Duet2 Eth/Duex5 2tacho readnig

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