Mattroberts' Firmware
Revision as of 14:23, 19 May 2011 by Sebastien Bailard (talk | contribs)
Release status: Beta
| Description | Firmware
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Introduction
This page will describe my firmware. At the moment it just contains my acceleration / extruder code. The license for this code sample is CC-by-3.0. The extruder pressure code is in red. The acceleration code is in green.
Config.h
// X and Y are direct drive... // 16 * 200 steps per revolution, 10 teeth, 5.08mm per tooth // 16 * 200 / 10 / 5.08 = 62.992126 steps per mm #define STEPS_PER_MM_X 62.992126 #define STEPS_PER_MM_Y 62.992126 // Z is geared... // drive gear: 16 * 200 steps per revolution, 10 teeth // driven gear: 25 teeth, 1.25 mm per revolution (M8 pitch) // 16 * 200 / 10 * 25 / 1.25 = 6400 steps per mm #define STEPS_PER_MM_Z 6400 // E... #define STEPS_PER_CUBIC_MM_E 180 #define INIT_EXTRUSION_AREA (0.465 * 0.31) // extruder advance constant (s2/mm3) // // advance (steps) = STEPS_PER_CUBIC_MM_E * EXTUDER_ADVANCE_K * cubic mm per second ^ 2 // // hooke's law says: force = k * distance // bernoulli's priniciple says: v ^ 2 / 2 + g . h + pressure / density = constant // so: v ^ 2 is proportional to number of steps we advance the extruder #define EXTRUDER_ADVANCE_K 0.019 // feedrates (mm/min) #define INIT_FEEDRATE_MM 4000 #define HOME_FEEDRATE_MM_XY 4000 #define HOME_FEEDRATE_MM_Z 150 #define MIN_FEEDRATE_MM 30 // acceleration (mm/min/s) #define ACCELERATION 150000L // steppers to disable after every move #define AUTO_DISABLE_X 0 #define AUTO_DISABLE_Y 0 #define AUTO_DISABLE_Z 1 #define AUTO_DISABLE_E 0 // stepper directions #define INVERT_X 1 #define INVERT_Y 1 #define INVERT_Z 0 #define INVERT_E 0 // minimum stepper pulse widths (us) #define STEP_HIGH_US 1 #define STEP_LOW_US 1 // thermistor // +ve --- R2 -+- THERMISTOR -+- gnd // | | // adc --------+----- R1 -----+ #define THERMISTOR_R0_OHMS 100000 #define THERMISTOR_T0_DEG_C 25 #define THERMISTOR_BETA 4036 #define THERMISTOR_R1_OHMS 0 // 0 means missing #define THERMISTOR_R2_OHMS 4500 // comms #define UART_BAUD 115200
dda.c
#include <stdint.h>
#include "config.h"
#include "convert.h"
#include "dda.h"
#include "delay.h"
#include "dist.h"
#include "motor.h"
#include "state.h"
#include "uart.h"
#ifdef DEBUG
#undef DEBUG
#define DEBUG(...) __VA_ARGS__
#else
#define DEBUG(...)
#endif
#define q_n 32 // must be a power of 2
#define STATE_IDLE 2
#define STATE_IDLE_SPEEDCHANGE 0
#define STATE_SPEEDCHANGE 1
#define STATE_DDA 3
#define STATE_XYZ 4
#define STATE_E 5
#define STATE_T 6
static struct dda {
int32_t delta[5], d, f, max_xyze;
} q[q_n];
static uint8_t q_h, q_t;
static int32_t steps_left = -1;
DEBUG(static int32_t count[5];)
static int32_t current_f, step_decel;
static int32_t max(int32_t a, int32_t b) {
return a > b ? a : b;
}
void dda_q(int32_t *fxyze) {
int32_t d;
while (q_h == q_t && steps_left != -1)
dda_tick();
DEBUG(uart_puts("dda_q");
FOREACH_XYZE(i) {
uart_puts(" "); uart_puti(fxyze[i]);
}
uart_puts(" f"); uart_putd(fxyze[F]);
uart_putc('\n');)
if (fxyze[X] == 0 && fxyze[Y] == 0 && fxyze[Z] == 0) {
if (fxyze[E] == 0 || fxyze[E] == UNSEEN)
