[SOLVED] How to change pwmWrite freq?

I need to use more than 500hz for generating sound but I can`t change PWM freq. How to do that?

melodic wrote:I need to use more than 500hz for generating sound but I can`t change PWM freq. How to do that?

I have the same problem. Then I use setOverflow then PWM stop to work.

const int analogInPin = 11;
const int pwmOutPin = PA1;

int sensorValue = 0;
int outputValue = 0;
HardwareTimer pwmtimer(2);
void setup() {
pinMode(analogInPin, INPUT_ANALOG);
Serial.begin(115200);
pinMode(pwmOutPin, PWM);
pwmtimer.pause();
pwmtimer.setPrescaleFactor(1);
pwmtimer.setCount(0);
//pwmtimer.setOverflow(4000);
pwmtimer.setCompare(TIMER_CH2, 1000);
pwmtimer.refresh();
pwmtimer.resume();
pinMode(pwmOutPin, PWM);
}

void loop() {
sensorValue = analogRead(analogInPin);
outputValue = map(sensorValue, 0, 4095, 0, 65535);
pwmWrite(pwmOutPin, outputValue);

Serial.print("sensor = " );
Serial.print(sensorValue);
Serial.print("\t output = ");
Serial.println(outputValue);
}

I think the slow frequency of PWM is caused by the higher bitrate (16bit vs 8bit):
http://leaflabs.com/docs/lang/api/analogwrite.html
So the maximum is about 1.1KHZ.
I didn’t researched further (creating pwm from the core), because I switched to an octal DAC for my project.

Solved.
HardwareTimer pwmtimer(2);
void setup() {
// pinMode(11, INPUT_ANALOG);
// Serial.begin(115200);
pinMode(PA1, PWM);
pwmtimer.setPrescaleFactor(1);
pwmtimer.setPeriod(50);
}

melodic wrote:Solved.

Hi Roger & All,

I am looking for complementary PWM output from a couple of pins, as part of my micro-solar inverter project

Has anyone got code to support this timer mode – that is compatible with PWMwrite function?

Thanks in advance

Ken

monsonite wrote:Hi Roger & All,
I am looking for complementary PWM output from a couple of pins, as part of my micro-solar inverter project
Has anyone got code to support this timer mode – that is compatible with PWMwrite function?
Thanks in advance
Ken

Thanks Ray,

I really just wanted to know if the means to select the complimentary mode was included within the “Leaf Labs” library implementation.

Ken

monsonite wrote:Thanks Ray,
I really just wanted to know if the means to select the complimentary mode was included within the “Leaf Labs” library implementation.
Ken

How do we want to produce up to 100 kHz with maple . How do I need PWM frequency calculations

@ismail.cal

Don’t cross post.

Several people have replied to your other thread.

I will remove your posting to this thread as its unnecessary

melodic wrote:Solved.
HardwareTimer pwmtimer(2);
void setup() {
// pinMode(11, INPUT_ANALOG);
// Serial.begin(115200);
pinMode(PA1, PWM);
pwmtimer.setPrescaleFactor(1);
pwmtimer.setPeriod(50);
}

Hi Dave!
You code does not work, because you pwmWrite is in the loop and it is permanently overwriting the signal.

Here is a code which work

#define PWM_OUT PA8 //PWM output
#define PWM_OUT_COMP PB13 //complementary output
void setup(){

// initialize digital pin PC13 as an output.
pinMode(PC13, OUTPUT);
HardwareTimer timer1 = HardwareTimer(1);

timer1.setPrescaleFactor(1);
timer1.setPeriod(2041); //490
//timer1.setPeriod(10); //100kHz

pinMode(PWM_OUT, PWM); //Ideally these would be done as bit wise as I dont know exactly whats being set here..
pinMode(PWM_OUT_COMP, PWM);

timer_dev *t = TIMER1; //refers t to Timer 8 memory location, how to read back?
timer_reg_map r = t->regs;

bitSet(r.adv->CCER,0); //this should enable complimentary outputs
bitSet(r.adv->CCER,2);
pwmWrite(PWM_OUT, 10); //

}

void loop(){

// I am alive
digitalWrite(PC13, HIGH); // turn the LED on (HIGH is the voltage level)
//digitalWrite(PA5, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(PC13, LOW); // turn the LED off by making the voltage LOW
//digitalWrite(PA5, LOW); // turn the LED off by making the voltage LOW
delay(1000);
}