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Teacup_Firmware/heater.c

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#include "heater.h"
/** \file
\brief Manage heaters
*/
#include <stdlib.h>
#include <avr/eeprom.h>
#include <avr/pgmspace.h>
#include "arduino.h"
#include "debug.h"
#include "temp.h"
#include "pinio.h"
#include "crc.h"
#ifndef EXTRUDER
#include "sersendf.h"
#endif
/// \struct heater_definition_t
/// \brief simply holds pinout data- port, pin, pwm channel if used
typedef struct {
volatile uint8_t *heater_port; ///< pointer to port. DDR is inferred from this pointer too
uint8_t heater_pin; ///< heater pin, not masked. eg for PB3 enter '3' here, or PB3_PIN or similar
volatile uint8_t *heater_pwm; ///< pointer to 8-bit PWM register, eg OCR0A (8-bit) or ORC3L (low byte, 16-bit)
} heater_definition_t;
#undef DEFINE_HEATER
/// \brief helper macro to fill heater definition struct from config.h
#define DEFINE_HEATER(name, pin, pwm) { &(pin ## _WPORT), pin ## _PIN, \
pwm ? (pin ## _PWM) : NULL},
static const heater_definition_t heaters[NUM_HEATERS] =
{
#include "config_wrapper.h"
};
#undef DEFINE_HEATER
/**
\var heaters_pid
\brief this struct holds the heater PID factors
PID is a fascinating way to control any closed loop control, combining the error (P), cumulative error (I) and rate at which we're approacing the setpoint (D) in such a way that when correctly tuned, the system will achieve target temperature quickly and with little to no overshoot
At every sample, we calculate \f$OUT = k_P (S - T) + k_I \int (S - T) + k_D \frac{dT}{dt}\f$ where S is setpoint and T is temperature.
The three factors kP, kI, kD are chosen to give the desired behaviour given the dynamics of the system.
See http://www.embedded.com/design/prototyping-and-development/4211211/PID-without-a-PhD for the full story
*/
struct {
int32_t p_factor; ///< scaled P factor: mibicounts/qc
int32_t i_factor; ///< scaled I factor: mibicounts/(qC*qs)
int32_t d_factor; ///< scaled D factor: mibicounts/(qc/(TH_COUNT*qs))
int16_t i_limit; ///< scaled I limit, such that \f$-i_{limit} < i_{factor} < i_{limit}\f$
} heaters_pid[NUM_HEATERS];
/// \brief this struct holds the runtime heater data- PID integrator history, temperature history, sanity checker
struct {
int16_t heater_i; ///< integrator, \f$-i_{limit} < \sum{4*eC*\Delta t} < i_{limit}\f$
uint16_t temp_history[TH_COUNT]; ///< store last TH_COUNT readings in a ring, so we can smooth out our differentiator
uint8_t temp_history_pointer; ///< pointer to last entry in ring
#ifdef HEATER_SANITY_CHECK
uint16_t sanity_counter; ///< how long things haven't seemed sane
uint16_t sane_temperature; ///< a temperature we consider sane given the heater settings
#endif
uint8_t heater_output; ///< this is the PID value we eventually send to the heater
} heaters_runtime[NUM_HEATERS];
#ifdef BANG_BANG
#define HEATER_THRESHOLD ((BANG_BANG_ON + BANG_BANG_OFF) / 2)
#else
#define HEATER_THRESHOLD 8
#endif
/// default scaled P factor, equivalent to 8.0 counts/qC or 32 counts/C
#define DEFAULT_P 8192
/// default scaled I factor, equivalent to 0.5 counts/(qC*qs) or 8 counts/C*s
#define DEFAULT_I 512
/// default scaled D factor, equivalent to 24 counts/(qc/(TH_COUNT*qs)) or 192 counts/(C/s)
#define DEFAULT_D 24576
/// default scaled I limit, equivalent to 384 qC*qs, or 24 C*s
#define DEFAULT_I_LIMIT 384
#ifdef EECONFIG
/// this lives in the eeprom so we can save our PID settings for each heater
typedef struct {
int32_t EE_p_factor;
int32_t EE_i_factor;
int32_t EE_d_factor;
int16_t EE_i_limit;
uint16_t crc; ///< crc so we can use defaults if eeprom data is invalid
} EE_factor;
EE_factor EEMEM EE_factors[NUM_HEATERS];
#endif /* EECONFIG */
/// \brief initialise heater subsystem
/// Set directions, initialise PWM timers, read PID factors from eeprom, etc
void heater_init() {
heater_t i;
// setup PWM timers: fast PWM
// Warning 2012-01-11: these are not consistent across all AVRs
TCCR0A = MASK(WGM01) | MASK(WGM00);
// PWM frequencies in TCCR0B, see page 108 of the ATmega644 reference.
