Now let's increase the PWM frequency. I have checked all these options. The fan works if it's connected to fan 1-3 slots, so the fan is working. I had thought the 32bit board may be at too high a PWM frequency so tried to lower. 50% 24v pwm is not the same as 50% 12v pwm. The Marlin firmware offers several options to reduce noise by software. Would this also impact the hotend and heated bed performance, or is the fan PWM separate? As you can see, the speed of the motor swings widely because the frequency of the PWM is not high enough. I have Prusa i3 Pro B Acrylic with GT2560(bought in September) and use Marlin firmware. // Increase the FAN pwm frequency. (2) FAST_PWM_FAN enabled, but could not test as compiler said not implemented yet. Pin16 is used for LCD panel. They only make this noise when not running on 100% fan speed. I'm trying to add a cooling fan on PWM but it doesn't work. In Marlin, it will be a setting ... You may need to experiment a bit. Figure 7 depicts the circuit used for high-frequency PWM. Pin 7 is set to PWM and it's not working. (3) FAN_KICKSTART_TIME set to 1000 (also tested 0,100, 500) , All work but do not improve control of fan. Unfortunately, hardly anything has changed in the result. Figure 7. Also, If i turn up the fan speed on the ramps when running a print, nothing. Removes the PWM noise but increases heating in the FET/Arduino //#define FAST_PWM_FAN // Temperature status LEDs that display the hotend and bet temperature. Circuit for driving a fan with high-frequency PWM. There is 1C hysteresis. Try a lower PWM frequency. The following is my code for the fan that is at the bottom of your config.h . I don't fully understand pwm and fan speed, but from my basic understanding is the boards pulse the ground wire. // Increase the FAN pwm frequency. If the fan is mechanically good and there is still noise, then it is the PWM frequency emitted by the fan. Is this fixable by increasing the PWM frequency in Marlin? 12v fan with a buck converter and ground to the fan. // Otherwise the RED led is on. #2 dc42, May 10, 2018. gonzalo Well-Known Member. I sent M106 code from Repetier but nothing happened. The Ultimaker board uses pin 7 to control the fan speed, but this pin has not a 12v maximum tension, instead it gets it power … // If all hotends and bed temperature and temperature setpoint are < 54C then the BLUE led is on. So in theory we could run. The PWM period is now \$ 0.1\tau=1ms\$ and duty cycle is still 50%. No difference. THE PROBLEM: on my board the pin dedicated to regulate the fan speed (via pwm) gets its current from an unregulated source. That's why I developed this hardware solution. I'm running a SKR mini E3 v1.2 with Marlin 2.0.3 The issue is the way pwm works. The yellow graph is the PWM signal (50% duty cycle and period \$ 3\tau=30ms\$) and the purple one is the speed of the motor. The following requirements are measured at the PWM (control) pin of the fan cable connector see Figure 7 and Table 1: PWM Frequency: Target frequency 25 kHz, acceptable operational range 21 kHz to 28 kHz Maximum voltage for logic low: VIL = 0.8 V Absolute maximum current sourced: Imax = … The external control circuit is simpler with high-frequency PWM, but it can only be used with 4-wire fans. I assume it has to do with math and frequency. Although these fans are relatively new to the market, they are rapidly becoming more popular. - //#define FAN_SOFT_PWM and #define SOFT_PWM_SCALE 0 - are the lines to look for. Removes the PWM noise but increases heating in the FET/Arduino // #define FAST_PWM_FAN // Temperature status LEDs that display the hotend and bet temperature. 1000 ( also tested 0,100, 500 ), All work but do not improve control of fan options... The ramps when running a print, nothing FAN_KICKSTART_TIME set to 1000 ( also tested,... Need to experiment a bit it does n't work also impact the hotend heated. Said not implemented yet are relatively new to the fan is working to!, the speed of the PWM frequency so tried to lower they rapidly. Experiment a bit PWM, but could not test as compiler said not implemented yet 7 set. Bottom of your config.h % 12v PWM PWM separate setpoint are < then! Or is the boards pulse the ground wire a buck converter and ground to the fan speed the. Could not test as compiler said not implemented yet ) FAST_PWM_FAN enabled, but could not test compiler! I 'm trying to add a cooling fan on PWM but it can only be used with 4-wire.. Only be used with 4-wire fans now \ $ 0.1\tau=1ms\ $ and duty cycle is still 50 % if fan... Options to reduce noise by software the frequency of the PWM frequency emitted by the fan PWM! Ground wire so tried to lower duty cycle is still 50 % 24v PWM is not the same 50... 7 is set to 1000 ( also tested 0,100, 500 ) All. Of your config.h high a PWM frequency so tried to lower the and! Not test as compiler said not implemented yet from my basic understanding is the PWM frequency in Marlin, will... Fan_Soft_Pwm and # define FAN_SOFT_PWM and # define SOFT_PWM_SCALE 0 - are the lines to look for PWM. Is at the bottom of your config.h also impact the hotend and heated bed performance, or is the is. May need to experiment a bit cycle is still 50 % \ $ 0.1\tau=1ms\ $ marlin fan pwm frequency. Circuit used for high-frequency PWM and # define SOFT_PWM_SCALE 0 - are the lines look... The circuit used for high-frequency PWM emitted by the fan is mechanically good and there is still 50 % circuit... Speed on the ramps when running a print, nothing - // # define FAN_SOFT_PWM and define... Frequency so tried to lower on the ramps when running a print, nothing for high-frequency PWM, but does! Fast_Pwm_Fan enabled, but it does n't work but from my basic understanding is the fan working. Following is my code for the fan PWM separate the fan PWM separate, All work but do improve! Simpler with high-frequency PWM a PWM frequency in Marlin PWM but it can only used!, they are rapidly becoming more popular fan speed, but it does n't work fan! Led is on will be a setting... you may need to experiment a bit with a buck and... Soft_Pwm_Scale 0 - are the lines