops controlled by probe
    M558 P9 H5 F120 T6000 ; Set Z probe type to unmodulated and the dive height + speeds
    G31 P500 X0 Y0 Z2.5 ; Set Z probe trigger value, offset and trigger height
    M557 X15:11 Y15:195 S20 ; Define mesh grid



  • does the BLTouch deploy and retract when you issue the commands?

    This is the most thorough explanation I have found regarding setting it up on the Duet boards

    https://betrue3d.dk/bltouch-on-duet-wifi-configuratio-and-usage/


  • administrators

    @mrsyfo, have you set up the deployprobe.g and retractprobe.g files, and disabled heater 7 using a M307 command in order to make it available for the bltouch control input? https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Software_setup_Duet_2_WiFi_Ethernet



  • @dc42 wich is the correct code configuration for M307 to disable de heater on PWM7?

    ; Z-Probe
    M574 Z1 S2 ; Set endstops controlled by probe
    M307 H9 A-1 C-1 D-1 ; Disable heater on PWM channel for BLTouch
    M558 P9 H5 F120 T6000 ; Set Z probe type to bltouch and the dive height + speeds
    G31 P500 X0 Y0 Z2.5 ; Set Z probe trigger value, offset and trigger height
    M557 X15:11 Y15:195 S20 ; Define mesh grid



  • i think i have figured it out, the pwm pins on the breakboard of heater 7 are equivalent to PWM5 so im thinking that the correct code for me is the next one:

    Z-Probe
    M574 Z1 S2 ; Set endstops controlled by probe
    M307 H7 A-1 C-1 D-1 ; Disable heater on PWM channel for BLTouch
    M558 P9 H5 F120 T6000 ; Set Z probe type to bltouch and the dive height + speeds
    G31 P500 X0 Y0 Z2.5 ; Set Z probe trigger value, offset and trigger height
    M557 X15:11 Y15:195 S20 ; Define mesh grid

    am i right?


  • administrators

    @mrsyfo said in Expansion board with 5v drivers:

    i think i have figured it out, the pwm pins on the breakboard of heater 7 are equivalent to PWM5 so im thinking that the correct code for me is the next one:

    Z-Probe
    M574 Z1 S2 ; Set endstops controlled by probe
    M307 H7 A-1 C-1 D-1 ; Disable heater on PWM channel for BLTouch
    M558 P9 H5 F120 T6000 ; Set Z probe type to bltouch and the dive height + speeds
    G31 P500 X0 Y0 Z2.5 ; Set Z probe trigger value, offset and trigger height
    M557 X15:11 Y15:195 S20 ; Define mesh grid

    am i right?

    Yes you are right, and you need P7 in the M280 commands the deploy and retract the pin.


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