cleaned up serial completing support for non blocking tx and refactoring formatting functions into a new module 'print'

Makefile

@@ -31,7 +31,7 @@ DEVICE     = atmega328p
 CLOCK      = 16000000
 PROGRAMMER = -c avrisp2 -P usb
 OBJECTS    = main.o motion_control.o gcode.o spindle_control.o serial.o protocol.o stepper.o \
-             eeprom.o settings.o planner.o nuts_bolts.o limits.o
+             eeprom.o settings.o planner.o nuts_bolts.o limits.o print.o
 # FUSES      = -U hfuse:w:0xd9:m -U lfuse:w:0x24:m
 FUSES      = -U hfuse:w:0xd2:m -U lfuse:w:0xff:m
 # update that line with this when programmer is back up: 

doc/resources.txt

@@ -3,7 +3,7 @@ Allocation of AVR peripherals in Grbl
 
 See config.h for pin allocation.
 
-The UART is handled by 'wiring_serial' and used primarily for streaming gcode
+The UART is handled by 'serial' and used primarily for streaming gcode
 
 16 bit Timer 1 and the TIMER1_COMPA interrupt is used by the 'stepper' module to handle step events
 

doc/structure.txt

@@ -37,3 +37,5 @@ Supporting files:
 'nuts_bolts.h'    : A tiny collection of useful constants and macros used everywhere
 
 'serial'          : Low level serial communications
+
+'print'           : Functions to print strings of different formats (using serial)

main.c

@@ -22,6 +22,7 @@
 #include <avr/sleep.h>
 #include <avr/interrupt.h>
 #include <util/delay.h>
+#include "config.h"
 #include "planner.h"
 #include "stepper.h"
 #include "spindle_control.h"
@@ -33,12 +34,9 @@
 #include "settings.h"
 #include "serial.h"
 
-// #ifndef __AVR_ATmega328P__
-// #  error "As of version 0.6 Grbl only supports atmega328p. If you want to run Grbl on an 168 check out 0.51 ('git co v0_51')"
-// #endif
-
 int main(void)
 {
+  serial_init(BAUD_RATE);
   protocol_init();        
   settings_init();  
   plan_init();      

motion_control.c

@@ -27,7 +27,6 @@
 #include "nuts_bolts.h"
 #include "stepper.h"
 #include "planner.h"
-#include "serial.h"
 
 
 void mc_dwell(uint32_t milliseconds) 

planner.c

@@ -29,7 +29,6 @@
 #include "stepper.h"
 #include "settings.h"
 #include "config.h"
-#include "serial.h"
 
 // The number of linear motions that can be in the plan at any give time
 #ifdef __AVR_ATmega328P__

print.c

@@ -0,0 +1,58 @@
+#include <math.h>
+#include <avr/pgmspace.h>
+#include "serial.h"
+
+void printString(const char *s)
+{
+	while (*s)
+		serial_write(*s++);
+}
+
+// Print a string stored in PGM-memory
+void printPgmString(const char *s)
+{
+  char c;
+	while ((c = pgm_read_byte_near(s++)))
+		serial_write(c);
+}
+
+void printIntegerInBase(unsigned long n, unsigned long base)
+{ 
+	unsigned char buf[8 * sizeof(long)]; // Assumes 8-bit chars. 
+	unsigned long i = 0;
+
+	if (n == 0) {
+		serial_write('0');
+		return;
+	} 
+
+	while (n > 0) {
+		buf[i++] = n % base;
+		n /= base;
+	}
+
+	for (; i > 0; i--)
+		serial_write(buf[i - 1] < 10 ?
+			'0' + buf[i - 1] :
+			'A' + buf[i - 1] - 10);
+}
+
+void printInteger(long n)
+{
+	if (n < 0) {
+		serial_write('-');
+		n = -n;
+	}
+
+	printIntegerInBase(n, 10);
+}
+
+void printFloat(double n)
+{
+  double integer_part, fractional_part;
+  fractional_part = modf(n, &integer_part);
+  printInteger(integer_part);
+  serial_write('.');
+  printInteger(round(fractional_part*1000));
+}
+

print.h

@@ -0,0 +1,14 @@
+#ifndef print_h
+#define print_h
+
+void printNewline(void);
+void printString(const char *s);
+void printPgmString(const char *s);
+void printInteger(long n);
+void printHex(unsigned long n);
+void printOctal(unsigned long n);
+void printBinary(unsigned long n);
+void printIntegerInBase(unsigned long n, unsigned long base);
+void printFloat(double n);
+
+#endif

protocol.c

@@ -22,6 +22,7 @@
 #include "protocol.h"
 #include "gcode.h"
 #include "serial.h"
+#include "print.h"
 #include "settings.h"
 #include "config.h"
 #include <math.h>
@@ -55,7 +56,6 @@ static void status_message(int status_code) {
 
 void protocol_init() 
 {
-  beginSerial(BAUD_RATE);  
   printPgmString(PSTR("\r\nGrbl " GRBL_VERSION));
   printPgmString(PSTR("\r\n"));  
 }
@@ -72,7 +72,7 @@ uint8_t protocol_execute_line(char *line) {
 void protocol_process()
 {
   char c;
-  while((c = serialRead()) != -1) 
+  while((c = serial_read()) != 0xff) 
   {
     if((char_counter > 0) && ((c == '\n') || (c == '\r'))) {  // Line is complete. Then execute!
       line[char_counter] = 0; // treminate string

serial.c

@@ -21,9 +21,8 @@
 
 */
 
-#include <math.h>
-#include <avr/pgmspace.h>
 #include <avr/interrupt.h>
+#include <avr/sleep.h>
 
