Add some motor support

libs/core/output.cpp

@@ -0,0 +1,21 @@
+#include "pxt.h"
+#include "ev3.h"
+
+namespace output {
+
+/**
+ * Create a new zero-initialized buffer.
+ * @param size number of bytes in the buffer
+ */
+//%
+Buffer createBuffer(int size) {
+    return mkBuffer(NULL, size);
+}
+
+extern "C" int WriteToPWMDevice(char *bytes, int num_bytes);
+
+//%
+void writePWM(Buffer buf) {
+    WriteToPWMDevice((char*)buf->data, buf->length);
+}
+}