First init.

libraries/Adafruit_seesaw_Library/examples/digital/gpio_interrupts/gpio_interrupts.ino

@@ -0,0 +1,39 @@
+/*
+ * This example shows how set GPIO interrupts on a seesaw.
+ */
+
+#include "Adafruit_seesaw.h"
+
+//connect the interrupt pin on the seesaw (pin 8 on samd09 breakout) to this pin on your arduino
+#define INT_PIN 3
+
+//the interrupt will fire when this pin on the seesaw changes state 
+#define SCAN_PIN 9
+
+Adafruit_seesaw ss;
+
+uint32_t mask = ((uint32_t)0b1 << SCAN_PIN);
+
+void setup() {
+  Serial.begin(115200);
+  
+  while (!Serial) delay(10);   // wait until serial port is opened
+  
+  if(!ss.begin()){
+    Serial.println(F("seesaw not found!"));
+    while(1) delay(10);
+  }
+  
+  Serial.println(F("seesaw started OK!"));
+
+  pinMode(INT_PIN, INPUT_PULLUP);
+  ss.pinModeBulk(mask, INPUT_PULLUP);
+  ss.setGPIOInterrupts(mask, 1);
+}
+
+void loop() {
+  if(!digitalRead(INT_PIN)){
+    Serial.print(F("Interrupt fired! pin state: "));
+    Serial.println(ss.digitalRead(SCAN_PIN));
+  }
+}