Coolstep configuration



  • Hi, I want to configure Coolstep on my HEVO, but I do not know what to include in the M915 gcode, the wiki is not too helpful


  • administrators

    The value you enter in the M914 T parameter goes into the coolstep configuration register of the TMC2660. Read the section of the TMC2660 datasheet about coolStep for more information.



  • @dc42 I read it a lot of times but I still don't know how to configure it


  • administrators

    From section 5.1 of the TMC2660 datasheet:

    Before tuning coolStep, first tune the stallGuard2 threshold level SGT, which affects the range of the load measurement value SG. coolStep uses SG to operate the motor near the optimum load angle of +90°.

    SGT is set by the M915 S parameter. You can use the min/max SG values reported by M122 to help find an appropriate value.

    After that, set SEMIN according to whether you want the minimum current to be 1/2 or 1/4 of the configured current, and SEUP and SEDN depending on how fast you want coolStep to react to changes in load.



  • Yeah, I get that, but I dont get how to enter it as a 16bit integer into the T part


  • administrators

    @patakopecek said in Coolstep configuration:

    Yeah, I get that, but I dont get how to enter it as a 16bit integer into the T part

    Use the table in section 6.7 of the datasheet to work out the bit pattern, and express bits 0-15 as a 16-bit integer.


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