new_pwm: sporadical flashing/flickering

[verybadsoldier]

I have been using the ESP-PWM for quite a while in this project (LED controller): https://github.com/verybadsoldier/esp_rgbww_firmware

The PWM is in my opinion 100% smooth and stable as I did not notice any flaws in in the past.

Now I am in the process of upgrading to Sming 3.7.0, ESP SDK 3.0.0 and to use new_pwm instead of SDK-PWM. It is working smoothly now but I noticed that the PWM produced by new_pwm is less stable compared to SDK-PWM. When fading I see very short flashes every few seconds.

The effect is also visible in the demo Basic_HwPWM. I modified it slightly to this:

#include <user_config.h>
#include <SmingCore/SmingCore.h>
#include <HardwarePWM.h>

uint8_t pins[8] = {4, 5, 0, 2, 15, 13, 12, 14}; // List of pins that you want to connect to pwm
HardwarePWM HW_pwm(pins, 8);

Timer procTimer;
int32 i = 0;
bool countUp = true;

int maxDuty = HW_pwm.getMaxDuty();
int32 inc = maxDuty / 15;

void doPWM()
{
        if(countUp == true) {
                i += inc;
                if(i >= maxDuty) {
                        i = maxDuty;
                        countUp = false;
                }
        } else {
                i -= inc;
                if(i <= 0) {
                        i = 0;
                        countUp = true;
                }
        }
        HW_pwm.analogWrite(14, i);
}

void init()
{
        Serial.begin(SERIAL_BAUD_RATE); // 115200 by default
        Serial.systemDebugOutput(true); // Enable debug output to serial

        const int period = int(float(1000)/(float(339)/float(1000)));
        HW_pwm.setPeriod(period);

        maxDuty = HW_pwm.getMaxDuty();

        // WIFI not needed for demo. So disabling WIFI.
        WifiStation.enable(false);
        WifiAccessPoint.enable(false);

        // Setting PWM values on 8 different pins
        HW_pwm.analogWrite(14, maxDuty);

        debugf("PWM output set on all 8 Pins. Kindly check...");
        debugf("Now Pin 2 will go from 0 to VCC to 0 in cycles.");
        procTimer.initializeMs(50, doPWM).start();
}

When running, every couple of seconds a subtle flashing of the LED is visible. It is really short, like the blink of an eye but it is noticable. I tested several times back and forth and the SDK-PWM does not show this effect using same code.

It might be related or even identical to this: https://github.com/StefanBruens/ESP8266_new_pwm/issues/9

The hardware used for the LED controller is described here (might be relevant): https://github.com/patrickjahns/esp_rgbww_controller

[slaff]

@verybadsoldier did you notice any improvement with the latest develop code?

[verybadsoldier]

I am not using new_pwm anymore due to this flickering problem so I cannot say. Also I am still on 3.8.0. But as far as I know there were no commits to new_pwm in ages so I don't think the chances of a changed behavior is very high.