Question about M106



  • Hi,

    The online documentation for M106 says that the speed can be set using 0 to 255 or 0.0 to 1.0.

    This does not appear to be true for the firmware I am currently using when controlling a fan connected to a Duex5 v0.7 board.

    Only 0.00 to 1.00 seems to work.

    Is this correct?

    0_1542900366545_Firmware Info.jpg


  • administrators

    0 to 255 should work as well. Values of 1.0 or lower are assumed to be in the range 0 to 1, values above 1 are assumed to be in the range 0 to 255.



  • @dc42 said in Question about M106:

    0 to 255 should work as well. Values of 1.0 or lower are assumed to be in the range 0 to 1, values above 1 are assumed to be in the range 0 to 255.

    I just tested it again with LEDs as it is a bit easier to view the result

    0 by itself does turn the LEDs off BUT 1 to 255 all seem to be the same - full on.

    0.00 to 1.00 does yield varying light levels.

    The slider in DWC confirms this.

    Is the number in the 2nd decimal place (x.x#) intended to change the speed/level by 1%?

    I cannot be sure that I am seeing such a small change in the light level.

    Thanks.

    Frederick


  • administrators

    The resolution depends on the PWM frequency you have set. It's usually well below 1%.

    What commands are you sending to adjust the PWM?



  • @dc42 said in Question about M106:

    The resolution depends on the PWM frequency you have set. It's usually well below 1%.

    What commands are you sending to adjust the PWM?

    According to the docs the FAN outputs on the Duex5 v0.7 do not have adjustable frequency.

    To test M106 I have tried:

    M106 P6 S0.0 - LEDs are off - DWC slider = 0%
    M106 P6 S0.5 - LEDS are medium - DWC slider is 50%
    M106 P6 S1.0 - LEDS are max - DWC slider is 100%

    M106 P6 0 - LEDs are off - DWC slider is 0%
    M106 P6 2 - LEDS are max - DWC slider is 100%
    M106 P6 255 - LEDS are max - DWC slider is 100%

    Frederick


  • administrators

    OK, you are using fans on the DueX board. I'll re-test those, because I only tested direct-connect fans in my recent tests.


  • administrators

    I found there is a problem using values in the range 2-255 if you have other parameters in the M106 command. For example, M101 P6 S128 sets the fan to half PWM; but M106 P6 S128 F100 sets it to full PWM. I will fix this in the next 2.02RC.



  • @dc42 said in Question about M106:

    I found there is a problem using values in the range 2-255 if you have other parameters in the M106 command. For example, M101 P6 S128 sets the fan to half PWM; but M106 P6 S128 F100 sets it to full PWM. I will fix this in the next 2.02RC.

    Thanks for the feedback.

    But what you found does not match what I found, at least with it comes to a Duex5 v0.7.

    No extra parameters had to be present for the S1 through S254 values to cause the setting (according to the DWC slider) to be 100%.

    Frederick


  • administrators

    @fcwilt said in Question about M106:

    No extra parameters had to be present for the S1 through S254 values to cause the setting (according to the DWC slider) to be 100%.

    I was unable to reproduce that, it worked perfectly for me provided that the only parameters to the M106 command were P and S.



  • @dc42 said in Question about M106:

    @fcwilt said in Question about M106:

    No extra parameters had to be present for the S1 through S254 values to cause the setting (according to the DWC slider) to be 100%.

    I was unable to reproduce that, it worked perfectly for me provided that the only parameters to the M106 command were P and S.

    I will check it again.

    Frederick



  • @dc42 said in Question about M106:

    @fcwilt said in Question about M106:

    No extra parameters had to be present for the S1 through S254 values to cause the setting (according to the DWC slider) to be 100%.

    I was unable to reproduce that, it worked perfectly for me provided that the only parameters to the M106 command were P and S.

    Well I went back and tested it and it now works - values from 1 to 255 have the expected effect.

    Under any conditions does the firmware "remember" that extra parameters were used at one point and apply them for subsequent commands that have only P and S?

    Frederick


  • administrators

    No, it doesn't.



  • @dc42 said in Question about M106:

    No, it doesn't.

    Then I will just have to keep an eye on the problem and see if it reappears and under what circumstances.

    Thanks.

    Frederick


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