It's alive! (cue evil cackle). still has some bugs, eg small movements with large delta F cause weirdness, queueing lots of moves end-to-end causes some to not execute but appear as complete in the queue

mendel/Makefile

@@ -32,7 +32,7 @@ F_CPU = 16000000L
 ##############################################################################
 
 ARCH = avr-
-OPTIMIZE = -Os -ffunction-sections  -finline-functions-called-once -DDEBUG=0
+OPTIMIZE = -Os -ffunction-sections  -finline-functions-called-once -DDEBUG=1
 # OPTIMIZE = -O0
 CFLAGS = -g -Wall -Wstrict-prototypes $(OPTIMIZE) -mmcu=$(MCU_TARGET) -DF_CPU=$(F_CPU) $(DEFS) -std=gnu99 -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -save-temps
 LDFLAGS = -Wl,--as-needed -Wl,--gc-sections
@@ -54,9 +54,10 @@ all: $(PROGRAM).hex $(PROGRAM).lst size
 
 program: $(PROGRAM).hex
 	stty $(PROGBAUD) raw ignbrk hup < $(PROGPORT)
+	@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 -hup -echo < $(PROGPORT)
+	stty 57600 raw ignbrk -hup -echo < $(PROGPORT)
 
 clean:
 	rm -rf *.o *.elf *.lst *.map *.sym *.lss *.eep *.srec *.bin *.hex *.al *.i *.s *~

mendel/arduino.h

@@ -26,6 +26,34 @@
 #define		SET_INPUT(IO)			_SET_INPUT(IO)
 #define		SET_OUTPUT(IO)		_SET_OUTPUT(IO)
 
+/*
+	ports and functions
+*/
+
+// UART
+#define	RXD									DIO0
+#define	TXD									DIO1
+
+// SPI
+#define	SCK									DIO13
+#define	MISO								DIO12
+#define	MOSI								DIO11
+#define	SS									DIO10
+
+// TWI (I2C)
+#define	SCL									AIO5
+#define	SDA									AIO4
+
+// timers and PWM
+#define	OC0A								DIO6
+#define	OC0B								DIO5
+#define	OC1A								DIO9
+#define	OC1B								DIO10
+#define	OC2A								DIO11
+#define	OC2B								DIO3
+
+#define	ICP1								DIO8
+
 /*
 	pins
 */

mendel/clock.c

@@ -10,6 +10,7 @@
 #include	<avr/interrupt.h>
 
 #include	"arduino.h"
+#include	"pinout.h"
 
 // global clock
 #ifdef	GLOBAL_CLOCK
@@ -38,6 +39,7 @@ void clock_setup() {
 }
 
 ISR(TIMER2_COMPA_vect) {
+// 	WRITE(SCK, 0);
 	// global clock
 #ifdef	GLOBAL_CLOCK
 	clock++;
@@ -47,6 +49,7 @@ ISR(TIMER2_COMPA_vect) {
 		clock_flag_250ms = 255;
 		clock_counter_250ms = 0;
 	}
+// 	WRITE(SCK, 1);
 }
 
 #ifdef	GLOBAL_CLOCK

mendel/clock.h

@@ -11,7 +11,8 @@ uint32_t	clock_read(void);
 
 extern volatile uint8_t	clock_flag_250ms;
 
-#define	CLOCK_FLAG_250MS_TEMPCHECK	1
+#define	CLOCK_FLAG_250MS_TEMPCHECK		1
-#define	CLOCK_FLAG_250MS_REPORT			2
+#define	CLOCK_FLAG_250MS_REPORT				2
+#define	CLOCL_FLAG_250MS_STEPTIMEOUT	4
 
 #endif	/* _CLOCK_H */

mendel/dda.c

@@ -18,6 +18,12 @@
 #define	DEBUG 0
 #endif
 
+/*
+	step timeout
+*/
+
+uint8_t	steptimeout = 0;
+
 /*
 	move queue
 */
@@ -201,6 +207,7 @@ void dda_create(TARGET *target, DDA *dda) {
 			dda->f_delta = dda->total_steps;
 		}
 		else {
+			// if we boost the number of steps here, many will only be F-steps which take no time- maybe we should calculate move_distance first?
 			dda->f_scale = 1;
 			dda->total_steps = dda->f_delta;
 		}
@@ -253,6 +260,10 @@ void dda_create(TARGET *target, DDA *dda) {
 	// not running yet, we fire up in dda_start()
 	dda->live = 0;
 
