Interrupt Handling

The driver keeps default behavior in serviceAllInterrupts() (updates global flags), and also supports user callbacks. For IRQ-driven sketches, prefer servicePendingInterrupts() in loop().

Interrupt Usage

Wire MAX30001G INTB (and optional INT2B) to interrupt-capable GPIO pins and pass those pins to the constructor.

const uint8_t AFE_CS_PIN  = 10;
const int AFE_INT1_PIN = 2;   // INTB
const int AFE_INT2_PIN = -1;  // INT2B optional, -1 if unused
 
MAX30001G afe(AFE_CS_PIN, AFE_INT1_PIN, AFE_INT2_PIN);
 
void setup() {
  // Constructor attaches ISR handlers for valid interrupt pins.
  // Choose which status events drive INT1/INT2:
  afe.setInterrupt1(true,  true,  true,  false, false);  // ECG + BIOZ + RTOR on INT1
  afe.setInterrupt2(false, false, false, false, false);  // INT2 disabled
}
 
void loop() {
  if (afe.servicePendingInterrupts()) {
    // STATUS was serviced and global flags/callbacks are up to date.
  }
}

servicePendingInterrupts() uses Arduino core APIs noInterrupts() and interrupts() to atomically read/clear the software pending flags. These APIs are available on AVR, SAMD, ESP8266, and ESP32 Arduino cores, so no API change is needed for ESP-type boards.

If your board does not wire interrupt pins, call serviceAllInterrupts() periodically instead. If you provide your own ISR, set library globals afe_irq_pending and afe_irq1_pending/afe_irq2_pending (do not use a separate local pending flag). If you use latched event/fault globals, clear them explicitly with clearLatchedStatusFlags() after handling.

Configure which events drive INT1/INT2

setInterrupt1(...) and setInterrupt2(...) program MAX30001G EN_INT1 and EN_INT2.

Example:

// INT1: ECG + BIOZ FIFO related interrupts
afe.setInterrupt1(true,  true,  false, false, false);
// INT2: R-to-R interrupt
afe.setInterrupt2(false, false, true,  false, false);

Available per-event callbacks (<tt>InterruptEvent</tt>)

• MAX30001G::IRQ_ECG_FIFO -> MAX30001_STATUS_EINT
• MAX30001G::IRQ_ECG_OVF -> MAX30001_STATUS_EOVF
• MAX30001G::IRQ_ECG_FAST -> MAX30001_STATUS_FSTINT
• MAX30001G::IRQ_ECG_LEADOFF -> MAX30001_STATUS_DCLOFFINT
• MAX30001G::IRQ_BIOZ_FIFO -> MAX30001_STATUS_BINT
• MAX30001G::IRQ_BIOZ_OVF -> MAX30001_STATUS_BOVF
• MAX30001G::IRQ_BIOZ_OVER -> MAX30001_STATUS_BOVER
• MAX30001G::IRQ_BIOZ_UNDER -> MAX30001_STATUS_BUNDR
• MAX30001G::IRQ_BIOZ_CGMON -> MAX30001_STATUS_BCGMON
• MAX30001G::IRQ_LEADS_ON -> MAX30001_STATUS_LONINT
• MAX30001G::IRQ_RTOR -> MAX30001_STATUS_RRINT
• MAX30001G::IRQ_PLL_UNLOCK -> MAX30001_STATUS_PLLINT

Example: Individual ECG and BIOZ FIFO callbacks

void onEcgFifo(MAX30001G* dev, uint32_t status, void* ctx) {
  (void)status;
  (void)ctx;
  dev->handleECGFifoInterrupt(false);   // pushes samples into global ECG_data
}
 
void onBiozFifo(MAX30001G* dev, uint32_t status, void* ctx) {
  (void)status;
  (void)ctx;
  dev->handleBIOZFifoInterrupt(false);  // pushes samples into global BIOZ_data
}
 
void setup() {
  afe.setInterruptEventCallback(MAX30001G::IRQ_ECG_FIFO,  onEcgFifo);
  afe.setInterruptEventCallback(MAX30001G::IRQ_BIOZ_FIFO, onBiozFifo);
}

Example: One aggregate callback

void onAfeAggregate(MAX30001G* dev, uint32_t status, void* ctx) {
  (void)ctx;
 
  if (status & MAX30001_STATUS_EINT)  { dev->handleECGFifoInterrupt(false); }
  if (status & MAX30001_STATUS_BINT)  { dev->handleBIOZFifoInterrupt(false); }
  if (status & MAX30001_STATUS_RRINT) { dev->handleRtoRInterrupt(); }
}
 
void setup() {
  const uint32_t mask = MAX30001_STATUS_EINT | MAX30001_STATUS_BINT | MAX30001_STATUS_RRINT;
  afe.setInterruptAggregateCallback(onAfeAggregate, nullptr, mask);
}

If aggregate and individual callbacks are both registered, aggregate runs first.

Interrupt Callback API summary

• setInterruptEventCallback(event, cb, context)
• clearInterruptEventCallback(event)
• setInterruptAggregateCallback(cb, context, statusMask)
• clearInterruptAggregateCallback()
• clearAllInterruptCallbacks()
• clearLatchedStatusFlags()