Duet2 Eth/Duex5 2tacho readnig

[matej1006]

Hello it's possible to read two tacho meter on DUET2 Etherne+Duex5
one is from noctua fan other is from water cooling system
LINK fot cooling tachometer
and if it's possible to show this two value on DWC or not?

Part of code:

; Water colling NOCTUA FAN'S #########################################################################################
M950 F1 C"!duex.fan7+exp.pb6" Q25000 							; fan 0 is a 4-wire PWM fan so invert it, use high PWM frequency, tacho connected to PB6 on expansion connector
M106 P1 H5 I1 T20:25 L125 S1
; Water colling PUMP #################################################################################################
M950 F2 C"!Fan0+exp.pb5" Q25000 ; fan 2 is a 4-wire PWM fan so invert it, use high PWM frequency
M106 P2 H5 I1 T20:25 L255                                       ; set fan 2 value. Thermostatic control is turned on

thanks for help

[droftarts]

@matej1006 See 'Connecting a 4-wire fan' tab here https://docs.duet3d.com/User_manual/Connecting_hardware/Fans_connecting#connecting-fans-to-duet-fan-pins

Tacho wire (yellow or green): optionally, connect the tacho wire of a 4-wire fan to the cathode of a small signal diode (1N4148 should be OK) and connect the anode of the diode to any available digital input pin, to provide a reading of the fan RPM. For example, on Duet 2 WiFi/Ethenet connect it to pin PB6, and on Duet 2 Maestro use one of the four expansion pins.

See the Duet 2 pinout for available digital input pins: https://docs.duet3d.com/Duet3D_hardware/Duet_2_family/Duet_2_WiFi_Ethernet_Hardware_Overview#inputoutput
You should be able to use pretty much any pin with has 'Yes' or 'Input only' in the 'Input/Output' column.

M950 F2 C"!Fan0+exp.pb5" Q25000

There is no 'exp.pb5' pin.

Ian

[matej1006]

@droftarts

Can i then connect pump to any other input on duex5 and change it to tacho input to gp 1-4 or not ?

[droftarts]

@matej1006 I think that should work. See the DueX list of pin names and capabilities here https://docs.duet3d.com/en/Duet3D_hardware/Duet_2_family/DueX2_and_DueX5#inputoutput

Ian

[matej1006]

@droftarts

can you help me why i get 1500RPM and i got this code

M308 S5 P"e0temp" Y"thermistor" T10000 B10000 C7.06e-8 A"Water temp." ; define E0 temperature sensor sensor 5 as thermistor on pin e0temp water temp.
M950 F1 C"!duex.fan7+exp.pb6" Q25000                                 ; fan 0 is a 4-wire PWM fan so invert it, use high PWM frequency, tacho connected to PB6 on expansion connector
M106 P1 H5 T23:25                                           ; set fan 0 value. Thermostatic control is turned on

e0temp as i read is 22.5 then fan must be off and not turn at 1500 rpm

do i need any resistor between 5v and PWM signal or something like that?

Please help thanks

[droftarts]

@matej1006 Did you add the diode? I believe it is required on Duet 2:

connect the tacho wire of a 4-wire fan to the cathode of a small signal diode (1N4148 should be OK) and connect the anode of the diode to any available digital input pin

Ian

[matej1006]

@matej1006 yes i added diode

[droftarts]

@matej1006 The example on the fans page shows exp.pb6 with pullup resistor ^ enabled. Not sure if that is needed:

: 4-wire PWM fan and tacho
M950 F2 C"!fan2+^pb6" ; Fan 2 uses the Fan2 output, but we are using a PWM fan so the output needs to be inverted, also we are using PB6 as a tacho input with pullup resistor enabled

Can you manually control the fan correctly? Send M106 P1 H-1 to turn off thermostatic control, then M106 P1 S0 to turn the fan off and M106 P1 S255 to turn it on. If it is inverted, remove ! from M950 command.

Ian

[matej1006]

@droftarts @droftarts i run at full speed 255 and it's show 1500 rpm or i run at 125 and is same 1500 rpm

[droftarts]

@matej1006 Difficult to say what is going wrong. It's possible connecting it to the DueX is the issue (maybe latency?), in which case connect the tacho wire direct to a pin on the Duet. It's also possible that the fan tacho doesn't comply with the specification for tacho wires that RRF uses.

Ian

[matej1006]

@droftarts @dc42

I have connected my flow sensor like that and show always 0

1 GND commom for all voltages
2 5V external power supply
3 signal connected duex.gp4

; Water colling PUMP #############################################################################################################
M950 F2 C"Fan0+^duex.gp4" Q25000                     ; fan 2 is a 4-wire PWM fan so invert it, use high PWM frequency