time to save, motors working nicely, XON/XOFF flow control implemented for *simple* dumping of gcode

mendel/Makefile

@@ -57,7 +57,7 @@ program: $(PROGRAM).hex
 	@sleep 0.2
 	@stty $(PROGBAUD) raw ignbrk hup < $(PROGPORT)
 	$(AVRDUDE) -cstk500v1 -b$(PROGBAUD) -p$(MCU_TARGET) -P$(PROGPORT) -C/etc/avrdude.conf -U flash:w:$^
-	stty 57600 raw ignbrk -hup -echo < $(PROGPORT)
+	stty 57600 raw ignbrk -hup -echo ixon < $(PROGPORT)
 
 clean:
 	rm -rf *.o *.elf *.lst *.map *.sym *.lss *.eep *.srec *.bin *.hex *.al *.i *.s *~

mendel/clock.h

@@ -15,4 +15,18 @@ extern volatile uint8_t	clock_flag_250ms;
 #define	CLOCK_FLAG_250MS_REPORT				2
 #define	CLOCK_FLAG_250MS_STEPTIMEOUT	4
 
+/*
+	ifclock() {}
+
+	so we can do stuff like:
+	ifclock(CLOCK_FLAG_250MS_REPORT) {
+		report();
+	}
+
+	or:
+	ifclock(CLOCK_FLAG_250MS_STEPTIMEOUT)
+		disable_steppers();
+*/
+#define	ifclock(F)	for (;clock_flag_250ms & (F);clock_flag_250ms &= ~(F))
+
 #endif	/* _CLOCK_H */

mendel/dda.c

@@ -58,7 +58,13 @@ void enqueue(TARGET *t) {
 	h++;
 	if (h == MOVEBUFFER_SIZE)
 		h = 0;
+
 	dda_create(t, &movebuffer[h]);
+
+	// if queue only has one space left, stop transmition
+	if (((h + 2) & (MOVEBUFFER_SIZE - 1)) == mb_tail)
+		xoff();
+
 	mb_head = h;
 
 	// fire up in case we're not running yet
@@ -80,6 +86,20 @@ void next_move() {
 		dda_start(&movebuffer[t]);
 		mb_tail = t;
 	}
+	// restart transmission
+	xon();
+}
+
+void print_queue() {
+	serial_writechar('Q');
+	serwrite_uint8(mb_tail);
+	serial_writechar('/');
+	serwrite_uint8(mb_head);
+	if (queue_full())
+		serial_writechar('F');
+	if (queue_empty())
+		serial_writechar('E');
+	serial_writechar('\n');
 }
 
 /*
@@ -149,19 +169,6 @@ uint32_t abs32(int32_t v) {
 	return (uint32_t) (v);
 }
 
-
-void print_queue() {
-	serial_writechar('Q');
-	serwrite_uint8(mb_tail);
-	serial_writechar('/');
-	serwrite_uint8(mb_head);
-	if (queue_full())
-		serial_writechar('F');
-	if (queue_empty())
-		serial_writechar('E');
-	serial_writechar('\n');
-}
-
 /*
 	CREATE
 */
@@ -207,6 +214,9 @@ void dda_create(TARGET *target, DDA *dda) {
 		dda->nullmove = 1;
 	}
 	else {
+		// get steppers ready to go
+		steptimeout = 0;
+		enable_steppers();
 
 		if (DEBUG) {
 			serwrite_uint32(dda->total_steps); serial_writechar(',');
@@ -269,10 +279,6 @@ void dda_create(TARGET *target, DDA *dda) {
 
 	// next dda starts where we finish
 	memcpy(&startpoint, target, sizeof(TARGET));
-
-	// get steppers ready to go
-	steptimeout = 0;
-	enable_steppers();
 }
 
 /*
@@ -354,10 +360,11 @@ void dda_step(DDA *dda) {
 
 	WRITE(SCK, 0);
 
+		step_option = 0;
 	do {
 // 		WRITE(SCK, 0);
 
-		step_option = 0;
+		step_option &= ~(X_CAN_STEP | Y_CAN_STEP | Z_CAN_STEP | E_CAN_STEP | F_CAN_STEP);
 // 		step_option |= can_step(x_min(), x_max(), current_position.X, dda->endpoint.X, dda->x_direction) & X_CAN_STEP;
 // 		step_option |= can_step(y_min(), y_max(), current_position.Y, dda->endpoint.Y, dda->y_direction) & Y_CAN_STEP;
 // 		step_option |= can_step(z_min(), z_max(), current_position.Z, dda->endpoint.Z, dda->z_direction) & Z_CAN_STEP;
@@ -433,17 +440,12 @@ void dda_step(DDA *dda) {
 
 				dda->f_counter += dda->total_steps;
 
