4028 fan on sht36 v1 toolboard not controllable
Hello, I read all the guide and all the other support threads on this topic, but I still cant figure it out.
Setup:
- Octopus 1.1
- SHT36 v1, connected via Canbus, not USB, heater and toolhead Fan works, so the toolhead should work
- Sanyo 12V 4028 fan connected with a step down converter (12V) to the 24V toolhead (dont want two extra wires running to the Octopus)
Problem:
The fan is always on 100%, also when Klipper has started up. It is not controllable from Mainsail.
Attached the wiring diagram. Not sure if the PC15 Pin on the toolboard is a standard GPIO I can use for PWM becuase of the other letter? But also tried PB1 and did not work as well.
I have a SuperPinda, so the PC15 and GND there is free to use.
Toolhead Config toolboard_fly36_GW.cfg (own toolhead config because of CAN):
[board_pins mellow-fly-sht-36]
mcu: toolboard
aliases:
[…]
# fans
** fan_part_cooling_pin=PC15,**
fan_toolhead_cooling_pin=PB11
printer.cfg
[…]
[include toolboard_fly36_GW.cfg] #thats my custom toolhead config, but only changed to CAN and the Fan header
[…]
[fan]
pin: !toolboard:PC15 #(also tried *!fan_part_cooling_pin* here)
cycle_time: 0.00004
I also tried the
[include RatOS/toolboard/4pin-partfan-25khz.cfg]
but did not understand how to change the PWM Pin, Klipper did not start up and showed errors.
6 Replies
Here also the complete configs, in case you want to see more. I PB1 and PC15 both as Pins.
Wiring
I can't see any errors in your wiring or configuration except the in / out in your drawing has 12v/24v reversed, but i assume that's just a mistake in the drawing.
If everything is as you wrote here wiring wise, it should work.
Which fan model do you have exactly?
Oh, since you're not using a fan port gpio you do not need the
! in front of the pin name in your config.
The reason you need that on the fan port pin is because it's a mosfetted ground connection, so the signal needs to be inverted.
I'm not sure why you wouldn't just use that instead of PC15 though.Hmm good to know i didnt make a big mistake 🙂 ill try to remove the ! Tomorrow.
I didnt use the fan port because the sanyo draws 1,3A which the small mosfet on the sht36 is not meant for and should be avoided to use, i read in the guide. I habe the 001 sanyo i think. The recommended one from ratrig.
Yeah from +/-. Not from PWM.
All our guides use the negative fan port for PWM control
+/- straight to power source.
It would actually be much worse on a regular GPIO if your assumption was correct. Those won't do much more than a few milliamps before the MCU dies.
True, sorry, was too late yesterday and it seems I mixed somethings up before that as well. Was thinking about doing the "the fan is too loud during startup" and for that the mosfet is too small. But I am not doing that now. But still thought I cant use the mosfet for the PWM. Mixed up.
Turns out: when I use the fan pin it works! Hallelujah! Maybe the GPIOs of the sht36 are not fast enough or something for the PWM? Just changed the Pin and now it works. Thanks again, again! You are a treasure. Will donate some money now. Hope you get paid enough by Ratrig. Not sure how that arrangement works.
Note to self: Never do something differently from the default, except you want to waste hours of your time.
Update: While trying to set up the SuperPinda I noticed that these Pins on the toolboard just dont work correctly. Pinda connected somewhere else does work, so my whole problem was just a Hardware-failure of some sorts.
Hmm, maybe it wasnt. PC15 on the SHT36 works with the Pinda. Not sure why. PB1 doesnt