Ok in commands.cpp you have
case 106: // M106 Fan On
if(com->hasI()) {
if(com->I != 0)
Printer::flag2 |= PRINTER_FLAG2_IGNORE_M106_COMMAND;
else
Printer::flag2 &= PRINTER_FLAG2_IGNORE_M106_COMMAND;
}
if(!(Printer::flag2 & PRINTER_FLAG2_IGNORE_M106_COMMAND)) {
if(com->hasP() && com->P == 1)
setFan2Speed(com->hasS() ? com->S : 255);
else
setFanSpeed(com->hasS() ? com->S : 255);
}
break;
So no limit. This calls setFanSpeed
void Commands::setFanSpeed(int speed, bool immediately) {
#if FAN_PIN >- 1 && FEATURE_FAN_CONTROL
if(Printer::fanSpeed == speed)
return;
speed = constrain(speed, 0, 255);
Printer::setMenuMode(MENU_MODE_FAN_RUNNING, speed != 0);
Printer::fanSpeed = speed;
if(PrintLine::linesCount == 0 || immediately) {
if(Printer::mode == PRINTER_MODE_FFF) {
for(fast8_t i = 0; i < PRINTLINE_CACHE_SIZE; i++)
PrintLine::lines[i].secondSpeed = speed; // fill all printline buffers with new fan speed value
}
Printer::setFanSpeedDirectly(speed);
}
Com::printFLN(Com::tFanspeed, speed); // send only new values to break update loops!
#endif
}
At the beginning you see constrain to 0-255.
This calls setFanSpeedDirectly:void Printer::setFanSpeedDirectly(uint8_t speed) { uint8_t trimmedSpeed = TRIM_FAN_PWM(speed);#if FAN_PIN > -1 && FEATURE_FAN_CONTROL if(pwm_pos[PWM_FAN1] == trimmedSpeed) return;#if FAN_KICKSTART_TIME if(fanKickstart == 0 && speed > pwm_pos[PWM_FAN1] && speed < 85) { if(pwm_pos[PWM_FAN1]) fanKickstart = FAN_KICKSTART_TIME / 100; else fanKickstart = FAN_KICKSTART_TIME / 25; }#endif pwm_pos[PWM_FAN1] = trimmedSpeed;#endif
}Here TRIM_FAN_PWM could be the problem#if !defined(MAX_FAN_PWM) || MAX_FAN_PWM == 255#define TRIM_FAN_PWM(x) x#undef MAX_FAN_PWM#define MAX_FAN_PWM 255#else#define TRIM_FAN_PWM(x) static_cast<uint8_t>(static_cast<unsigned int>(x) * MAX_FAN_PWM / 255)
#endif
As you see if you defined MAX_FAN_PWM 100 then 100 then what you describe would happen, but you would need to set this explicitly. But maybe you did.
