bissen21/Marlin_Firmware
1
0
Fork 0
Code Issues Pull Requests Projects Releases 4 Wiki Activity

Allows user to set (almost) any PWM frequency (#12638)

Browse Source
This commit is contained in:
Reece Kibble
2019-03-08 16:15:42 +08:00
committed by Scott Lahteine
parent afbec5ff7e
commit dbead66988
80 changed files with 2314 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
Marlin/Configuration_adv.h
View File

@ -241,6 +241,33 @@
//#define FAN_MIN_PWM 50
//#define FAN_MAX_PWM 128
/**
* FAST PWM FAN Settings
*
* Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
* Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
* frequency as close as possible to the desired frequency.
*
* FAST_PWM_FAN_FREQUENCY [undefined by default]
* Set this to your desired frequency.
* If left undefined this defaults to F = F_CPU/(2*255*1)
* ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
* These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
* NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
*
* USE_OCR2A_AS_TOP [undefined by default]
* Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
* 16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
* 20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
* A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
* PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
* USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
*/
#if ENABLED(FAST_PWM_FAN)
//#define FAST_PWM_FAN_FREQUENCY 31400
//#define USE_OCR2A_AS_TOP
#endif
// @section extruder
/**