 // Define constants and variables for buffering incoming serial data.  We're
 // using a ring buffer (I think), in which rx_buffer_head is the index of the
@@ -46,7 +45,7 @@ uint8_t tx_buffer_head = 0;
 volatile uint8_t tx_buffer_tail = 0;
 
 
-void beginSerial(long baud)
+void serial_init(long baud)
 {
 	UBRR0H = ((F_CPU / 16 + baud / 2) / baud - 1) >> 8;
 	UBRR0L = ((F_CPU / 16 + baud / 2) / baud - 1);
@@ -64,52 +63,46 @@ void beginSerial(long baud)
 	// defaults to 8-bit, no parity, 1 stop bit
 }
 
-void serialWrite(uint8_t data) {
+void serial_write(uint8_t data) {
+  // Calculate next head
   uint8_t next_head = (tx_buffer_head + 1) % TX_BUFFER_SIZE;
 
-  // wait until there's a space in the buffer
-  while (next_head == tx_buffer_tail) ;
+  // Wait until there's a space in the buffer
+  while (next_head == tx_buffer_tail) { sleep_mode(); };
 
+  // Store data and advance head
   tx_buffer[tx_buffer_head] = data;
   tx_buffer_head = next_head;
   
-  // enable the Data Register Empty Interrupt
+  // Enable Data Register Empty Interrupt
 	UCSR0B |=  (1 << UDRIE0); 
 }
 
-// interrupt called on Data Register Empty
+// Data Register Empty Interrupt handler
 SIGNAL(USART_UDRE_vect) {
-  // temporary tx_buffer_tail 
-  // (to optimize for volatile, there are no interrupts inside an interrupt routine)
+  
+  // temporary tx_buffer_tail (to optimize for volatile)
   uint8_t tail = tx_buffer_tail;
 
-  // get a byte from the buffer	
-  uint8_t data = tx_buffer[tail];
-  // send the byte
-  UDR0 = data;
+  // Send a byte from the buffer	
+  UDR0 = tx_buffer[tail];
 
-  // update tail position
+  // Update tail position
   tail ++;
   tail %= TX_BUFFER_SIZE;
+  tx_buffer_tail = tail;
 
-  // if the buffer is empty,  disable the interrupt
+  // Turn off Data Register Empty Interrupt if this concludes the transfer
   if (tail == tx_buffer_head) { 
     UCSR0B &= ~(1 << UDRIE0); 
   }
 
-  tx_buffer_tail = tail;
 }
 
-// Returns true if there is any data in the read buffer
-int serialAnyAvailable()
+uint8_t serial_read()
 {
-  return (rx_buffer_head != rx_buffer_tail);
-}
-
-uint8_t serialRead()
-{
-	if (!serialAnyAvailable()) {
-		return -1;
+	if (rx_buffer_head != rx_buffer_tail) {
+		return 0xff;
 	} else {
 		uint8_t data = rx_buffer[rx_buffer_tail];
 		rx_buffer_tail = (rx_buffer_tail + 1) % RX_BUFFER_SIZE;
@@ -132,62 +125,3 @@ SIGNAL(USART_RX_vect)
 	}
 }
 
-void printByte(unsigned char c)
-{
-	serialWrite((uint8_t) c);
-}
-
-void printString(const char *s)
-{
-	while (*s)
-		printByte(*s++);
-}
-
-// Print a string stored in PGM-memory
-void printPgmString(const char *s)
-{
-  char c;
-	while ((c = pgm_read_byte_near(s++)))
-		printByte(c);
-}
-
-void printIntegerInBase(unsigned long n, unsigned long base)
-{ 
-	unsigned char buf[8 * sizeof(long)]; // Assumes 8-bit chars. 
-	unsigned long i = 0;
-
-	if (n == 0) {
-		printByte('0');
-		return;
-	} 
-
-	while (n > 0) {
-		buf[i++] = n % base;
-		n /= base;
-	}
-
-	for (; i > 0; i--)
-		printByte(buf[i - 1] < 10 ?
-			'0' + buf[i - 1] :
-			'A' + buf[i - 1] - 10);
-}
-
-void printInteger(long n)
-{
-	if (n < 0) {
-		printByte('-');
-		n = -n;
-	}
-
-	printIntegerInBase(n, 10);
-}
-
-void printFloat(double n)
-{
-  double integer_part, fractional_part;
-  fractional_part = modf(n, &integer_part);
-  printInteger(integer_part);
-  printByte('.');
-  printInteger(round(fractional_part*1000));
-}
-

serial.h

@@ -25,20 +25,8 @@
 #ifndef serial_h
 #define serial_h
 
-void beginSerial(long);
-void serialWrite(uint8_t);
-int serialAnyAvailable(void);
-uint8_t serialRead(void);
-void printMode(int);
-void printByte(unsigned char c);
-void printNewline(void);
-void printString(const char *s);
-void printPgmString(const char *s);
-void printInteger(long n);
-void printHex(unsigned long n);
-void printOctal(unsigned long n);
-void printBinary(unsigned long n);
-void printIntegerInBase(unsigned long n, unsigned long base);
-void printFloat(double n);
+void serial_init(long);
+void serial_write(uint8_t);
+uint8_t serial_read(void);
 
 #endif

settings.c

@@ -23,7 +23,7 @@
 #include "nuts_bolts.h"
 #include "settings.h"
 #include "eeprom.h"
-#include "serial.h"
+#include "print.h"
 #include <avr/pgmspace.h>
 #include "protocol.h"
 #include "config.h"

stepper.c

@@ -30,7 +30,6 @@
 #include "nuts_bolts.h"
 #include <avr/interrupt.h>
 #include "planner.h"
-#include "serial.h"
 #include "limits.h"
 
 // Some useful constants