search

bigtreetech / EBB

435 stars 100 forks source link

Document the use of 3 pin PWM + Tach fans with EBB #48

Open sammcj opened 1 year ago

sammcj commented 1 year ago

It would be great if the use of 3 (or even 4) pin PWM + Tachometer fans could be documented.

For example - is it "safe" to use the PA0 (FAN0/1 header) for +/- and a single pin from the I2C header, say PB4 for the sense/pulse yellow wire? Are there any risks?

Personally I've noticed when wiring a 3 pin fan up like this the fan never stops spinning at idle, there must be some sort of current / loop occurring when adding the PB4 to the sense/pulse connection.

ebb36-3-pin-pwm-tach-fan

For context - It's generally a good idea to use a fan with a tach for your hotend cooling to avoid potential disasters should it fail or become blocked during a print - for example: https://ellis3dp.com/Print-Tuning-Guide/articles/useful_macros/hotend_fan_monitoring.html

longshanks1977 commented 5 months ago

Did you ever get an answer as to whether this setup is safe?

sammcj commented 5 months ago

Nope, BTT has never responded to me :(