I am trying to tune the PIDs of my V6 Hotends but I am a little confused. First I run the autotune command via Repetier. Then I tansfer the new PID values via the M301 P.. I.. D.. command via repetier to the printer. If I check the parameter in the lcd-menue I find exact the transfered values there. But if a set the same values in configuration.h eg #define DEFAULT_Kp 5.0 #define DEFAULT_Ki 0.50 #define DEFAULT_Kd 50.0 save and load the firmware I always find following values in the lcd-menue: PID-P 29.20 PID-I 4.73 PID-C 45.33 independent of what I set in configuration .h I double checked if I edit the correct configuration.h and saved before compiling and uploading. I think I found the reason: Malrin RepRap Wiki: EEPROM If you have established known working PID constants, acceleration, and max-velocity settings for your own machine, you can set them, then store them in the EEPROM. On each boot-up, Marlin will automatically load these values from EEPROM, independent of what your compiled Configuration.h says.
Read default values from configuration.h and load to the EEPROM with M502 save again with M500. https://github.com/MarlinFirmware/Marlin/wiki/EEPROM
Hello Greg, thank you for the tip. At the moment i switched off EEPROM usage (#define EEPROM_SETTINGS) for my test phase and set the parameters in the firmware.