Made the maximum chunk height configurable with setMaxChunkHeight(int…

… val) - defaults to 255

Adafruit_Thermal.cpp

@@ -184,6 +184,7 @@ void Adafruit_Thermal::begin(int heatTime) {
 
   dotPrintTime = 30000; // See comments near top of file for
   dotFeedTime  =  2100; // an explanation of these values.
+  maxChunkHeight = 255;
 }
 
 // Reset printer to default state.
@@ -395,10 +396,10 @@ void Adafruit_Thermal::printBitmap(
   rowBytes        = (w + 7) / 8; // Round up to next byte boundary
   rowBytesClipped = (rowBytes >= 48) ? 48 : rowBytes; // 384 pixels max width
 
-  for(i=rowStart=0; rowStart < h; rowStart += 255) {
+  for(i=rowStart=0; rowStart < h; rowStart += maxChunkHeight) {
     // Issue up to 255 rows at a time:
     chunkHeight = h - rowStart;
-    if(chunkHeight > 255) chunkHeight = 255;
+    if(chunkHeight > maxChunkHeight) chunkHeight = maxChunkHeight;
 
     writeBytes(18, 42, chunkHeight, rowBytesClipped);
 
@@ -419,10 +420,10 @@ void Adafruit_Thermal::printBitmap(int w, int h, Stream *stream) {
   rowBytes        = (w + 7) / 8; // Round up to next byte boundary
   rowBytesClipped = (rowBytes >= 48) ? 48 : rowBytes; // 384 pixels max width
 
-  for(rowStart=0; rowStart < h; rowStart += 255) {
+  for(rowStart=0; rowStart < h; rowStart += maxChunkHeight) {
     // Issue up to 255 rows at a time:
     chunkHeight = h - rowStart;
-    if(chunkHeight > 255) chunkHeight = 255;
+    if(chunkHeight > maxChunkHeight) chunkHeight = maxChunkHeight;
 
     writeBytes(18, 42, chunkHeight, rowBytesClipped);
 
@@ -538,6 +539,10 @@ void Adafruit_Thermal::setLineHeight(int val) {
   writeBytes(27, 51, val);
 }
 
+void Adafruit_Thermal::setMaxChunkHeight(int val) {
+  maxChunkHeight = val;
+}
+
 ////////////////////// not working?
 void Adafruit_Thermal::tab() {
   PRINTER_PRINT(9);

Adafruit_Thermal.h

@@ -97,6 +97,7 @@ class Adafruit_Thermal : public Print {
     timeoutSet(unsigned long),
     timeoutWait(),
     setTimes(unsigned long, unsigned long),
+    setMaxChunkHeight(int val),
 
     setCharSpacing(int spacing), // Not working
     tab();                       // Not working
@@ -127,7 +128,8 @@ class Adafruit_Thermal : public Print {
   int
     printMode,
     _RX_Pin,
-    _TX_Pin;
+    _TX_Pin,
+    maxChunkHeight;
   void
     setPrintMode(uint8_t mask),
     unsetPrintMode(uint8_t mask),