1 files changed, 10 insertions, 0 deletions
diff --git a/app/util.c b/app/util.c
index 7f05a60..b0ffe53 100644
--- a/app/util.c
+++ b/app/util.c
@@ -55,3 +55,13 @@ unsigned le_bcd (uint8_t *d, unsigned s, unsigned e)
 }
 
 
+unsigned xtoi (char c)
+{
+  if ((c >= '0') && (c <= '9')) return c - '0';
+
+  if ((c >= 'a') && (c <= 'f')) return 0xa + (c - 'a');
+
+  if ((c >= 'A') && (c <= 'F')) return 0xA + (c - 'A');
+
+  return 0;
+}