Hardware_pwm Octopus1.0

General Discussion
1

Basic Information:

Printer Model: Ender3
MCU / Printerboard: BTT Octopus v1.0 STM32F446
Host OrangePi3lts

Hi everyone.
Where are the hardware_pwm_pins on this board (yep, 1.0, not pro/1.1)?
SPI PB5 busy (max31865). Someone wrote that SPI pin (MOSI) have this mode. Where else there Hardpwm?

Am I the only one with 1.0?=))

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  1. Hardware PWM is not related to SPI
  2. Why do you need it?
  3. If you do not have a compelling reason to use it, then don’t. It has disadvantages and no real life benefit
1 Like
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1.Thanks. It turns out that I was deceived
2. Connected roborock fan.)
3. “no real life benefit”. PWM works 15-100%.=(

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P.S. And what are the disadvantages?

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This is expected behavior. Most (all) fans have a “lower limit” before they start spinning.

  1. The hardware PWM and its duty cycles depend on the MCU hardware and its implementation. As such, what you like to set in your configuration may only be very coarsely represented due to the MCU not supporting this specific duty cycle
  2. The very high PWM freqs are not needed for fans
  3. Only dedicated pins on the MCU even support hardware PWM and this differs from MCU to MCU and you would need to research which pins on your MCU do support this function
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Understood. Thanks! I’ll find the datasheet on the mcu later. But for the sake of interest.

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I think I found it.
STM32F446 hardware pwm pins:
PH2 PC6 PC7 PC8 PC9 PF7 PB14 PB15 PA6 PF8 PA7 PF9
This is not accurate.
But I won’t connect via “hard” anymore. I’ll leave it as it is.

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