TCCR0B = MASK(CS00); // F_CPU / 256 (about 78(62.5) kHz on a 20(16) MHz chip)
#ifndef FAST_PWM
TCCR0B = MASK(CS00) | MASK(CS02); // F_CPU / 256 / 1024 (about 76(61) Hz)
#endif
TIMSK0 = 0;
OCR0A = 0;
OCR0B = 0;
// timer 1 is used for stepping
#ifdef TCCR2A
TCCR2A = MASK(WGM21) | MASK(WGM20);
// PWM frequencies in TCCR2B, see page 156 of the ATmega644 reference.
TCCR2B = MASK(CS20); // F_CPU / 256 (about 78(62.5) kHz on a 20(16) MHz chip)
#ifndef FAST_PWM
TCCR2B = MASK(CS20) | MASK(CS21) | MASK(CS22); // F_CPU / 256 / 1024
#endif
TIMSK2 = 0;
OCR2A = 0;
OCR2B = 0;
#endif
#ifdef TCCR3A
TCCR3A = MASK(WGM30);
TCCR3B = MASK(WGM32) | MASK(CS30);
TIMSK3 = 0;
OCR3A = 0;
OCR3B = 0;
#endif
#ifdef TCCR4A
#ifdef TIMER4_IS_10_BIT
// ATmega16/32U4 fourth timer is a special 10 bit timer
TCCR4A = MASK(PWM4A) | MASK(PWM4B) ; // enable A and B
TCCR4C = MASK(PWM4D); // and D
TCCR4D = MASK(WGM40); // Phase correct
TCCR4B = MASK(CS40); // no prescaler
#ifndef FAST_PWM
TCCR4B = MASK(CS40) | MASK(CS42) | MASK(CS43); // 16 MHz / 1024 / 256
//TCCR4B = MASK(CS40) | MASK(CS41) | MASK(CS43); // 16 MHz / 4096 / 256
#endif
TC4H = 0; // clear high bits
OCR4C = 0xff; // 8 bit max count at top before reset
#else
TCCR4A = MASK(WGM40);
TCCR4B = MASK(WGM42) | MASK(CS40);
#endif
TIMSK4 = 0;
OCR4A = 0;
OCR4B = 0;
#ifdef OCR4D
OCR4D = 0;
#endif
#endif
#ifdef TCCR5A
TCCR5A = MASK(WGM50);
TCCR5B = MASK(WGM52) | MASK(CS50);
TIMSK5 = 0;
OCR5A = 0;
OCR5B = 0;
#endif
// setup pins
for (i = 0; i < NUM_HEATERS; i++) {
if (heaters[i].heater_pwm) {
*heaters[i].heater_pwm = 0;
// this is somewhat ugly too, but switch() won't accept pointers for reasons unknown
switch((uint16_t) heaters[i].heater_pwm) {
case (uint16_t) &OCR0A:
TCCR0A |= MASK(COM0A1);
break;
case (uint16_t) &OCR0B:
TCCR0A |= MASK(COM0B1);
break;
#ifdef TCCR2A
case (uint16_t) &OCR2A:
TCCR2A |= MASK(COM2A1);
break;
case (uint16_t) &OCR2B:
TCCR2A |= MASK(COM2B1);
break;
#endif
#ifdef TCCR3A
case (uint16_t) &OCR3AL:
TCCR3A |= MASK(COM3A1);
break;
case (uint16_t) &OCR3BL:
TCCR3A |= MASK(COM3B1);
break;
#ifdef COM3C1
case (uint16_t) &OCR3CL:
TCCR3A |= MASK(COM3C1);
break;
#endif
#endif
#ifdef TCCR4A
#if defined (OCR4AL)
case (uint16_t) &OCR4AL:
TCCR4A |= MASK(COM4A1);
break;
