Is this lbrary exact the same as the TimerOne library, but for TimerTwo?

[Rimbaldo]

Hi! I'm driving a BLDC motor with 3 pwm pins. So I have to use Timer1 and Timer2 to adjust this pins at the same time. Is your library exactly the same as the TimerOne, library, adapted to the Timer2? I mean, Can I use the same functions for both? I noticed in your's there's a little difference on some names and commands... If I use both at the same time, with the right values, could I have the same output for Timer1 and Timer2 pins at the same frequencies, duties, at the same time?

[theAndreas]

Hi, yes my library is very simular to the Timer1. But Timer1 is a 16 Bit timer and Timer2 only 8 Bit. So the resolution is lower. But it should work.

[Rimbaldo]

Hi, yes my library is very simular to the Timer1. But Timer1 is a 16 Bit timer and Timer2 only 8 Bit. So the resolution is lower. But it should work.

Ok.. I´m testing timerone and your´s timertwo together now.. In the timeone library there´s this function that enables output pwm on a timer 1 pin, for instance, a led on pin 9:

Timer1.pwm(9, dutyCycle, period);

or with just the first two arguments, without period:

Timer1.pwm(9, dutyCycle);

It actuallys outputs a pwm signal on a led attached to pin 9, for instance.

But with yours, if I write the same code, but for timer2, like this:

Timer2.setPwmDuty(TimerTwo::PWM_PIN_11, dutycycle);

or

Timer2.enablePwm(TimerTwo::PWM_PIN_11, dutycycle);`

I get nothing on the led, and with a scope I see no pwm on the pin 11.. why is that? What can I do so it outputs a pwm signal that I can use just like the timer one library? Can you help me out on this? Thanks!

Here´s the complete code for timerone (pin9) that I want to use with timer two on pin 11

#include <TimerOne.h> // https://github.com/PaulStoffregen/TimerOne

// This example creates a PWM signal with a variable duty cycle.
// This scheme enforces a minimum pulse width at low duty cycles
// by varying the frequency and increasing the off times between
// pulses.
//
// this code was adapted from the TimerOne library example
// for a 25kHz fan
// https://github.com/PaulStoffregen/TimerOne/blob/master/examples/FanSpeed/FanSpeed.ino
//
// Minimum pulse width could be important for good torque from motors
// With a tau=L/R, a 5tau pulse width for a R=1.65ohm, L=3.2mH stepper
// would be tau=0.0032/1.65=1.9ms and 5L/R = 5*.0032/1.65=9.7ms
//

constexpr int fanPin = 9; // Uno Timer1 OC1A pin

// Set the high frequency period and the minimum pulse
// These settings work for the Wokwi chips-scope from
// https://github.com/Dlloydev/Wokwi-Chip-Scope
// scope demo config:
// https://wokwi.com/projects/359331973918199809
// 2000us & 400us looks good with 200us sampling rate >22Hz
// 80 &4 at 1us sampling rate >1Hz
// 20000us and 2000us at 1ms sample rate for 50Hz>3Hz
// 20 & 1 and a real scope for 50K operation
constexpr unsigned long basePeriod = 2000;
constexpr unsigned long minUs = 400;
// calculate the changeover from adjusting pulse width at const freq
// to adjusting the frequency at const pulse width:
constexpr float minDuty = 100.0 * minUs / basePeriod;

float dutyCycle = 0;
int lastA0 = 0;
void setup(void)
{
Timer1.initialize(basePeriod); // us
Serial.begin(9600);
}

void loop(void)
{
updateSettings();
delay(0);
}

void updateSettings(void) {
const int interval = 250;
static unsigned long last = -interval;
if (millis() - last < interval ) return;
last += interval;
int val = analogRead(A0);
if (val != lastA0) {
lastA0 = val;
dutyCycle = 100 * (1 - cos(PI / 2 * val / 1023)); // 0-100% with high res at low end
unsigned long myPeriod = 0;
Serial.print("PWM Fan, Duty Cycle = ");
Serial.println(dutyCycle);
if (dutyCycle > minDuty || dutyCycle == 0.0) {
myPeriod = basePeriod;
Timer1.setPeriod(myPeriod);
Timer1.pwm(fanPin, (dutyCycle * 1023UL / 100));
Serial.print((int)(dutyCycle * myPeriod / 100));
Serial.print("us pulse at Hz:");
Serial.println(1000000UL / myPeriod);

} else { // Set by minimum width:
  myPeriod = minUs * 100UL / dutyCycle;
  if(myPeriod > 1885292UL){ 
    myPeriod  = 1885292UL;
  }
  Timer1.setPeriod(myPeriod);
  Timer1.pwm(fanPin, (uint32_t)(dutyCycle * 1023UL / 100));
  Serial.print(minUs);
  Serial.print("us pulse / ");
  Serial.print(myPeriod);
  Serial.print("us period / Hz:");
  Serial.println(1.0e6 / myPeriod);
  Serial.print("Timer1.OCR1A:"); Serial.print(OCR1A);
  Serial.print(" / ICR1:");Serial.print(ICR1);
  Serial.print(" TCCR1B:0b");Serial.println(TCCR1B,BIN);

}

}

}

[theAndreas]

Timer2 must be explicitly started with the API start(). Could you please try this? Seems to me there is a difference between Timer1 and Timer2. Timer1 is automatically started by calling initialize(). This is not really clear from the documentation. After analyzing the Timer1 example: start() is never called. In my example, however, it is.

[Rimbaldo]

Hi! ok, I did like this, to make that code for both timers, and still the same result... the led on pin 11 never lits...

void setup(void) {
Timer1.initialize(basePeriod); // us

Timer2.init(basePeriod);
Timer2.start();
Timer2.enablePwm(TimerTwo::PWM_PIN_11, 127);

Serial.begin(9600);
}

... inside the code:

Timer1.setPeriod(myPeriod);
Timer1.pwm(ledPin9, (dutyCycle * 1023UL / 100));
Timer2.setPeriod(myPeriod);
Timer2.setPwmDuty(TimerTwo::PWM_PIN_11, (dutyCycle * 1023UL / 100));

Anything else I could try???

[theAndreas]

Ok this is strange. I will try it in the evening on the Arduino Board. As far as I have more information. I will let you know. Rimbaldo ***@***.***> schrieb am So., 25. Juni 2023, 14:13:

…

Hi! ok, I did like this, to make that code for both timers, and still the same result... the led on pin 11 never lits... void setup(void) { Timer1.initialize(basePeriod); // us Timer2.init(basePeriod); Timer2.start(); Timer2.enablePwm(TimerTwo::PWM_PIN_11, 127); Serial.begin(9600); } ... inside the code: Timer1.setPeriod(myPeriod); Timer1.pwm(ledPin9, (dutyCycle * 1023UL / 100)); Timer2.setPeriod(myPeriod); Timer2.setPwmDuty(TimerTwo::PWM_PIN_11, (dutyCycle * 1023UL / 100)); Anything else I could try??? — Reply to this email directly, view it on GitHub <#3 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABG65UZSBS2DM5VBR5DHSOLXNATOXANCNFSM6AAAAAAYE6PP2M> . You are receiving this because you commented.Message ID: ***@***.***>

[theAndreas]

Ok Pin 11 is wrong. Pin 3 is correct. Fixed also some other things. This code with the updated Timer.h and Timer.cpp is now working on my board:

#include <Arduino.h>
#include <TimerTwo.h>

void setup() {
  Timer2.init();
  Timer2.start();
  Timer2.enablePwm(TimerTwo::PWM_PIN_3, 10);
}

void loop() {
}