adjust Arduino examples to use interrupts when applicable

examples/absolute_mode/absolute_mode.ino

@@ -16,6 +16,15 @@ PinnacleTouchSPI trackpad(DR_PIN, SS_PIN);
 // an object to hold data reported by the Cirque trackpad
 AbsoluteReport data;
 
+#if DR_PIN != PINNACLE_SW_DR
+// track the interrupts with our own IRQ flag
+volatile bool isDataReady = false;
+
+void interruptHandler() {
+  isDataReady = true;
+}
+#endif  // using DR_PIN
+
 void setup() {
   Serial.begin(115200);
   while (!Serial) {
@@ -30,6 +39,10 @@ void setup() {
   Serial.println(F("CirquePinnacle/examples/absolute_mode"));
   trackpad.setDataMode(PINNACLE_ABSOLUTE);
   trackpad.absoluteModeConfig(1);  // set count of z-idle packets to 1
+#if DR_PIN != PINNACLE_SW_DR
+  // pinMode() is already called by trackpad.begin()
+  attachInterrupt(digitalPinToInterrupt(DR_PIN), interruptHandler, FALLING);
+#endif  // using DR_PIN
   Serial.println(F("\n*** Enter 'M' to measure and print raw data."));
   Serial.println(F("*** Enter 'T' to measure and print trigonometric calculations.\n"));
   Serial.println(F("Touch the trackpad to see the data."));
@@ -43,14 +56,20 @@ raw data (false) or trigonometry data (true)
 */
 bool onlyShowTrigVals = false;
 
-#ifndef M_PI
+#if defined(M_PI) && !defined(PI)
 #define PI M_PI
-#else
+#endif
+#ifndef PI
 #define PI 3.14159
 #endif
 
 void loop() {
+#if DR_PIN == PINNACLE_SW_DR  // not using DR_PIN
   if (trackpad.available()) {
+#else   // using interruptHandler()
+  if (isDataReady) {
+    isDataReady = false;  // reset our IRQ flag
+#endif  // using DR_PIN
     trackpad.read(&data);
 
     // datasheet recommends clamping the axes value to reliable range

examples/anymeas_mode/anymeas_mode.ino

@@ -48,6 +48,18 @@ void compensate() {
   }
 }
 
+// track the interrupts with our own IRQ flag
+volatile bool isDataReady = false;
+
+// a flag to control iteration of our loop()
+bool waitingForInterrupt = false;
+// the index number used to iterate through our vectorDeterminants array used in loop()
+unsigned int vectorIndex = 0;
+
+void interruptHandler() {
+  isDataReady = true;
+}
+
 void setup() {
   Serial.begin(115200);
   while (!Serial) {
@@ -63,20 +75,36 @@ void setup() {
   trackpad.setDataMode(PINNACLE_ANYMEAS);
   trackpad.anymeasModeConfig();
   compensate();
+  // pinMode() is already called by trackpad.begin()
+  attachInterrupt(digitalPinToInterrupt(DR_PIN), interruptHandler, FALLING);
   Serial.println(F("starting in 5 seconds..."));
   delay(5000);
 }
 
 void loop() {
-  for (uint8_t i = 0; i < variousVectors_size; i++) {
-    int16_t measurement = trackpad.measureAdc(vectorDeterminants[i].toggle,
-                                              vectorDeterminants[i].polarity);
-    measurement -= compensations[i];
+  if (!isDataReady && !waitingForInterrupt) {
+    trackpad.startMeasureAdc(
+      vectorDeterminants[vectorIndex].toggle,
+      vectorDeterminants[vectorIndex].polarity);
+    waitingForInterrupt = true;
+  } else if (isDataReady) {
+    isDataReady = false;          // reset our IRQ flag
+    waitingForInterrupt = false;  // allow iteration to continue
+
+    int16_t measurement = trackpad.getMeasureAdc();
+    measurement -= compensations[vectorIndex];
     Serial.print(F("meas"));
-    Serial.print(i);
+    Serial.print(vectorIndex);
     Serial.print(F(":"));
     Serial.print(measurement);
     Serial.print(F("  \t"));
+
+    // increment our loop iterator
+    if (vectorIndex < (variousVectors_size - 1)) {
+      vectorIndex++;
+    } else {
+      vectorIndex = 0;
+      Serial.println();
+    }
   }
-  Serial.println();
 }