-// 				if (dda->f_scale == 0)
-// 					dda->f_scale = 1;
-
 				if (dda->f_direction) {
-// 					current_position.F += dda->f_scale;
 					current_position.F += 1;
 					if (current_position.F > dda->endpoint.F)
 						current_position.F = dda->endpoint.F;
 				}
 				else {
-// 					current_position.F -= dda->f_scale;
 					current_position.F -= 1;
 					if (current_position.F < dda->endpoint.F)
 						current_position.F = dda->endpoint.F;
@@ -457,8 +459,6 @@ void dda_step(DDA *dda) {
 			serial_writechar('[');
 			serwrite_hex8(step_option);
 			serial_writechar(':');
-// 			serwrite_uint16(dda->f_scale);
-// 			serial_writechar(',');
 			serwrite_int32(current_position.F);
 			serial_writechar('/');
 			serwrite_int32(dda->endpoint.F);
@@ -488,16 +488,16 @@ void dda_step(DDA *dda) {
 		setTimer(dda->move_duration / current_position.F);
 
 	// if we could step, we're still running
-// 	dda->live = (step_option & (X_CAN_STEP | Y_CAN_STEP | Z_CAN_STEP | E_CAN_STEP | F_CAN_STEP))?1:0;
+	dda->live = (step_option != 0)?1:0;
-	if (
+// 	if (
-			(current_position.X == dda->endpoint.X) &&
+// 			(current_position.X == dda->endpoint.X) &&
-			(current_position.Y == dda->endpoint.Y) &&
+// 			(current_position.Y == dda->endpoint.Y) &&
-			(current_position.Z == dda->endpoint.Z) &&
+// 			(current_position.Z == dda->endpoint.Z) &&
-			(current_position.E == dda->endpoint.E) &&
+// 			(current_position.E == dda->endpoint.E) &&
-			(current_position.F == dda->endpoint.F)
+// 			(current_position.F == dda->endpoint.F)
-		 ) {
+// 		 ) {
-		dda->live = 0;
+// 		dda->live = 0;
-	}
+// 	}
 
 	WRITE(SCK, 1);
 }

mendel/mendel.c

@@ -35,16 +35,21 @@ inline void io_init(void) {
 	WRITE(E_STEP_PIN, 0);	SET_OUTPUT(E_STEP_PIN);
 	WRITE(E_DIR_PIN,  0);	SET_OUTPUT(E_DIR_PIN);
 
+	// setup PWM timer: phase-correct PWM, no prescaler, no outputs enabled yet
+	TCCR0A = MASK(WGM00);
+	TCCR0B = MASK(CS00);
+	TIMSK0 = 0;
+
 	#ifdef	HEATER_PIN
-	disable_heater();
+		disable_heater();
 	#endif
 
 	#ifdef	FAN_PIN
-	disable_fan();
+		disable_fan();
 	#endif
 
 	#ifdef	STEPPER_ENABLE_PIN
-	disable_steppers();
+		disable_steppers();
 	#endif
 
 	WRITE(SCK, 1);				SET_OUTPUT(SCK);
@@ -84,7 +89,7 @@ inline void init(void) {
 
 int main (void)
 {
-	uint8_t report;
+	uint8_t report = 0;
 
 	init();
 
@@ -93,28 +98,21 @@ int main (void)
 	{
 		if (serial_rxchars()) {
 			uint8_t c = serial_popchar();
-// 			TOGGLE(SCK);
 			scan_char(c);
 		}
 
-		if (clock_flag_250ms & CLOCK_FLAG_250MS_TEMPCHECK) {
+		ifclock(CLOCK_FLAG_250MS_TEMPCHECK) {
-			clock_flag_250ms &= ~CLOCK_FLAG_250MS_TEMPCHECK;
 			temp_tick();
 		}
 
-		if (clock_flag_250ms & CLOCK_FLAG_250MS_STEPTIMEOUT) {
+		ifclock(CLOCK_FLAG_250MS_STEPTIMEOUT) {
-			clock_flag_250ms &= ~CLOCK_FLAG_250MS_STEPTIMEOUT;
+			if (steptimeout > (30 * 4))
-
-			if (steptimeout > 25) {
 				disable_steppers();
-			}
+			else
-			else {
 				steptimeout++;
-			}
 		}
 
