got the gyro and adc (I think) working
diff --git a/bbb_cape/src/cape/util.c b/bbb_cape/src/cape/util.c
new file mode 100644
index 0000000..4f2d9e1
--- /dev/null
+++ b/bbb_cape/src/cape/util.c
@@ -0,0 +1,17 @@
+#include "cape/util.h"
+
+#include "cape/led.h"
+
+void led_write(uint32_t value, int bits) {
+  for (int i = -2; i < bits; ++i) {
+    led_set(LED_Z, i < 0);
+    for (int ii = 0; ii < 1000000; ++ii) {
+      led_set(LED_ERR, i >= 0 && ii < 500000);
+      if (i >= 0) {
+        led_set(LED_DB, value & (1 << i));
+      } else {
+        led_set(LED_DB, 0);
+      }
+    }
+  }
+}