if ((move_state.x_steps) && !endstop_stop) {
  move_state.x_counter -= dda->x_delta;
  if (move_state.x_counter < 0) {
    x_step();

if (move_state.x_steps) {
  move_state.x_counter -= dda->x_delta;
  if (move_state.x_counter < 0) {
    if ( ! endstop_stop)
      x_step();

Quote

checkbox in Skeinforge?

Quote

I try to implement it myself and add a patch.

G1 X68.03565 Y79.74415 Z-0.20 F200
G0 Z1.
G0 X72.98066 Y75.02701

...
		z_disable();
	}

	cli();

	#ifdef ACCELERATION_RAMPING
...

Quote
My config

/***************************************************************************\
* *
* 1. MECHANICAL/HARDWARE *
* *
\***************************************************************************/

/*
Set your microcontroller type in Makefile! atmega168/atmega328p/atmega644p/atmega1280

If you want to port this to a new chip, start off with arduino.h and see how you go.
*/
#if ! ( defined (__AVR_ATmega644P__) || defined (__AVR_ATmega644PA__) )
#error Sanguinololu has a 644P/644PA! set your cpu type in Makefile!
#endif

/** \def F_CPU
CPU clock rate
*/
#ifndef F_CPU
#define F_CPU 16000000L
#endif

/** \def HOST
This is the motherboard, as opposed to the extruder. See extruder/ directory for GEN3 extruder firmware
*/
#define HOST

/*
Values reflecting the gearing of your machine.
All numbers are fixed point integers, so no more than 3 digits to the right of the decimal point, please :-)
*/

/// calculate these values appropriate for your machine
/// for threaded rods, this is (steps motor per turn) / (pitch of the thread)
/// for belts, this is (steps per motor turn) / (number of gear teeth) / (belt module)
#define MICROSTEPPING_X 16.0
#define MICROSTEPPING_Y 16.0
#define MICROSTEPPING_Z 16.0
#define MICROSTEPPING_E 16.0

#define STEPS_PER_MM_X (3.401*MICROSTEPPING_X)
#define STEPS_PER_MM_Y (3.401*MICROSTEPPING_Y)
#define STEPS_PER_MM_Z (328.000*MICROSTEPPING_Z)

/// [blog.arcol.hu] may help with this one
#define STEPS_PER_MM_E (48.636*MICROSTEPPING_E)


/*
Values depending on the capabilities of your stepper motors and other mechanics.
All numbers are integers, no decimals allowed.

Units are mm/min
*/

/// used for G0 rapid moves and as a cap for all other feedrates
#define MAXIMUM_FEEDRATE_X 11000
#define MAXIMUM_FEEDRATE_Y 11000
#define MAXIMUM_FEEDRATE_Z 2000
#define MAXIMUM_FEEDRATE_E 2000

/// used when searching endstops and as default feedrate
#define SEARCH_FEEDRATE_X 2400
#define SEARCH_FEEDRATE_Y 2400
#define SEARCH_FEEDRATE_Z 1000
// no SEARCH_FEEDRATE_E, as E can't be searched

/** \def SLOW_HOMING
wether to search the home point slowly
With some endstop configurations, like when probing for the surface of a PCB, you can't deal with overrunning the endstop. In such a case, uncomment this definition.
*/
// #define SLOW_HOMING

/// this is how many steps to suck back the filament by when we stop. set to zero to disable
#define E_STARTSTOP_STEPS 0


/**
Soft axis limits, in mm.
Define them to your machine's size relative to what your host considers to be the origin.
*/

#define X_MIN -106
#define X_MAX 106

#define Y_MIN -132
#define Y_MAX 132

#define Z_MIN 0.0
#define Z_MAX 110

/** \def E_ABSOLUTE
Some G-Code creators produce relative length commands for the extruder, others absolute ones. G-Code using absolute lengths can be recognized when there are G92 E0 commands from time to time. If you have G92 E0 in your G-Code, define this flag.
*/
// #define E_ABSOLUTE



/***************************************************************************\
* *
* 2. ACCELERATION *
* *
* IMPORTANT: choose only one! These algorithms choose when to step, trying *
* to use more than one will have undefined and probably *
* disastrous results! *
* *
\***************************************************************************/

