CHANGING THE ARDUINO(ATMEGA328) PWM FREQUENCY

CHANGING ARDUINO PWM FREQUENCY

In some projects like boost and buck converters we may need to change the default frequency of Arduino PWM pins according to our need in order to control the charging time of inductor. in Arduino UNO pins D5 and D6 have PWM frequency of 62500 HZ, pins D3, D11, D9 and D10 has the default PWM frequency of 31250 HZ .

To change the PWM frequency following code can be written in setup function to set PWM frequency

Divide the base frequency of pins by the factor you want to decrease the frequency for each pin some examples are shown below

The divisors available on pins 5, 6, 9 and 10 are: 1, 8, 64, 256, and 1024.

The divisors available on pins 3 and 11 are: 1, 8, 32, 64,128, 256, and 1024.

for D3 and D11

TCCR2B = TCCR2B & B11111000 | B00000001; // for PWM frequency of 31372.55 Hz

TCCR2B = TCCR2B & B11111000 | B00000010; // for PWM frequency of 3921.16 Hz

TCCR2B = TCCR2B & B11111000 | B00000011; // for PWM frequency of 980.39 Hz

TCCR2B = TCCR2B & B11111000 | B00000100; // for PWM frequency of 490.20 Hz (The DEFAULT)

TCCR2B = TCCR2B & B11111000 | B00000101; // for PWM frequency of 245.10 Hz

TCCR2B = TCCR2B & B11111000 | B00000110; // for PWM frequency of 122.55 Hz

TCCR2B = TCCR2B & B11111000 | B00000111; // for PWM frequency of 30.64 Hz

for D5 and D6

TCCR0B = TCCR0B & B11111000 | B00000001; // for PWM frequency of 62500.00 Hz

TCCR0B = TCCR0B & B11111000 | B00000010; // for PWM frequency of 7812.50 Hz

TCCR0B = TCCR0B & B11111000 | B00000011; // for PWM frequency of 976.56 Hz (The DEFAULT)

TCCR0B = TCCR0B & B11111000 | B00000100; // for PWM frequency of 244.14 Hz

TCCR0B = TCCR0B & B11111000 | B00000101; // for PWM frequency of 61.04 Hz

for D9 and D10

TCCR1B = TCCR1B & B11111000 | B00000001; // set timer 1 divisor to 1 for PWM frequency of 31372.55 Hz

TCCR1B = TCCR1B & B11111000 | B00000010; // for PWM frequency of 3921.16 Hz

TCCR1B = TCCR1B & B11111000 | B00000011; // for PWM frequency of 490.20 Hz (The DEFAULT)

TCCR1B = TCCR1B & B11111000 | B00000100; // for PWM frequency of 122.55 Hz

TCCR1B = TCCR1B & B11111000 | B00000101; // for PWM frequency of 30.64 Hz

Sample application code

void setup() {

TCCR2B = TCCR2B & B11111000 | B00000001; // PWM frequency of 31372 Hz on pin 3
pinMode(3,OUTPUT);

}

void loop() {
analogWrite(3,155);

}

the change in timer related function on 3, 5, 6, 11will affect some functions like millis() and delay()

and change in pin 9 or 10 will cause servo related function to work incorrectly.

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Some of the photos of my projects that managed to survive long enough on my gallery. fig : RLDA data acquisition project (2023 February) fig : DAQ preparation for RLDA (2023 February) fig : DAQ controller board (2023 February) fig : DAQ system testing on bump rig (2022 November) fig: 8 channel strain gauge DAQ system with 10 uV precision and 1000 HZ sampling frequency (2022 November) fig : 8 channel strain gauge DAQ board Ki-CAD PCB (2022 October) fig: PCB wire tresses (2022 October) fig : Four channel 24 bit ADC board interfaced with teensy4.1 for high speed data acquisition fig : four channel instrumentational amplifier (2023 January) fig : Ki-CAD PCB design four channel instrumentation amplifier (2023 October) fig : Instrumented bike chassis (2022 October) fig : Half bridge strain gauge application on steel rod (2022 October) fig : STM 32 pneumatic rig control board (2022 September) fig : Strain gauge data verification setup (2022 September) fig : Instrumentation amplifier ADA4254

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