NittoBend双轴ADS传感器ESP32 Feather适配问题求助

Root Cause #

The Interrupt wdt timeout on CPU1 error stems from two main issues:

• The original demo's interrupt service routine (ISR) likely includes blocking operations (like I2C reads or serial prints) that exceed ESP32's interrupt watchdog timer limits.
• The nDRDY pin (GPIO32) configuration is missing a pull-up resistor—since the sensor's nDRDY is an open-drain output, this can lead to unstable interrupt triggers or no triggers at all.

Step-by-Step Fixes #

1. Correct Interrupt Pin Configuration

First, configure the nDRDY pin with a pull-up resistor to ensure stable signal detection:

#define NDRDY_PIN 32
#define NRST_PIN 15

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

  // Reset pin setup
  pinMode(NRST_PIN, OUTPUT);
  digitalWrite(NRST_PIN, HIGH); // Sensor reset is active-low

  // nDRDY pin setup with pull-up (critical for open-drain output)
  pinMode(NDRDY_PIN, INPUT_PULLUP);

  // Attach interrupt to trigger on falling edge (nDRDY goes low when data is ready)
  attachInterrupt(digitalPinToInterrupt(NDRDY_PIN), dataReadyISR, FALLING);
  
  // Run your existing sensor initialization code here
  if(initTwoAxisADS()) {
    Serial.println("Two Axis ADS initialization succeeded");
  } else {
    Serial.println("Initialization failed");
    while(1);
  }
}

2. Rewrite ISR to Be Non-Blocking

Replace the original heavy ads_data_callback with a minimal ISR that only sets a volatile flag. All data processing must happen in the main loop to avoid WDT timeouts:

volatile bool dataReady = false;

// Minimal ISR - only set flag and exit
void dataReadyISR() {
  dataReady = true;
}

void loop() {
  if(dataReady) {
    // Temporarily disable interrupt to prevent race conditions
    detachInterrupt(digitalPinToInterrupt(NDRDY_PIN));
    
    // Read and process sensor data here (use your existing read logic)
    float xAngle, yAngle;
    if(readTwoAxisAngles(&xAngle, &yAngle)) {
      Serial.print("X Angle: ");
      Serial.print(xAngle);
      Serial.print(" | Y Angle: ");
      Serial.println(yAngle);
    }
    
    // Reset flag and re-enable interrupt
    dataReady = false;
    attachInterrupt(digitalPinToInterrupt(NDRDY_PIN), dataReadyISR, FALLING);
  }

  // Keep other main loop tasks short to avoid delaying interrupt handling
}

3. Verify I2C Pin Mapping

Ensure your I2C initialization uses the correct pins for ESP32 Feather (default SDA=21, SCL=22). If using custom pins, explicitly initialize I2C:

Wire.begin(21, 22); // SDA pin, SCL pin

Critical Reminders #

• Never run serial or I2C operations inside an ISR: These are blocking and will trigger WDT timeouts on ESP32.
• Volatile flag requirement: The dataReady variable must be declared volatile to ensure the main loop detects updates from the ISR.
• Interrupt re-enabling: Always re-enable the interrupt after processing data to catch the next ready signal.

内容的提问来源于stack exchange，提问作者user29732056