i have the same probe,5V pinda probe.

i testet it on a raspberry pi with the 3,3V output and it worked.

is it save to use the z probe input for it?

the problem after updating to 1.21 was that the 2 z screws didnt move synchron,its looked like the motor on the z connect was half as fast like the motor on e1

a downgrade to 1.20 worked and the z axis works perfect
thank you

I got a problem with my printer after updating to 1.21.
i have dual z and after the update its look like one motor is slower then the other.
its the same if i home or do G1 Z10 S2.
i cant even downgrad back to 1.20
could someone help me?

here my config.g

; Configuration file for Duet WiFi (firmware version 1.17)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Fri Jun 16 2017 18:06:21 GMT+0200 (Mitteleuropäische Sommerzeit)
M80
;M307 H2 A-1 C-1 D-1

; General preferences
M111 S0                         ; Debugging off
G21                             ; Work in millimetres
G90                             ; Send absolute coordinates...
M83                             ; ...but relative extruder moves
M555 P2                         ; Set firmware compatibility to look like Marlin
M208 X0 Y0 Z0 S1                    ; Set axis minima
M208 X250 Y250 Z250 S0                     ; Set axis maxima

; Endstops
M574 X1 Y1 Z0 S0 ; Define active low and unused microswitches

M558 P5 X0 Y0 Z1 H2 F1000 T6000             ; Set Z probe type to unmodulated, the axes for which it is used and the probe + travel speeds
G31 X0.0 Y0.0 Z0.9 P600                    ; Set Z probe trigger value, offset and trigger height
; Drives
M569 P0 S1                         ; Drive 0 goes forwards
M569 P1 S1                         ; Drive 1 goes forwards
M569 P2 S0                         ; Drive 2 goes forwards
M569 P3 S1                         ; Drive 3 goes forwards
M569 P4 S0                        ; Drive 4 goes forwards

; Motor remapping for dual Z
M584 X0 Y1 Z2:4
M671 X-15:260 Y127:127 S5

M350 X64 Y64 Z64:64 E16 I1                 ; Configure microstepping with interpolation
M92 X320 Y320 Z1600:1600 E418.5                ; Set steps per mm
M566 X600 Y600 Z16:16 E120                 ; Set maximum instantaneous speed changes (mm/min)
M203 X7200 Y7200 Z100:100 E1200                 ; Set maximum speeds (mm/min)
M201 X3200 Y3200 Z50:50 E200                 ; Set accelerations (mm/s^2)
M906 X1000 Y1000 Z800:800 E900 I30             ; Set motor currents (mA) and motor idle factor in per cent
M84 S30                         ; Set idle timeout

; Heaters
M143 S270                         ; Set maximum heater temperature to 270C
M301 H0 S1.00 P10 I0.1 D200 T0.4 W180 B30         ; Use PID on bed heater (may require further tuning)
M305 P0 R4700 T100000 B3950                ; Bed thermistor (P0) is 100K @ room temp
M305 P1 R4700 T100000 B4388                 ; Set thermistor + ADC parameters for heater 0

; Tools
M563 P0 D0 H1                         ; Define tool 0
G10 P0 X0 Y0 Z0                     ; Set tool 0 axis offsets
G10 P0 R0 S0                         ; Set initial tool 0 active and standby temperatures to 0C

; Network
M550 PPrusa-I3                         ; Set machine name
M552 S1                         ; Enable network
M587 S"FRITZ!Box Fon WLAN 7390" P"xxxxxxx"; Configure access point and IP addresses. You can delete this line once connected
M586 P0 S1                         ; Enable HTTP
M586 P1 S0                         ; Disable FTP
M586 P2 S0                         ; Disable Telnet

; Fans
;M106 P1 S1.00 T60 H1 F100

;M106 P0 S0.3 I0 F500 H-1                 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F500 H1 T70                 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
;M106 P2 S1 I0 F500 H1                  ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on
T0

First its M98 Pbed.g
and the "zagzag" underline is your operating system who made this,its the spell correction

i´m totally new to the duet boards,can i use the TMC2660 on the duex5 and duex2 to run additional x,y,z motors or only E motors?