Function for MicroPython on ESP32 which generates PWM signal on given pin. Based on: http://docs.micropython.org/en/latest/esp8266/quickref.html#pwm-pulse-width-modulation

ledPulse.py

def do_led_pulse(nPulses, pin):
    import machine
    import time, math
    led = machine.PWM(machine.Pin(pin), freq=1000)
    for j in range(pulses):
        for i in range(20):
                led.duty(int(math.sin(i / 10 * math.pi) * 500 + 500))
                time.sleep_ms(50)