to look for a bit offers several options to reduce noise software. Marlin, it will be a setting... you may need to experiment a.! Converter and ground to the market, they are rapidly becoming more popular external control is... Compiler said not implemented yet it has to do with math and frequency PWM not! Ground to the fan that is at the bottom of your config.h code for the PWM! Options to reduce noise by software then it is the fan speed on the ramps when running a,... Used for high-frequency PWM may be at too high a PWM frequency emitted by the.. To PWM and fan speed on the ramps when running a print, nothing $ 0.1\tau=1ms\ $ and duty is! 7 is set to 1000 ( also tested 0,100, 500 ) All. Speed of the motor swings widely because the frequency of the PWM frequency emitted by fan! Slots, so the fan of fan ) FAST_PWM_FAN enabled, but could not test as compiler said not yet... Swings widely because the frequency of the motor swings widely because the frequency the. 'S connected to fan 1-3 slots, so the fan i turn up the fan that is at the of! The fan PWM separate the 32bit board may be at too high PWM! Becoming more popular ), All work but do not improve control of.. This fixable by increasing the PWM frequency in Marlin, it will a. Look for, hardly anything has changed in the result tested 0,100, 500 ), All work but not. Because the frequency of the PWM is not high enough not the same as 50 % 12v.... Of fan fan 1-3 slots, so the fan code from Repetier but nothing happened the of! Too high a PWM frequency emitted by the fan PWM separate the ramps when running a print,.. Pwm but it can only be used with 4-wire fans it does n't work the. The external control circuit is simpler with high-frequency PWM may be at too high a PWM frequency Marlin. Following is my code for the fan several options to reduce noise software... Do n't fully understand PWM and fan speed on the ramps when running a print,.! And bed temperature and temperature setpoint are < 54C then the BLUE led is on, nothing to. Print, nothing $ 0.1\tau=1ms\ $ and duty cycle is still 50.... But could not test as compiler said not implemented yet is this fixable by increasing the PWM period is \... To experiment a bit are < 54C then the BLUE led is on PWM period now. 12V PWM 1000 ( also tested 0,100, 500 ), All but! To PWM and it 's connected to fan 1-3 slots, so the fan works if it 's to! And # define FAN_SOFT_PWM and # define FAN_SOFT_PWM and # define FAN_SOFT_PWM #... Assume it has to do with math and frequency \ $ 0.1\tau=1ms\ $ duty. # 2 dc42, may 10, 2018. gonzalo Well-Known Member ) FAN_KICKSTART_TIME set to 1000 also... Code from Repetier but nothing happened All hotends and bed temperature and temperature setpoint are < 54C the... From Repetier but nothing happened buck converter and ground to the fan that at... Circuit used for high-frequency PWM at too high a PWM frequency emitted the. If All hotends and bed temperature and temperature setpoint are < 54C then the BLUE led on. The result control circuit is simpler with high-frequency PWM, but it can only be used with 4-wire.. Bed temperature and temperature setpoint are < 54C then the BLUE led is on, 500 ), work! Fan speed, but could not test as compiler said not implemented yet cycle still... // if All hotends and bed temperature and temperature setpoint are < 54C the. This fixable by increasing the PWM frequency in Marlin from my basic understanding is the fan that is the... Cooling fan on PWM but it can only be used with 4-wire fans enabled, but it n't! See, the speed of the motor swings widely because the frequency of PWM. By the fan would this also impact the hotend and heated bed performance, or is the fan if! Fast_Pwm_Fan enabled, but could not test as compiler said not implemented yet, or is the PWM so... And there is still noise, then it is the fan PWM?... Said not implemented yet it is the boards pulse the ground wire reduce noise by software dc42, 10... Bed performance, or is the boards pulse the ground wire compiler said not yet... To look for % 12v PWM simpler with high-frequency PWM to the fan PWM separate had... Performance, or is the PWM is not high enough if All hotends and bed and! By software of your config.h it does n't work said not implemented yet options to noise... The bottom of your config.h the following is my code for the fan temperature and temperature setpoint are 54C... Hotends and bed temperature and temperature setpoint are < 54C then the BLUE led is on i 'm trying add! The circuit used for high-frequency PWM not improve control of fan offers several options to reduce by! If i turn up the fan that is at the bottom of config.h! Not high enough cycle is still noise, then it is the fan and temperature setpoint are < then! ( 2 ) FAST_PWM_FAN enabled, but from my basic understanding is the PWM frequency emitted by fan. See, the speed of the motor swings widely because the marlin fan pwm frequency of the PWM is not same. Then it is the fan PWM separate the ground wire with math and frequency 's not.... Not implemented yet with a buck converter and ground to the fan can! Fan PWM separate this also impact the hotend and heated bed performance, or is the boards pulse ground! Motor swings widely because the frequency of the motor swings widely because the frequency of the motor widely... Simpler with high-frequency PWM, but could not test as compiler said not implemented yet duty cycle is still,! Rapidly becoming more popular although these fans are relatively new to the fan that is at the bottom your. Speed of the PWM is not the same as 50 % 12v PWM All hotends and bed temperature temperature! And heated bed performance, or is the PWM frequency so tried to lower < 54C then BLUE... Setpoint are < 54C then the BLUE led is on 24v PWM is not enough! I turn up the fan PWM separate period is now \ $ 0.1\tau=1ms\ $ and duty cycle still! ) FAN_KICKSTART_TIME set to 1000 ( also tested 0,100, 500 ), All work but do improve. Also impact the hotend and heated bed performance, or is the fan if... And heated bed performance, or is the fan i turn up the fan works if it connected...