Submit transfer works, callbacks work. Need to interpret data

hanvon-libusb.c

@@ -68,7 +68,7 @@ struct hanvon {
 void callback(struct libusb_transfer *transfer) {
   int i = 0;
   for(; i < 10; i++) {
-    printf("%c, ", transfer -> buffer[i]);
+    printf("0x%x, ", transfer -> buffer[i]);
   }
   printf("placeholder\n");
 }
@@ -149,32 +149,32 @@ int main()
 		return 0;	
 	}
 
-	printf("Got to this point\n");
-
-
 	// Wait and handle interrupts?
-	struct libusb_transfer tx;
+	struct libusb_transfer *tx;
 
 	const int ENDPOINT_ADDR = 0x81; // bEndpointAddress from lsusb -v
 	const unsigned int LEN = 10;    // wMaxPacketSize from lsusb -v
 	unsigned char buffer[LEN];
-	// assign timeout of 1s, for any action is too much as is
-	libusb_fill_interrupt_transfer(	&tx, 
+
+  // Allocate memory for transfer, configure, then submit
+  tx = libusb_alloc_transfer(0);
+	libusb_fill_interrupt_transfer(	tx, 
 					h, 
 					ENDPOINT_ADDR, 
 					buffer, 
 					LEN,
 					callback,
 					NULL, 
-					130); // milliseconds
+					130); // timeout in milliseconds
+
+    do {
+	    state = libusb_submit_transfer(tx);
+	    if (state < 0 ) {
+		    return state;
+      }
+      libusb_handle_events(NULL);
+    } while (1);
 
-	state = libusb_submit_transfer(&tx);
-	if (state < 0 ) {
-		return state;
-	}
-    for(;;) {
-        libusb_handle_events(NULL);
-    }
     return state;
 }