I have recently bought a L293D shield and 2 BO motors. Whenever I connect the motors to the shield it makes a beeping noise. I searched online and found that I need to change PWM frequency but I know nothing about it and anyone please tell me about the PWM frequency and how to change it.
I have used almost every sketch found online but condition remains same. I am using 9V battery as External power supply and it is absolutely new. Please help me.
Acting as a conduit for Google: Arduino Change PWM Frequency shows me:
https://playground.arduino.cc/Code/PwmFrequency
Which has the following example function:
/** * Divides a given PWM pin frequency by a divisor. * * The resulting frequency is equal to the base frequency divided by * the given divisor: * - Base frequencies: * o The base frequency for pins 3, 9, 10, and 11 is 31250 Hz. * o The base frequency for pins 5 and 6 is 62500 Hz. * - Divisors: * o The divisors available on pins 5, 6, 9 and 10 are: 1, 8, 64, * 256, and 1024. * o The divisors available on pins 3 and 11 are: 1, 8, 32, 64, * 128, 256, and 1024. * * PWM frequencies are tied together in pairs of pins. If one in a * pair is changed, the other is also changed to match: * - Pins 5 and 6 are paired on timer0 * - Pins 9 and 10 are paired on timer1 * - Pins 3 and 11 are paired on timer2 * * Note that this function will have side effects on anything else * that uses timers: * - Changes on pins 3, 5, 6, or 11 may cause the delay() and * millis() functions to stop working. Other timing-related * functions may also be affected. * - Changes on pins 9 or 10 will cause the Servo library to function * incorrectly. * * Thanks to macegr of the Arduino forums for his documentation of the * PWM frequency divisors. His post can be viewed at: * http://forum.arduino.cc/index.php?topic=16612#msg121031 */ void setPwmFrequency(int pin, int divisor) { byte mode; if(pin == 5 || pin == 6 || pin == 9 || pin == 10) { switch(divisor) { case 1: mode = 0x01; break; case 8: mode = 0x02; break; case 64: mode = 0x03; break; case 256: mode = 0x04; break; case 1024: mode = 0x05; break; default: return; } if(pin == 5 || pin == 6) { TCCR0B = TCCR0B & 0b11111000 | mode; } else { TCCR1B = TCCR1B & 0b11111000 | mode; } } else if(pin == 3 || pin == 11) { switch(divisor) { case 1: mode = 0x01; break; case 8: mode = 0x02; break; case 32: mode = 0x03; break; case 64: mode = 0x04; break; case 128: mode = 0x05; break; case 256: mode = 0x06; break; case 1024: mode = 0x07; break; default: return; } TCCR2B = TCCR2B & 0b11111000 | mode; } } And numerous results from this SE community also:
https://www.google.com/search?q=arduino+change+PWM+frequency+site:arduino.stackexchange.com
Which note methods for calculating/setting specific frequencies and pitfalls and side-effects of making such changes.
