Grbl can now take advantage of the extra memory in the 328

Makefile

@@ -27,7 +27,7 @@
 #                is connected.
 # FUSES ........ Parameters for avrdude to flash the fuses appropriately.
 
-DEVICE     = atmega168
+DEVICE     = atmega328p
 CLOCK      = 16000000
 PROGRAMMER = -c avrisp2 -P usb
 OBJECTS    = main.o motion_control.o gcode.o spindle_control.o wiring_serial.o serial_protocol.o stepper.o \

script/stream.rb

@@ -26,16 +26,15 @@
 
 SerialPort.open('/dev/tty.FireFly-A964-SPP-1', 115200) do |sp|
   sp.write("\r\n\r\n");
-  sleep 5
+  sleep 1
   ARGV.each do |file|
     puts "Processing file #{file}"
-    prebuffer = $prebuffer ? 12 : 0
+    prebuffer = $prebuffer ? 20 : 0
     File.readlines(file).each do |line|
       next if line.strip == ''
       puts line.strip
       sp.write("#{line.strip}\r\n");
       if prebuffer == 0
-        sleep 0.1
         begin
           result = sp.gets.strip
           puts "Grbl >> #{result}" unless result == '' or result == 'ok'

serial_protocol.c

@@ -26,7 +26,7 @@
 #include <math.h>
 #include "nuts_bolts.h"
 #include <avr/pgmspace.h>
-#define LINE_BUFFER_SIZE 30
+#define LINE_BUFFER_SIZE 50
 
 char line[LINE_BUFFER_SIZE];
 uint8_t char_counter;
@@ -52,6 +52,7 @@ void sp_process()
   {
     if((c == '\n')) {  // Line is complete. Then execute!
       line[char_counter] = 0;
+      printString(line); printPgmString(PSTR("\r\n"));        
       gc_execute_line(line);
       char_counter = 0;
       prompt();

stepper.c

@@ -19,7 +19,7 @@
 */
 
 /* The timer calculations of this module informed by the 'RepRap cartesian firmware' by Zack Smith
-   and Philipp Tiefenbacher. The circle buffer implementation gleaned from the wiring_serial library 
+   and Philipp Tiefenbacher. The ring buffer implementation gleaned from the wiring_serial library 
    by David A. Mellis */
 
 #include "stepper.h"
@@ -32,7 +32,12 @@
 
 #include "wiring_serial.h"
 
+// Pick a suitable line-buffer size
+#ifdef __AVR_ATmega328P__
+#define LINE_BUFFER_SIZE 40   // Atmega 328 has one full kilobyte of extra RAM!
+#else
 #define LINE_BUFFER_SIZE 10
+#endif
 
 struct Line {
   uint32_t steps_x, steps_y, steps_z;
@@ -86,7 +91,11 @@ void st_buffer_line(int32_t steps_x, int32_t steps_y, int32_t steps_z, uint32_t
 // This timer interrupt is executed at the rate set with config_step_timer. It pops one instruction from
 // the line_buffer, executes it. Then it starts timer2 in order to reset the motor port after
 // five microseconds.
+#ifdef TIMER1_COMPA_vect
+SIGNAL(TIMER1_COMPA_vect)
+#else
 SIGNAL(SIG_OUTPUT_COMPARE1A)
+#endif
 {
   if(busy){ return; } // The busy-flag is used to avoid reentering this interrupt
 
@@ -158,7 +167,11 @@ SIGNAL(SIG_OUTPUT_COMPARE1A)
 
 // This interrupt is set up by SIG_OUTPUT_COMPARE1A when it sets the motor port bits. It resets
 // the motor port after a short period (settings.pulse_microseconds) completing one step cycle.
+#ifdef TIMER2_OVF_vect
+SIGNAL(TIMER2_OVF_vect)
+#else
 SIGNAL(SIG_OVERFLOW2)
+#endif
 {
   // reset stepping pins (leave the direction pins)
   STEPPING_PORT = (STEPPING_PORT & ~STEP_MASK) | (settings.invert_mask & STEP_MASK); 

wiring_serial.c

@@ -39,7 +39,6 @@ int rx_buffer_tail = 0;
 
 void beginSerial(long baud)
 {
-#if defined(__AVR_ATmega168__)
 	UBRR0H = ((F_CPU / 16 + baud / 2) / baud - 1) >> 8;
 	UBRR0L = ((F_CPU / 16 + baud / 2) / baud - 1);
 
@@ -49,34 +48,16 @@ void beginSerial(long baud)
 
 	// enable interrupt on complete reception of a byte
 	sbi(UCSR0B, RXCIE0);
-#else
-	UBRRH = ((F_CPU / 16 + baud / 2) / baud - 1) >> 8;
-	UBRRL = ((F_CPU / 16 + baud / 2) / baud - 1);
-
-	// enable rx and tx
-	sbi(UCSRB, RXEN);
-	sbi(UCSRB, TXEN);
-
-	// enable interrupt on complete reception of a byte
-	sbi(UCSRB, RXCIE);
-#endif
 
 	// defaults to 8-bit, no parity, 1 stop bit
 }
 
 void serialWrite(unsigned char c)
 {
-#if defined(__AVR_ATmega168__)
 	while (!(UCSR0A & (1 << UDRE0)))
 		;
 
 	UDR0 = c;
-#else
-	while (!(UCSRA & (1 << UDRE)))
-		;
-
-	UDR = c;
-#endif
 }
 
 int serialAvailable()
@@ -106,18 +87,13 @@ void serialFlush()
 	rx_buffer_head = rx_buffer_tail;
 }
 
-#if defined(__AVR_ATmega168__)
-SIGNAL(SIG_USART_RECV)
+#ifdef USART_RX_vect
+SIGNAL(USART_RX_vect)
 #else
-SIGNAL(SIG_UART_RECV)
+SIGNAL(SIG_USART_RECV)
 #endif
 {
-#if defined(__AVR_ATmega168__)
 	unsigned char c = UDR0;
-#else
-	unsigned char c = UDR;
-#endif
-
 	int i = (rx_buffer_head + 1) % RX_BUFFER_SIZE;
 
 	// if we should be storing the received character into the location