added the ability to printf %i

Author: gijsio

py/mpprint.c

@@ -1,3 +1,12 @@
+
+/*
+ * Copyright (c) 2020, Pycom Limited.
+ *
+ * This software is licensed under the GNU GPL version 3 or any
+ * later version, with permitted additional terms. For more information
+ * see the Pycom Licence v1.0 document supplied with this file, or
+ * available at https://www.pycom.io/opensource/licensing
+ */
 /*
  * This file is part of the MicroPython project, http://micropython.org/
  *
@@ -503,7 +512,8 @@ int mp_vprintf(const mp_print_t *print, const char *fmt, va_list args) {
                 chrs += mp_print_strn(print, str, prec, flags, fill, width);
                 break;
             }
-            case 'd': {
+            case 'd': 
+            case 'i': {
                 mp_int_t val;
                 if (long_arg) {
                     val = va_arg(args, long int);