broke out interrupts into isr.cpp

fw/HackSpaceCon/src/isr.cpp

@@ -0,0 +1,37 @@
+#include <Arduino.h>
+
+
+extern uint8_t run_rgb_program;
+
+
+// TCB0 general interrupt
+ISR(TCB0_INT_vect)
+{
+    // reset the INTFLAGS - necessary on this series
+    uint8_t intflags = TCB0.INTFLAGS;
+    TCB0.INTFLAGS = intflags;
+
+    // in this program, this interrupt is only used for timing.
+    // we'll now return to executing loop()
+}
+
+// button interrupt
+ISR(PORTA_PORT_vect)
+{
+    // reset the INTFLAGS - necessary on this series
+    uint8_t intflags = PORTA.INTFLAGS;
+    PORTA.INTFLAGS = intflags;
+
+	// was our pin changed?
+    if (intflags & PIN3_bm) {
+		// is the pin low?
+		if (!digitalRead(PIN_PA3)) {
+			// start running a program if one isn't running already
+        	if (!run_rgb_program) run_rgb_program = 1;
+		} else if (run_rgb_program == 2) {
+			// if we're running a program when the button is released (likely),
+			// then skip this interrupt
+			run_rgb_program++;
+		}
+    }
+}