198 MAKING THINGS TALK An XBee Serial Terminal Because the GNU screen program in Mac OS X, Unix, and Linux doesn't print newlines when the XBees send only a return character, it can be difficult to read the results. 8 Here's a Processing program /* XBee terminal language: processing This program is a basic serial terminal program. It replaces newline characters from the keyboard with return characters. It's designed for use with Linux, Unix, and Mac OS X in combination with XBee radios, because the XBees don't send newline characters back. */ import processing.serial.*; that substitutes newlines for return characters when it prints the results onscreen. GNU screen users may find it useful in place of screen for commu- nicating with XBee radios. Figure 6-10 shows a screenshot of the XBee terminal program.