Clarify Serial library return values

gohai · gohai · commit 983817026c19 · 2016-10-29T01:20:33.000+02:00
Addresses #487.
diff --git a/content/api_en/LIB_serial/Serial_last.xml b/content/api_en/LIB_serial/Serial_last.xml
@@ -36,7 +36,7 @@ void draw() {
 </example>
 
 <description><![CDATA[
-Returns last byte received.
+Returns last byte received or -1 if there is none available.
 ]]></description>
 
 
diff --git a/content/api_en/LIB_serial/Serial_lastChar.xml b/content/api_en/LIB_serial/Serial_lastChar.xml
@@ -37,7 +37,7 @@ void draw() {
 </example>
 
 <description><![CDATA[
-Returns the last byte received as a char.
+Returns the last byte received as a char or -1 if there is none available.
 ]]></description>
 
 
diff --git a/content/api_en/LIB_serial/Serial_readBytes.xml b/content/api_en/LIB_serial/Serial_readBytes.xml
@@ -42,7 +42,7 @@ void draw() {
 </example>
 
 <description><![CDATA[
-Reads a group of bytes from the buffer. The version with no parameters returns a byte array of all data in the buffer. This is not efficient, but is easy to use. The version with the <b>byteBuffer</b> parameter is more memory and time efficient. It grabs the data in the buffer and puts it into the byte array passed in and returns an int value for the number of bytes read. If more bytes are available than can fit into the <b>byteBuffer</b>, only those that fit are read.
+Reads a group of bytes from the buffer or <b>null</b> if there are none available. The version with no parameters returns a byte array of all data in the buffer. This is not efficient, but is easy to use. The version with the <b>byteBuffer</b> parameter is more memory and time efficient. It grabs the data in the buffer and puts it into the byte array passed in and returns an int value for the number of bytes read. If more bytes are available than can fit into the <b>byteBuffer</b>, only those that fit are read.
 ]]></description>
 
 
diff --git a/content/api_en/LIB_serial/Serial_readString.xml b/content/api_en/LIB_serial/Serial_readString.xml
@@ -38,7 +38,7 @@ void draw() {
 </example>
 
 <description><![CDATA[
-Returns all the data from the buffer as a String. This method assumes the incoming characters are ASCII. If you want to transfer Unicode data, first convert the String to a byte stream in the representation of your choice (i.e. UTF8 or two-byte Unicode data), and send it as a byte array.
+Returns all the data from the buffer as a String or <b>null</b> if there is nothing available. This method assumes the incoming characters are ASCII. If you want to transfer Unicode data, first convert the String to a byte stream in the representation of your choice (i.e. UTF8 or two-byte Unicode data), and send it as a byte array.
 ]]></description>
 
 
