got it so the gyro should work
I basically split the linear code from the gyro board up into a state
machine that runs in ISRs.
diff --git a/bbb_cape/src/cape/led.h b/bbb_cape/src/cape/led.h
new file mode 100644
index 0000000..ee47853
--- /dev/null
+++ b/bbb_cape/src/cape/led.h
@@ -0,0 +1,17 @@
+#ifndef CAPE_LED_H_
+#define CAPE_LED_H_
+
+// The LEDs as referenced by the silkscreen.
+enum LED {
+ LED_ERR,
+ LED_HB,
+ LED_Z,
+ LED_DB,
+};
+
+// Turns the indicated LED on or off.
+void led_set(enum LED led, int on);
+
+void led_init(void);
+
+#endif // CAPE_LED_H_