+	// get steppers ready to go
+	steptimeout = 0;
+	enable_steppers();
+
 	// fire up
 	enableTimerInterrupt();
 }
@@ -269,16 +280,18 @@ void dda_start(DDA *dda) {
 		return;
 	}
 
+	// set direction outputs
 	x_direction(dda->x_direction);
 	y_direction(dda->y_direction);
 	z_direction(dda->z_direction);
 	e_direction(dda->e_direction);
 
+	// ensure steppers are ready to go
+	steptimeout = 0;
 	enable_steppers();
 
-	dda->firstep = 1;
+	// set timeout for first step
-
+	setTimer(dda->move_duration / current_position.F);
-	dda->live = 1;
 }
 
 /*
@@ -321,9 +334,10 @@ void dda_step(DDA *dda) {
 #define	REAL_MOVE		32
 #define	F_REAL_STEP	64
 
-	WRITE(SCK, 1);
-
 	do {
+		WRITE(SCK, 0);
+
+		step_option = 0;
 // 		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;
@@ -417,7 +431,7 @@ void dda_step(DDA *dda) {
 			}
 		}
 
-		if (DEBUG) {
+		if (0 && DEBUG) {
 			serial_writechar('[');
 			serwrite_hex8(step_option);
 			serial_writechar(':');
@@ -430,20 +444,28 @@ void dda_step(DDA *dda) {
 			serwrite_uint32(dda->move_duration);
 			serial_writechar(']');
 		}
+
+		WRITE(SCK, 1);
+
 	} while (	((step_option & REAL_MOVE ) == 0)	&&
 						((step_option & F_CAN_STEP) != 0)	);
 
 	// turn off step outputs, hopefully they've been on long enough by now to register with the drivers
 	unstep();
 
-	// we have stepped in speed and now need to recalculate our delay
+	if (step_option & REAL_MOVE) {
-	if (((step_option & REAL_MOVE) && (step_option & F_REAL_STEP)) || (dda->firstep)) {
+		// we stepped, reset timeout
-		setTimer(dda->move_duration / current_position.F);
+		steptimeout = 0;
-		dda->firstep = 0;
+
+		// we have stepped in speed and now need to recalculate our delay
+		// WARNING: this is a divide in interrupt context! (which unfortunately seems unavoidable)
+		// we simply don't have the memory to precalculate this for each step,
+		// can't use a simplified process because the denominator changes rather than the numerator so the curve is non-linear
+		// and don't have a process framework to force it to be done outside interrupt context within a usable period of time
+		if (step_option & F_REAL_STEP)
+			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;
-
-	WRITE(SCK, 0);
 }

mendel/dda.h

@@ -51,6 +51,8 @@ extern DDA movebuffer[MOVEBUFFER_SIZE];
 extern TARGET startpoint;
 extern TARGET current_position;
 
+extern uint8_t	steptimeout;
+
 uint8_t queue_full(void);
 uint8_t queue_empty(void);
 void enqueue(TARGET *t);

mendel/gcode.c

@@ -45,7 +45,7 @@ int32_t	decfloat_to_int(decfloat *df, int32_t multiplicand, int32_t denominator)
 	if (df->sign)
 		r = -r;
 
-	// exponent- try to keep divides to a minimum at expense of slightly more code
+	// exponent- try to keep divides to a minimum for common (small) values at expense of slightly more code
 	while (e >= 5) {
 		r /= 100000;
 		e -= 5;
@@ -126,8 +126,8 @@ void scan_char(uint8_t c) {
 					serwrite_uint32(next_target.target.E);
 					break;
 				case 'F':
-					// just save an integer value for F, we need move distance and n_steps to convert it to a useful value, so wait until we have those to convert it
+					// just use raw integer, we need move distance and n_steps to convert it to a useful value, so wait until we have those to convert it
-					next_target.target.F = read_digit.mantissa;
+					next_target.target.F = decfloat_to_int(&read_digit, 1, 1);
 					serwrite_uint32(next_target.target.F);
 					break;
 				case 'S':

mendel/gcode.h

@@ -6,9 +6,9 @@
 #include	"dda.h"
 
