MobiFlight Community Support

My rudder pedals are done. I still have to tweak the forces a little bit and add ground roll vibration but otherwise they work very well. The issue I'm having though is that the PWM frequency is too low. I need to raise it to 20khz or so. Below are the changes that can make in the Arduino sketch to change the frequency of select pins. Can I just add that code to the Mobiflight mcc file? Is there an entry I can make to stay closer to the 16khz to 20khz range?

Code:

void setup() {
TCCR2B = TCCR2B & B11111000 | B00000001; // for PWM frequency of 31372.55 Hz
pinMode(9,OUTPUT);
TCCR2B = TCCR2B & B11111000 | B00000001; // for PWM frequency of 31372.55 Hz
pinMode(10,OUTPUT);
}

void loop() {
analogWrite(9,155);
analogWrite(10,155);
}

Holy Moly! I wouldn't even know where to begin adding this to the mcc file. There's another website where they mentioned adding it to the Arduino.h file. I need to go find that post again. Maybe there's a way to add it that way. I need 6 PWM pins with the higher frequency.
Some links for reference.

https://playground.arduino.cc/Code/PwmFrequency/

http://astro.neutral.org/arduino/arduino-pwm-pins-frequency.shtml?msclkid=5d7cc75ebe7011eca1e8f5029c8e4d64

https://www.etechnophiles.com/how-to-change-pwm-frequency-of-arduino-mega/

Hi

this would need to rework the Mobiflight Firmware itself.

In theory you can do this.... Simply load our source Code from Github and rework it for your own usage.

there is definitly no way to handle this in the MCC File.

I don't have a clue how to do that. If I could code, then I wouldn't need Mobiflight.

I installed Visual Studio Code and PlatformIO software. Then I downloaded the 2.1.1. source code. I opened each of the files in the folder. The only one that I found that resembled an Arduino sketch was the Mobiflight.ccp file. So I added the PWM lines in the void setup section of the file. so it now looks like this.

Code:

void setup()
{
  Serial.begin(115200);
  attachCommandCallbacks();
  cmdMessenger.printLfCr();
  ResetBoard();

  TCCR3B = TCCR3B & B11111000 | B00000010;  // for PWM frequency of 3921.16 Hz on pins 2, 3, and 5
  TCCR4B = TCCR4B & B11111000 | B00000010;  // for PWM frequency of 3921.16 Hz on pins 6, 7, and 8

// Time Gap between Inputs, do not read at the same loop
  lastButtonUpdate = millis() + 0;
  lastEncoderUpdate = millis();           // encoders will be updated every 1ms

#if MF_SERVO_SUPPORT == 1
  lastServoUpdate = millis() + 2;
#endif

#if MF_ANALOG_SUPPORT == 1
  lastAnalogAverage = millis() + 4;
  lastAnalogRead = millis() + 4;
#endif

#if MF_INPUT_SHIFTER_SUPPORT == 1
  lastInputShifterUpdate = millis() + 6;
#endif

#if MF_SERVO_SUPPORT == 1
  lastServoUpdate = millis() + 8;
#endif
}

I didn't add anything into the void loop section as that seem to be what the Mobiflight UI does.
The question now is, "How do I compile and upload this to the board I'm using for force feedback to test it?"
Please keep in mind I have absolutely no clue what I'm doing. This is a guessing game for me.
Hey look!!! The directions are right there on the github page...

WOOHOO!! It works. At 3921.16 Hz I can't hear anything. My wife can though The next higher frequency for the Mega board is 32Khz That may be too high for the motors to function correctly. I think the Uno can run at 16 Khz, but only on 1 channel. I'm going to research what boards will run the PWM at 16 Khz.
There is one (non?) issue I'm having. I used the 2.1.0 main file for the firmware change. Yet the UI states that version is 0.0.1. The other 2 boards are reading 2.1.1. All is working. Is this something to worry about.
Thanks.
John

If you compile the firmware locally on your PC the version will be always 0.0.1 unless you change it manually in one file.
I would test with 32kHz, your motor will not be damaged.
Regards
Ralf

I was going to try 32kHz, but the motor driver is only rated up to 25kHz.
I'll have an Uno in hand tomorrow. The D9 and D10 pins are capable of 15.6kHz which should work out great. I will need three of them when I decide to make my own yoke from scratch. Which will be pretty soon I think. I haven't fired up F360 for at least a month.

Hello Friend.
How did you upload modified .ccp on arduino board?

Cheers