Basic Information: Printer Model: Elegoo Orange Storm Giga MCU / Printerboard: BTT Manta M8P, printhead: BTT EBB SB2209 CAN V1.0 Host / SBC: BTT CB1 klippy.log (2.4 MB) Edit: reworked the original thread for clarity. I’m using a Noctua 4 wire fan as the hotend fan connected to a BTT EBB SB…

I can guess you are talking not about “there is no data”, but about “I can’t see a number in the UI”. So, if you try to implement a simple macro like: [gcode_macro blink_led] gcode: M117 { printer["heater_fan heater_fan"].rpm } Can do the trick.

Thanks a lot for the reply. Apologies, but I’m not sure how the discussion you shared is of relevance for this discussion. Or am I not seeing something obvious in the shared discussion? I am using a 4 wire fan on a 4 wire header. There is no confusion on how to run the fan and everything seems to …

Oh, I’ve never thought about that actually. I assumed Klipper would automatically connect the tachometer data to the fan. I will try as soon as I can and update the thread.

It was not clear that it works fine except the output and where you expected the output. In my referenced link my printer showed the RPM next to the fan control slider in the Mainsail fan panel. However I do not know what you are trying to do.

You’re right, I’m very sorry. The description of my issue is indeed pretty bad. I will update and elaborate it later in the day, when I can take the time to actually describe it so others can understand.

I have tried to clarify what I’m having trouble with. I hope this makes it clearer.

This looks better now. Though the fan is working it looks like you have the wrong pins in use. Regarding to the official EBB SB2209 CAN config template this should be correct: [fan_generic 4W_FAN0] pin: EBBCan:gpio15 tachometer_pin: EBBCan:gpio12 #tachometer_ppr: 1 Did you use aliases for the pi…

I did make a test: [heater_fan heatbreak_cooling_fan] pin: ebb42:PA0 # FAN0 heater: extruder heater_temp: 70.0 fan_speed: 0.5 cycle_time: 0.003 tachometer_pin: PG15 # I do have hardware pull-up here tachometer_ppr: 2 tachometer_poll_interval: 0.0003 So, I remapped working tachopin from other fan,…

Probably it is the stm32 chip: MCU 'mcu1' config: ADC_MAX=4095 BUS_PINS_i2c1_PA9_PA10=PA9,PA10 BUS_PINS_i2c1_PB6_PB7=PB6,PB7 BUS_PINS_i2c1_PB8_PB9=PB8,PB9 BUS_PINS_i2c2_PA7_PA6=PA7,PA6 BUS_PINS_i2c2_PB10_PB11=PB10,PB11 BUS_PINS_i2c2_PB13_PB14=PB13,PB14 BUS_PINS_i2c3_PA7_PA6=PA7,PA6 BUS_PINS_i2c3_PB…

Fan tachometer not giving any value for `[heater_fan]`

General Discussion

LifeOfBrian October 10, 2025, 1:36pm 2

Maybe you can read here:

Hotend Fan RPM Monitoring? - General Discussion - Klipper

Topic		Replies	Views
Hotend Fan RPM Monitoring? General Discussion	10	5474	June 25, 2024
Klipper won't PWM a fan pin General Discussion	2	114	January 25, 2026
[Feature Request] Fan failure state based on tachometer reading Features	3	413	November 24, 2023
My fan is running always on General Discussion	4	1782	July 17, 2024
Duet 3+ Mini - pid cant be done (verify heater) General Discussion	26	735	October 29, 2023

Fan tachometer not giving any value for `[heater_fan]`

Related topics