 typedef struct {
-	uint16_t	sign			:1;
+	uint32_t	sign			:1;
-	uint16_t	mantissa	:11;
+	uint32_t	mantissa	:24;
-	uint16_t	exponent	:4;
+	uint32_t	exponent	:7;
 } decfloat;
 
 typedef struct {

mendel/machine.h

@@ -12,7 +12,7 @@
 	axis calculations, adjust as necessary
 */
 
-#define	X_STEPS_PER_REV						1600.0
+#define	X_STEPS_PER_REV						3200.0
 #define	Y_STEPS_PER_REV						X_STEPS_PER_REV
 // we need more speed than precision on Z, turn off microstepping
 #define	Z_STEPS_PER_REV						200.0
@@ -26,7 +26,7 @@
 // #define	XY_COG_CIRCUMFERENCE	(XY_COG_RADIUS * PI * 2)
 #define	Z_GEAR_RATIO							1.0
 
-#define	EXTRUDER_STEPS_PER_REV		3200.0
+#define	EXTRUDER_STEPS_PER_REV		E_STEPS_PER_REV
 #define	EXTRUDER_SHAFT_RADIUS			5.0
 #define	EXTRUDER_INLET_DIAMETER		3.0
 #define	EXTRUDER_NOZZLE_DIAMETER	0.8
@@ -40,10 +40,10 @@
 // does this refer to filament or extrudate? extrudate depends on layer thickness.. hm
 #define	STEPS_PER_MM_E						((uint32_t) ((EXTRUDER_STEPS_PER_REV / (EXTRUDER_SHAFT_RADIUS * PI * EXTRUDER_INLET_DIAMETER / EXTRUDER_NOZZLE_DIAMETER)) + 0.5))
 
-#define	FEEDRATE_FAST_XY					2400
+#define	FEEDRATE_FAST_XY					6000
-#define	FEEDRATE_SLOW_XY					120
+#define	FEEDRATE_SLOW_XY					300
-#define	FEEDRATE_FAST_Z						240
+#define	FEEDRATE_FAST_Z						6000
-#define	FEEDRATE_SLOW_Z						12
+#define	FEEDRATE_SLOW_Z						300
 
 #define	E_STARTSTOP_STEPS					20
 #define	FEEDRATE_FAST_E						1200

mendel/mendel.c

@@ -19,14 +19,7 @@
 #define	DEBUG 0
 #endif
 
-int main (void)
+inline void io_init(void) {
-{
-	uint8_t report;
-
-	// set up serial
-	serial_init();
-
-	// set up inputs and outputs
 	WRITE(X_STEP_PIN, 0);	SET_OUTPUT(X_STEP_PIN);
 	WRITE(X_DIR_PIN,  0);	SET_OUTPUT(X_DIR_PIN);
 	WRITE(X_MIN_PIN,  1);	SET_INPUT(X_MIN_PIN);
@@ -42,15 +35,29 @@ int main (void)
 	WRITE(E_STEP_PIN, 0);	SET_OUTPUT(E_STEP_PIN);
 	WRITE(E_DIR_PIN,  0);	SET_OUTPUT(E_DIR_PIN);
 
-	WRITE(HEATER_PIN, 0);	SET_OUTPUT(HEATER_PIN);
+	#ifdef	HEATER_PIN
-
+	disable_heater();			SET_OUTPUT(HEATER_PIN);
-	#ifdef	FAN_PIN
-	WRITE(FAN_PIN, 0); SET_OUTPUT(FAN_PIN);
 	#endif
 
-	WRITE(SCK, 0);	SET_OUTPUT(SCK);
+	#ifdef	FAN_PIN
-	WRITE(MISO, 1);	SET_INPUT(MISO);
+	disable_fan();				SET_OUTPUT(FAN_PIN);
-	WRITE(SS, 0);		SET_OUTPUT(SS);
+	#endif
+
+	#ifdef	STEPPER_ENABLE_PIN
+	disable_steppers();		SET_OUTPUT(STEPPER_ENABLE_PIN);
+	#endif
+
+	WRITE(SCK, 1);				SET_OUTPUT(SCK);
+	WRITE(MISO, 1);				SET_INPUT(MISO);
+	WRITE(SS, 0);					SET_OUTPUT(SS);
+}
+
+inline void init(void) {
+	// set up serial
+	serial_init();
+
+	// set up inputs and outputs
+	io_init();
 