-		if (clock_flag_250ms & CLOCK_FLAG_250MS_REPORT) {
+		ifclock(CLOCK_FLAG_250MS_REPORT) {
-			clock_flag_250ms &= ~CLOCK_FLAG_250MS_REPORT;
 			report++;
 			if (report == 4) {
 				report = 0;

mendel/pinout.h

@@ -51,6 +51,7 @@
 #define	HEATER_PIN_PWM			OC0A
 
 // #define	FAN_PIN							DIO5
+// #define	FAN_PIN_PWM					OC0B
 
 /*
 	X Stepper
@@ -106,8 +107,13 @@
 	Heater
 */
 
-#define	enable_heater()			WRITE(HEATER_PIN, 1)
+#ifdef	HEATER_PIN_PWM
-#define	disable_heater()		do { WRITE(HEATER_PIN, 0); SET_OUTPUT(HEATER_PIN); } while (0)
+	#define	enable_heater()			WRITE(HEATER_PIN, 1)
+	#define	disable_heater()		do { WRITE(HEATER_PIN, 0); } while (0)
+#else
+	#define	enable_heater()			do { TCCR0A = (TCCR0A & MASK(COM0A0)) | MASK(COM0A1); SET_OUTPUT(HEATER_PIN);  } while (0)
+	#define	disable_heater()		do { WRITE(HEATER_PIN, 0); HEATER_PIN_PWM = 0; TCCR0A &= ~(MASK(COM0A0) | MASK(COM0A1)); SET_OUTPUT(HEATER_PIN); } while (0)
+#endif
 
 /*
 	fan

mendel/serial.c

@@ -6,9 +6,18 @@
 #define		BUFSIZE		64 + sizeof(ringbuffer)
 #define		BAUD		57600
 
+#define		ASCII_XOFF	19
+#define		ASCII_XON		17
+
 volatile uint8_t _rx_buffer[BUFSIZE];
 volatile uint8_t _tx_buffer[BUFSIZE];
 
+volatile uint8_t flowflags = 0;
+#define		FLOWFLAG_SEND_XOFF	1
+#define		FLOWFLAG_SEND_XON		2
+#define		FLOWFLAG_SENT_XOFF	4
+#define		FLOWFLAG_SENT_XON		8
+
 #define	rx_buffer	((ringbuffer *) _rx_buffer)
 #define	tx_buffer	((ringbuffer *) _tx_buffer)
 
@@ -33,7 +42,15 @@ ISR(USART_RX_vect)
 
 ISR(USART_UDRE_vect)
 {
-	if (ringbuffer_canread(tx_buffer))
+	if (flowflags & FLOWFLAG_SEND_XOFF) {
+		UDR0 = ASCII_XOFF;
+		flowflags = (flowflags & ~FLOWFLAG_SEND_XOFF) | FLOWFLAG_SENT_XOFF;
+	}
+	else if (flowflags & FLOWFLAG_SEND_XON) {
+		UDR0 = ASCII_XON;
+		flowflags = (flowflags & ~FLOWFLAG_SEND_XON) | FLOWFLAG_SENT_XON;
+	}
+	else if (ringbuffer_canread(tx_buffer))
 		UDR0 = ringbuffer_readchar(tx_buffer);
 	else
 		UCSR0B &= ~(1 << UDRIE0);
@@ -103,3 +120,16 @@ void serial_writestr_P(PGM_P data)
 	for (uint8_t r; (r = pgm_read_byte(&data[i])); i++)
 		serial_writechar(r);
 }
+
+void xoff() {
+	flowflags = FLOWFLAG_SEND_XOFF;
+	// enable TX interrupt so we can send this character
+	UCSR0B |= (1 << UDRIE0);
+}
+
+void xon() {
+	if (flowflags & FLOWFLAG_SENT_XOFF)
+		flowflags = FLOWFLAG_SEND_XON;
+	// enable TX interrupt so we can send this character
+	UCSR0B |= (1 << UDRIE0);
+}

mendel/serial.h

@@ -21,4 +21,7 @@ void serial_writeblock_P(PGM_P data, int datalen);
 
 void serial_writestr_P(PGM_P data);
 
+void xoff(void);
+void xon(void);
+
 #endif	/* _SERIAL_H */