/** \def ACCELERATION_REPRAP
acceleration, reprap style.
Each movement starts at the speed of the previous command and accelerates or decelerates linearly to reach target speed at the end of the movement.
*/
// #define ACCELERATION_REPRAP

/** \def ACCELERATION_RAMPING
acceleration and deceleration ramping.
Each movement starts at (almost) no speed, linearly accelerates to target speed and decelerates just in time to smoothly stop at the target. alternative to ACCELERATION_REPRAP
*/
#define ACCELERATION_RAMPING

/** \def ACCELERATION
how fast to accelerate when using ACCELERATION_RAMPING.
given in mm/s^2, decimal allowed, useful range 1. to 10'000. Start with 10. for milling (high precision) or 1000. for printing
*/
#define ACCELERATION 1500.

/** \def ACCELERATION_TEMPORAL
temporal step algorithm
This algorithm causes the timer to fire when any axis needs to step, instead of synchronising to the axis with the most steps ala bresenham.

This algorithm is not a type of acceleration, and I haven't worked out how to integrate acceleration with it.
However it does control step timing, so acceleration algorithms seemed appropriate

The Bresenham algorithm is great for drawing lines, but not so good for steppers - In the case where X steps 3 times to Y's two, Y experiences massive jitter as it steps in sync with X every 2 out of 3 X steps. This is a worst-case, but the problem exists for most non-45/90 degree moves. At higher speeds, the jitter /will/ cause position loss and unnecessary vibration.
This algorithm instead calculates when a step occurs on any axis, and sets the timer to that value.

// TODO: figure out how to add acceleration to this algorithm
*/
// #define ACCELERATION_TEMPORAL



/***************************************************************************\
* *
* 3. PINOUTS *
* *
\***************************************************************************/

/*
Machine Pin Definitions
- make sure to avoid duplicate usage of a pin
- comment out pins not in use, as this drops the corresponding code and makes operations faster
*/

#include "arduino.h"

/** \def USE_INTERNAL_PULLUPS
internal pullup resistors
the ATmega has internal pullup resistors on it's input pins which are counterproductive with the commonly used eletronic endstops, so they should be switched off. For other endstops, like mechanical ones, you may want to uncomment this.
*/
//#define USE_INTERNAL_PULLUPS

/*
user defined pins
adjust to suit your electronics,
or adjust your electronics to suit this
*/

#define X_STEP_PIN DIO15
#define X_DIR_PIN DIO21
#define X_MIN_PIN DIO18
//#define X_MAX_PIN xxxx
//#define X_ENABLE_PIN xxxx
#define X_INVERT_DIR
//#define X_INVERT_MIN
//#define X_INVERT_MAX
//#define X_INVERT_ENABLE

#define Y_STEP_PIN DIO22
#define Y_DIR_PIN DIO23
#define Y_MIN_PIN DIO19
//#define Y_MAX_PIN xxxx
//#define Y_ENABLE_PIN xxxx
#define Y_INVERT_DIR
//#define Y_INVERT_MIN
//#define Y_INVERT_MAX
//#define Y_INVERT_ENABLE

#define Z_STEP_PIN DIO3
#define Z_DIR_PIN DIO2
#define Z_MIN_PIN DIO20
//#define Z_MAX_PIN xxxx
#define Z_ENABLE_PIN DIO26
//#define Z_INVERT_DIR
//#define Z_INVERT_MIN
//#define Z_INVERT_MAX
//#define Z_INVERT_ENABLE

#define E_STEP_PIN DIO1
#define E_DIR_PIN DIO0
//#define E_ENABLE_PIN xxxx
//#define E_INVERT_DIR

#define PS_ON_PIN DIO9
#define STEPPER_ENABLE_PIN DIO4
//#define STEPPER_INVERT_ENABLE

//#define SD_CARD_DETECT DIO2
//#define SD_WRITE_PROTECT DIO3


/***************************************************************************\
* *
* 4. TEMPERATURE SENSORS *
* *
\***************************************************************************/

/**
TEMP_HYSTERESIS: actual temperature must be target +/- hysteresis before target temperature can be achieved.
Unit is degree Celsius.
*/
#define TEMP_HYSTERESIS 5
/**
TEMP_RESIDENCY_TIME: actual temperature must be close to target for this long before target is achieved

temperature is "achieved" for purposes of M109 and friends when actual temperature is within [hysteresis] of target for [residency] seconds
*/
#define TEMP_RESIDENCY_TIME 0.1

