diff --git a/examples/pn53x-tamashell-scripts/ReadMobib.sh b/examples/pn53x-tamashell-scripts/ReadMobib.sh
index 24a3330..c4dd43c 100755
--- a/examples/pn53x-tamashell-scripts/ReadMobib.sh
+++ b/examples/pn53x-tamashell-scripts/ReadMobib.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 cat << EOF | \
     pn53x-tamashell |\
diff --git a/examples/pn53x-tamashell-scripts/ReadNavigo.sh b/examples/pn53x-tamashell-scripts/ReadNavigo.sh
index 4a72600..13e6bf5 100755
--- a/examples/pn53x-tamashell-scripts/ReadNavigo.sh
+++ b/examples/pn53x-tamashell-scripts/ReadNavigo.sh
@@ -1,9 +1,9 @@
-#!/bin/bash
+#!/bin/sh
 
 ID=$(cat << EOF | \
     pn53x-tamashell |\
     grep -A1 "^Tx: 42  01  0b  3f  80" |\
-    grep -o -P "(?<=Rx: 00  ..  ..  )..  ..  ..  .."|sed 's/  //g'
+    sed -e '1d' -e "s/^Rx: 00  ..  ..  \(..  ..  ..  ..\).*/\1/" -e 's/  //g'
 # Timeouts
 3205000002
 # ListTarget ModeB
@@ -13,6 +13,11 @@ ID=$(cat << EOF | \
 EOF
 )
 
+if [ -z "$ID" ]; then
+	echo "Error: I was not abble to read Navigo ID" >&2
+	exit 1
+fi
+
 cat << EOF | \
     pn53x-tamashell |\
     awk '\