 	// set up timers
 	setupTimerInterrupt();
@@ -66,6 +73,13 @@ int main (void)
 
 	// start queue
 	//enableTimerInterrupt();
+}
+
+int main (void)
+{
+	uint8_t report;
+
+	init();
 
 	// main loop
 	for (;;)
@@ -81,6 +95,17 @@ int main (void)
 			temp_tick();
 		}
 
+		if (clock_flag_250ms & CLOCK_FLAG_250MS_STEPTIMEOUT) {
+			clock_flag_250ms &= ~CLOCK_FLAG_250MS_STEPTIMEOUT;
+
+			if (steptimeout > 25) {
+				disable_steppers();
+			}
+			else {
+				steptimeout++;
+			}
+		}
+
 		if (clock_flag_250ms & CLOCK_FLAG_250MS_REPORT) {
 			clock_flag_250ms &= ~CLOCK_FLAG_250MS_REPORT;
 			report++;

mendel/pinout.h

@@ -12,8 +12,14 @@
 	we NEED these for communication
 */
 
-// RXD											DIO0
+#define	RESERVED_RXD				DIO0
-// TXD											DIO1
+#define	RESERVED_TXD				DIO1
+
+/*
+	user defined pins
+	adjust to suit your electronics,
+	or adjust your electronics to suit this
+*/
 
 #define	X_STEP_PIN					AIO0
 #define	X_DIR_PIN						AIO1
@@ -30,7 +36,10 @@
 #define	E_STEP_PIN					DIO7
 #define	E_DIR_PIN						DIO8
 
+#define	STEPPER_ENABLE_PIN	DIO9
+
 // list of PWM-able pins and corresponding timers
+// timer1 is reserved for step timing
 // OC0A											DIO6
 // OC0B											DIO5
 // OC1A											DIO9
@@ -41,12 +50,7 @@
 #define	HEATER_PIN					DIO6
 #define	HEATER_PIN_PWM			OC0A
 
-#define	FAN_PIN							DIO5
+// #define	FAN_PIN							DIO5
-
-#define	SCK									DIO13
-#define	MISO								DIO12
-#define	MOSI								DIO11
-#define	SS									DIO10
 
 /*
 	X Stepper
@@ -105,13 +109,25 @@
 #define	enable_heater()			WRITE(HEATER_PIN, 1)
 #define	disable_heater()		WRITE(HEATER_PIN, 0)
 
+/*
+	fan
+*/
+
+#ifdef	FAN_PIN
+	#define	enable_fan()				WRITE(FAN_PIN, 1)
+	#define	disable_fan()				WRITE(FAN_PIN, 0)
+#else
+	#define	enable_fan()				if (0) {}
+	#define	disable_fan()				if (0) {}
+#endif
+
 /*
 	Stepper Enable (ATX PSU pwr_good signal?)
 */
 
 #ifdef	STEPPER_ENABLE_PIN
-	#define	enable_steppers()		WRITE(STEPPER_ENABLE_PIN, 1)
+	#define	enable_steppers()		WRITE(STEPPER_ENABLE_PIN, 0)
-	#define	disable_steppers()	WRITE(STEPPER_ENABLE_PIN, 0)
+	#define	disable_steppers()	WRITE(STEPPER_ENABLE_PIN, 1)
 #else
 	#define	enable_steppers()		if (0) {}
 	#define	disable_steppers()	if (0) {}

mendel/temp.c

@@ -71,6 +71,8 @@ uint16_t temp_read() {
 
 	WRITE(SS, 0);
 
+	SPCR = 0;
+
 	return 0;
 }
 

mendel/timer.c

@@ -9,16 +9,19 @@ ISR(TIMER1_COMPA_vect) {
 	if(movebuffer[mb_tail].live) {
 		// this interrupt can be interruptible
 		// TODO: remove when not debugging
-		disableTimerInterrupt();
+// 		disableTimerInterrupt();
-		sei();
+// 		sei();
 
+// 	WRITE(SCK, 0);
 		dda_step(&(movebuffer[mb_tail]));
+// 	WRITE(SCK, 1);
 
-		cli();
+// 		cli();
-		enableTimerInterrupt();
+// 		enableTimerInterrupt();
 	}
-	else
+	else {
 		next_move();
+	}
 }
 
 void setupTimerInterrupt()