/// which temperature sensors are you using? List every type of sensor you use here once, to enable the appropriate code. Intercom is the gen3-style separate extruder board.
// #define TEMP_MAX6675
#define TEMP_THERMISTOR
// #define TEMP_AD595
// #define TEMP_PT100
// #define TEMP_INTERCOM
// #define TEMP_NONE

/***************************************************************************\
* *
* Define your temperature sensors here *
* *
* for GEN3 set temp_type to TT_INTERCOM and temp_pin to 0 *
* *
* Types are same as TEMP_ list above- TT_MAX6675, TT_THERMISTOR, TT_AD595, *
* TT_PT100, TT_INTERCOM, TT_NONE. See list in temp.c. *
* *
\***************************************************************************/

#ifndef DEFINE_TEMP_SENSOR
#define DEFINE_TEMP_SENSOR(...)
#endif

// name type pin additional
DEFINE_TEMP_SENSOR(extruder, TT_THERMISTOR, AIO7_PIN, THERMISTOR_EXTRUDER)
//DEFINE_TEMP_SENSOR(bed, TT_THERMISTOR, AIO6_PIN, THERMISTOR_EXTRUDER)
// "noheater" is a special name for a sensor which doesn't have a heater.
// Use "M105 P#" to read it, where # is a zero-based index into this list.
// DEFINE_TEMP_SENSOR(noheater, TT_THERMISTOR, 1, 0)



/***************************************************************************\
* *
* 5. HEATERS *
* *
\***************************************************************************/

/** \def HEATER_SANITY_CHECK
check if heater responds to changes in target temperature, disable and spit errors if not
largely untested, please comment in forum if this works, or doesn't work for you!
*/
// #define HEATER_SANITY_CHECK

/***************************************************************************\
* *
* Define your heaters here *
* *
* If your heater isn't on a PWM-able pin, set heater_pwm to zero and we'll *
* use bang-bang output. Note that PID will still be used *
* *
* See Appendix 8 at the end of this file for PWMable pin mappings *
* *
* If a heater isn't attached to a temperature sensor above, it can still be *
* controlled by host but otherwise is ignored by firmware *
* *
* To attach a heater to a temp sensor above, simply use exactly the same *
* name - copy+paste is your friend *
* *
* Some common names are 'extruder', 'bed', 'fan', 'motor' *
* *
* A milling spindle can also be defined as a heater. Attach it to a *
* temperature sensor of TT_NONE, then you can control the spindle's rpm *
* via temperature commands. M104 S1..255 for spindle on, M104 S0 for off. *
* *
\***************************************************************************/

#ifndef DEFINE_HEATER
#define DEFINE_HEATER(...)
#endif

// name port pin pwm
DEFINE_HEATER(extruder, PD5)
//DEFINE_HEATER(bed, PD6)
// DEFINE_HEATER(fan, PORTB, PINB4, OCR0
// DEFINE_HEATER(chamber, PORTD, PIND7, OCR2A)
// DEFINE_HEATER(motor, PORTD, PIND6, OCR2

/// and now because the c preprocessor isn't as smart as it could be,
/// uncomment the ones you've listed above and comment the rest.
/// NOTE: these are used to enable various capability-specific chunks of code, you do NOT need to create new entries unless you are adding new capabilities elsewhere in the code!
/// so if you list a bed above, uncomment HEATER_BED, but if you list a chamber you do NOT need to create HEATED_CHAMBER
/// I have searched high and low for a way to make the preprocessor do this for us, but so far I have not found a way.

#define HEATER_EXTRUDER HEATER_extruder
//#define HEATER_BED HEATER_bed
// #define HEATER_FAN HEATER_fan



/***************************************************************************\
* *
* 6. COMMUNICATION OPTIONS *
* *
\***************************************************************************/

/** \def REPRAP_HOST_COMPATIBILITY
RepRap Host changes it's communications protocol from time to time and intentionally avoids backwards compatibility. Set this to the date the source code of your Host was fetched from RepRap's repository, which is likely also the build date.
See the discussion on the reprap-dev mailing list from 11 Oct. 2010.