examples/relative_mode/relative_mode.ino

@@ -15,6 +15,15 @@ PinnacleTouchSPI trackpad(DR_PIN, SS_PIN);
 // an object to hold data reported by the Cirque trackpad
 RelativeReport data;
 
+#if DR_PIN != PINNACLE_SW_DR
+// track the interrupts with our own IRQ flag
+volatile bool isDataReady = false;
+
+void interruptHandler() {
+  isDataReady = true;
+}
+#endif  // using DR_PIN
+
 void setup() {
   Serial.begin(115200);
   while (!Serial) {
@@ -29,11 +38,21 @@ void setup() {
   Serial.println(F("CirquePinnacle/examples/relative_mode"));
   trackpad.setDataMode(PINNACLE_RELATIVE);
   trackpad.relativeModeConfig();  // uses default config
+#if DR_PIN != PINNACLE_SW_DR
+  // pinMode() is already called by trackpad.begin()
+  attachInterrupt(digitalPinToInterrupt(DR_PIN), interruptHandler, FALLING);
+#endif  // using DR_PIN
   Serial.println(F("Touch the trackpad to see the data."));
 }
 
 void loop() {
+
+#if DR_PIN == PINNACLE_SW_DR  // not using DR_PIN
   if (trackpad.available()) {
+#else   // using interruptHandler()
+  if (isDataReady) {
+    isDataReady = false;  // reset our IRQ flag
+#endif  // using DR_PIN
     trackpad.read(&data);
     Serial.print(F("Left:"));
     Serial.print(data.buttons & 1);

examples/usb_mouse/usb_mouse.ino

@@ -12,6 +12,15 @@ PinnacleTouchSPI trackpad(DR_PIN, SS_PIN);
 // an object to hold data reported by the Cirque trackpad
 RelativeReport data;
 
+#if DR_PIN != PINNACLE_SW_DR
+// track the interrupts with our own IRQ flag
+volatile bool isDataReady = false;
+
+void interruptHandler() {
+  isDataReady = true;
+}
+#endif  // using DR_PIN
+
 const uint32_t interval = 750;  // milliseconds used to blink LED
 uint32_t lastLedChange = 0;     // millis() since last digitalWrite()
 bool ledState = false;          // last state sent to digitalWrite()
@@ -31,15 +40,23 @@ void setup() {
   trackpad.setDataMode(PINNACLE_RELATIVE);  // ensure mouse mode is enabled
   // tell the Pinnacle ASIC to rotate the orientation of the axis data by +90 degrees
   trackpad.relativeModeConfig(true, true);  // (enable taps, rotate90)
-
+#if DR_PIN != PINNACLE_SW_DR
+  // pinMode() is already called by trackpad.begin()
+  attachInterrupt(digitalPinToInterrupt(DR_PIN), interruptHandler, FALLING);
+#endif  // using DR_PIN
 
   digitalWrite(LED, LOW);
   lastLedChange = millis();
 }
 
 void loop() {
 
-  if (trackpad.available()) {  // is there new data?
+#if DR_PIN == PINNACLE_SW_DR  // not using DR_PIN
+  if (trackpad.available()) {
+#else   // using interruptHandler()
+  if (isDataReady) {
+    isDataReady = false;  // reset our IRQ flag
+#endif  // using DR_PIN
 
     // save buttons' previous state before getting updates
     uint8_t prevButtonStates = data.buttons;  // for edge detection