return;
d = convert(fxyze[E], INV_E);
if (d < 0)
d = -d;
} else {
d = dist_steps(fxyze);
if (fxyze[E] == UNSEEN)
fxyze[E] = convert(d, E);
}
dda_tick();
q[q_t].d = 293L * d;
q[q_t].f = fxyze[F];
FOREACH_XYZE(i) {
q[q_t].delta[i] = fxyze[i];
s.fxyze[i] += fxyze[i];
}
DEBUG(uart_puts("d"); uart_putd(d);
uart_puts(" e"); uart_puti(fxyze[E]);
uart_puts("\n");)
q_t = (q_t + 1) & (q_n - 1);
}
void dda_tick(void) {
static int8_t state = STATE_IDLE;
static int32_t delta[5], error[5], d, max_xyzet, max_xyze, max_f, e, advance, old_advance, extrusion_rate;
switch(state++) {
case STATE_IDLE:
case STATE_IDLE_SPEEDCHANGE:
if (q_h == q_t && steps_left == -1) {
state = STATE_IDLE;
return;
}
if (steps_left == 0) {
delay_tick(0);
DEBUG(uart_puts("dda_done");
FOREACH_XYZE(i) {
uart_puts(" ");
uart_puti(count[i]);
count[i] = 0;
}
uart_puts(" ");
uart_puti(count[T]);
count[T] = 0;
uart_puts("\n");)
if (AUTO_DISABLE_X) motor_enable(X, 0);
if (AUTO_DISABLE_Y) motor_enable(Y, 0);
if (AUTO_DISABLE_Z) motor_enable(Z, 0);
if (AUTO_DISABLE_E) motor_enable(E, 0);
steps_left = -1;
q_h = (q_h + 1) & (q_n - 1);
if (q_h == q_t) {
state = STATE_IDLE;
return;
}
}
if (steps_left == -1) {
delay_tick(0);
FOREACH_TXYZE(i) {
delta[i] = q[q_h].delta[i];
error[i] = 0;
}
max_f = q[q_h].f;
d = q[q_h].d;
max_xyzet = 0;
max_xyze = 0;
steps_left = 0;
FOREACH_XYZE(i) {
motor_dir(i, delta[i] >= 0);
if (delta[i] < 0)
delta[i] = -delta[i];
if (delta[i] != 0)
motor_enable(i, 1);
steps_left += delta[i];
if (max_xyze < delta[i])
max_xyze = delta[i];
}
motor_dir(E, 1);
step_decel = steps_left / 2;
current_f = MIN_FEEDRATE_MM * 10000L;
state = STATE_SPEEDCHANGE;
}
return;
case STATE_SPEEDCHANGE:
state = STATE_DDA;
delta[T] = d / (current_f >> 11);
{
int32_t a = max_xyzet;
max_xyzet = max(max_xyze, delta[T]);
a -= max_xyzet;
a /= 2;
FOREACH_TXYZE(i)
error[i] += a;
}
return;
case STATE_DDA:
FOREACH_TXYZE(a)
error[a] += delta[a];
return;
case STATE_XYZ:
FOREACH_XYZ(a)
if (error[a] > 0) {
error[a] -= max_xyzet;
DEBUG(count[a]++);
motor_step(a);
steps_left--;
}
return;
case STATE_E:
e = 0;
if (error[E] > 0) {
error[E] -= max_xyzet;
DEBUG(count[E]++);
e++;
steps_left--;
}
extrusion_rate = current_f / 600000L;
extrusion_rate *= s.extrusion_area;
if (delta[E])
advance = (int32_t)(STEPS_PER_CUBIC_MM_E * EXTRUDER_ADVANCE_K) * extrusion_rate * extrusion_rate / 10000L;
else
advance = 0;
e += advance - old_advance;
old_advance = advance;
if (e != 0) {
if (e < 0) {
motor_dir(E, 0);
e = -e;
}
while (e-- > 0) {
motor_step(E);
motor_step_done();
}
motor_dir(E, 1);
}
motor_step_done();
return;
case STATE_T:
state = STATE_IDLE;
if (error[T] > 0) {
error[T] -= max_xyzet;
DEBUG(count[T]++);
delay_tick(1);
if (steps_left < step_decel) {
if (current_f > MIN_FEEDRATE_MM * 10000L) {
current_f -= ACCELERATION;
if (current_f < MIN_FEEDRATE_MM * 10000L)
current_f = MIN_FEEDRATE_MM * 10000L;
state = STATE_IDLE_SPEEDCHANGE;
}
} else if (current_f < max_f) {
current_f += ACCELERATION;
if (current_f >= max_f) {
current_f = max_f;
step_decel = step_decel * 2 - steps_left;
}
state = STATE_IDLE_SPEEDCHANGE;
}
}
return;
}
}
void dda_drain(void) {
while (steps_left != -1)
dda_tick();
}