Undefine it for best human readability, set it to an old date for compatibility with hosts before August 2010
*/
// #define REPRAP_HOST_COMPATIBILITY 19750101
// #define REPRAP_HOST_COMPATIBILITY 20100806
// #define REPRAP_HOST_COMPATIBILITY 20110509
// #define REPRAP_HOST_COMPATIBILITY

/**
Baud rate for the connection to the host. Usually 115200, other common values are 19200, 38400 or 57600.
*/
#define BAUD 115200

/** \def XONXOFF
Xon/Xoff flow control.
Redundant when using RepRap Host for sending GCode, but mandatory when sending GCode files with a plain terminal emulator, like GtkTerm (Linux), CoolTerm (Mac) or HyperTerminal (Windows).
Can also be set in Makefile
*/
#define XONXOFF



/***************************************************************************\
* *
* 7. MISCELLANEOUS OPTIONS *
* *
\***************************************************************************/

/** \def DEBUG
DEBUG
enables /heaps/ of extra output, and some extra M-codes.
WARNING: this WILL break most host-side talkers that expect particular responses from firmware such as reprap host and replicatorG
use with serial terminal or other suitable talker only.
*/
// #define DEBUG

/** \def BANG_BANG
BANG_BANG
drops PID loop from heater control, reduces code size significantly (1300 bytes!)
may allow DEBUG on '168
*/
#define BANG_BANG
/** \def BANG_BANG_ON
BANG_BANG_ON
PWM value for 'on'
*/
#define BANG_BANG_ON 210
/** \def BANG_BANG_OFF
BANG_BANG_OFF
PWM value for 'off'
*/
#define BANG_BANG_OFF 5

/**
move buffer size, in number of moves
note that each move takes a fair chunk of ram (69 bytes as of this writing) so don't make the buffer too big - a bigger serial readbuffer may help more than increasing this unless your gcodes are more than 70 characters long on average.
however, a larger movebuffer will probably help with lots of short consecutive moves, as each move takes a bunch of math (hence time) to set up so a longer buffer allows more of the math to be done during preceding longer moves
*/
#define MOVEBUFFER_SIZE 8

/** \def DC_EXTRUDER
DC extruder
If you have a DC motor extruder, configure it as a "heater" above and define this value as the index or name. You probably also want to comment out E_STEP_PIN and E_DIR_PIN in the Pinouts section above.
*/
// #define DC_EXTRUDER HEATER_motor
// #define DC_EXTRUDER_PWM 180

/** \def USE_WATCHDOG
Teacup implements a watchdog, which has to be reset every 250ms or it will reboot the controller. As rebooting (and letting the GCode sending application trying to continue the build with a then different Home point) is probably even worse than just hanging, and there is no better restore code in place, this is disabled for now.
*/
// #define USE_WATCHDOG

/**
analog subsystem stuff
REFERENCE - which analog reference to use. see analog.h for choices
*/
#define REFERENCE REFERENCE_AVCC

/** \def STEP_INTERRUPT_INTERRUPTIBLE
this option makes the step interrupt interruptible (nested).
this should help immensely with dropped serial characters, but may also make debugging infuriating due to the complexities arising from nested interrupts
\note disable this option if you're using a '168 or for some reason your ram usage is above 90%. This option hugely increases likelihood of stack smashing.
*/
#define STEP_INTERRUPT_INTERRUPTIBLE 1

/**
temperature history count. This is how many temperature readings to keep in order to calculate derivative in PID loop
higher values make PID derivative term more stable at the expense of reaction time
*/
#define TH_COUNT 8

/// this is the scaling of internally stored PID values. 1024L is a good value
#define PID_SCALE 1024L

/** \def ENDSTOP_STEPS
number of steps to run into the endstops intentionally
As Endstops trigger false alarm sometimes, Teacup debounces them by counting a number of consecutive positives. Valid range is 1...255. Use 4 or less for reliable endstops, 8 or even more for flaky ones.
*/
#define ENDSTOP_STEPS 4

enqueue_home(t, 0x1, 1);

enqueue_home(&t, 0x1, 1);

	#if defined Z_MIN_PIN
		home_z_negative();
	#elif defined	Z_MAX_PIN
		home_z_positive();
	#endif