ESP32 PCNT

Development Libraries
1

Is there a way to use PCNT on the ESP32 under the Arduino IDE? I can find it for the Espressif IDF, but I haven't been able to find a way to use it yet under Arduino.

2

Did you find any example? I see a pcnt.h file in arduino core:
https://github.com/espressif/arduino-esp32/blob/master/tools/sdk/include/driver/driver/pcnt.h

3

Maybe we can "merge" these two snippets into an ESP32-working source:

OpenEnergyMonitor Arduino pulse counter:

//Number of pulses, used to measure energy.
long pulseCount = 0;

//Used to measure power.
unsigned long pulseTime,lastTime;

//power and energy
double power, elapsedkWh;

//Number of pulses per wh - found or set on the meter.
int ppwh = 1; //1000 pulses/kwh = 1 pulse per wh

void setup()
{
    Serial.begin(115200);

    // KWH interrupt attached to IRQ 1 = pin3
    attachInterrupt(1, onPulse, FALLING);
}

void loop()
{

}

// The interrupt routine
void onPulse()
{
    //used to measure time between pulses.
    lastTime = pulseTime;
    pulseTime = micros();

    //pulseCounter
    pulseCount++;

    //Calculate power
    power = (3600000000.0 / (pulseTime - lastTime))/ppwh;

    //Find kwh elapsed
    elapsedkWh = (1.0*pulseCount/(ppwh*1000)); //multiply by 1000 to convert pulses per wh to kwh

    //Print the values.
    Serial.print(power,4);
    Serial.print(" ");
    Serial.println(elapsedkWh,3);
}

https://learn.openenergymonitor.org/electricity-monitoring/pulse-counting/interrupt-based-pulse-counter

ESP32 GPIO interrupt manager:

#include <Arduino.h>

struct Button {
    const uint8_t PIN;
    uint32_t numberKeyPresses;
    bool pressed;
};

Button button1 = {23, 0, false};
Button button2 = {18, 0, false};

void IRAM_ATTR isr(void* arg) {
    Button* s = static_cast<Button*>(arg);
    s->numberKeyPresses += 1;
    s->pressed = true;
}

void IRAM_ATTR isr() {
    button2.numberKeyPresses += 1;
    button2.pressed = true;
}

void setup() {
    Serial.begin(115200);
    pinMode(button1.PIN, INPUT_PULLUP);
    attachInterruptArg(button1.PIN, isr, &button1, FALLING);
    pinMode(button2.PIN, INPUT_PULLUP);
    attachInterrupt(button2.PIN, isr, FALLING);
}

void loop() {
    if (button1.pressed) {
        Serial.printf("Button 1 has been pressed %u times\n", button1.numberKeyPresses);
        button1.pressed = false;
    }
    if (button2.pressed) {
        Serial.printf("Button 2 has been pressed %u times\n", button2.numberKeyPresses);
        button2.pressed = false;
    }
    static uint32_t lastMillis = 0;
    if (millis() - lastMillis > 10000) {
      lastMillis = millis();
      detachInterrupt(button1.PIN);
    }
}