Duet2 Wifi & Always On (+24V) & exp.heater(?) (gnd)
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@alankilian Nope, no joy.
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The only thing else I can think of is to check your wiring and make sure you are connected to the signal you think you are.
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@alankilian Did double check. Not the issue...
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@Reefwarrior said in Duet2 Wifi & Always On (+24V) & exp.heater(?) (gnd):
Now I would like to use the PWM signal from one of the expansion headers (eg. exp.heater3 or exp.heater6).
is this a 4 wire fan or a mosfet module? not sure how much current the pwm signal would need but the duet is offering around 2mA
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@bearer It's a normal 2 wire fan - one red; one black wire. 24V, 0.04A
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Can't run that off the expansion port pins without a mosfet module or something else to drive the fan. (0.04A is (much) more than 0.002A)
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Alternatively, will it work if I just add a resistor between the fan and the ground terminal? I have another fan connected on one of the PWM pins (Fan02); and it is much more quiet than this fan on the 'always on'. I have swapped out fans, and it is definitely not the fan itself.
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@bearer Thanx didn't know. Any other suggestions then?
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The only other buffered pin is the z probe modulate thing, but iirc the 74125 is only good for +-20mA so nowhere near enough.
You need some sort of external components like a mosfet or anything else that can drive the fan from the 2mA available from the expansion port.
(edit: Or possibly look into how much current you need to to drive the PWM signal for a 4-wire fan, the whole point of the 4-wire fan is to control the fan speed with a small signal, but how small idk)
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you can run the fan off the second heater port.
edit nevermind its in use i see.
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@bearer Thanx!
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it says signal range 3.3v so if that is true it will work; if not for the real possibility that your order is shipped with a different mosfet than the one I've got here I'd test it and report back.
(edit: it says dual mosfet, but it can only control one fan btw - it just mean there are two mosfet in parallel to control large loads)
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@Reefwarrior said in Duet2 Wifi & Always On (+24V) & exp.heater(?) (gnd):
Can I connect the + of the fan to the + of the always on, and the - to the exp.heater6?
No, that will probably damage the processor. You would be applying 24V through the fan to a pin that is tolerant of about 3.8V max. You need to use an external mosfet driven from the exp.heater6 to switch the fan.
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Thank you for the help! Working like a charm!
