Added upsideDown() function for rotating all content 180 degrees.

README.md

@@ -29,6 +29,7 @@ printer.openCashDrawer();                                  // Kick the cash draw
 printer.cut();                                             // Cuts the paper (if printer only supports one mode use this)
 printer.partialCut();                                      // Cuts the paper leaving a small bridge in middle (if printer supports multiple cut modes)
 printer.beep();                                            // Sound internal beeper/buzzer (if available)
+printer.upsideDown(true);                                  // Content is printed upside down (rotated 180 degrees)
 
 printer.bold(true);                                 // Set text bold
 printer.invert(true);                               // Background/text color inversion

configs/epsonConfig.js

@@ -12,6 +12,8 @@ module.exports = {
     HW_SELECT  : new Buffer([0x1b, 0x3d, 0x01]),      // Printer select
     HW_RESET   : new Buffer([0x1b, 0x3f, 0x0a, 0x00]),  // Reset printer hardware
     BEEP       : new Buffer([0x1b, 0x1e]),              // Sounds built-in buzzer (if equipped)
+    UPSIDE_DOWN_ON  : new Buffer([0x1b,0x7b,0x01]),     // Upside down printing ON (rotated 180 degrees).
+    UPSIDE_DOWN_OFF : new Buffer([0x1b,0x7b,0x00]),     // Upside down printing OFF (default).
 
     // Cash Drawer
     CD_KICK_2  : new Buffer([0x1b, 0x70, 0x00]),      // Sends a pulse to pin 2 []

node-thermal-printer.js

@@ -125,6 +125,15 @@ module.exports = {
     else append(config.TXT_UNDERL_OFF);
   },
 
+  upsideDown: function(enabled){
+     if (printerConfig.type == 'star'){
+      console.error("Upside down not supported on STAR yet");
+      return;
+    }
+    if(enabled) append(config.UPSIDE_DOWN_ON);
+    else append(config.UPSIDE_DOWN_OFF);
+  },
+
   invert: function(enabled){
     if (printerConfig.type == 'star'){
       console.error("Invert not supported on STAR yet");