case (uint16_t) &OCR4BL:
TCCR4A |= MASK(COM4B1);
break;
case (uint16_t) &OCR4CL:
TCCR4A |= MASK(COM4C1);
break;
#else
// 10 bit timer
case (uint16_t) &OCR4A:
TCCR4A |= MASK(COM4A1);
break;
case (uint16_t) &OCR4B:
TCCR4A |= MASK(COM4B1);
break;
#ifdef OCR4D
case (uint16_t) &OCR4D:
TCCR4C |= MASK(COM4D1);
break;
#endif
#endif
#endif
#ifdef TCCR5A
case (uint16_t) &OCR5AL:
TCCR5A |= MASK(COM5A1);
break;
case (uint16_t) &OCR5BL:
TCCR5A |= MASK(COM5B1);
break;
case (uint16_t) &OCR5CL:
TCCR5A |= MASK(COM5C1);
break;
#endif
}
}
#ifdef HEATER_SANITY_CHECK
// 0 is a "sane" temperature when we're trying to cool down
heaters_runtime[i].sane_temperature = 0;
#endif
#ifndef BANG_BANG
#ifdef EECONFIG
// read factors from eeprom
heaters_pid[i].p_factor =
eeprom_read_dword((uint32_t *) &EE_factors[i].EE_p_factor);
heaters_pid[i].i_factor =
eeprom_read_dword((uint32_t *) &EE_factors[i].EE_i_factor);
heaters_pid[i].d_factor =
eeprom_read_dword((uint32_t *) &EE_factors[i].EE_d_factor);
heaters_pid[i].i_limit =
eeprom_read_word((uint16_t *) &EE_factors[i].EE_i_limit);
if (crc_block(&heaters_pid[i].p_factor, 14) != eeprom_read_word((uint16_t *) &EE_factors[i].crc))
#endif /* EECONFIG */
{
heaters_pid[i].p_factor = DEFAULT_P;
heaters_pid[i].i_factor = DEFAULT_I;
heaters_pid[i].d_factor = DEFAULT_D;
heaters_pid[i].i_limit = DEFAULT_I_LIMIT;
}
#endif /* BANG_BANG */
}
// set all heater pins to output
do {
#undef DEFINE_HEATER
#define DEFINE_HEATER(name, pin, pwm) WRITE(pin, 0); SET_OUTPUT(pin);
#include "config_wrapper.h"
#undef DEFINE_HEATER
} while (0);
}
/** \brief run heater PID algorithm
\param h which heater we're running the loop for
\param type which temp sensor type this heater is attached to
\param current_temp the temperature that the associated temp sensor is reporting
\param target_temp the temperature we're trying to achieve
*/
void heater_tick(heater_t h, temp_type_t type, uint16_t current_temp, uint16_t target_temp) {
// Static, so it's not mandatory to calculate a new value, see BANG_BANG.
static uint8_t pid_output;
#ifndef BANG_BANG
int16_t heater_p;
int16_t heater_d;
int16_t t_error = target_temp - current_temp;
#endif /* BANG_BANG */
if (h >= NUM_HEATERS)
return;
if (target_temp == 0) {
heater_set(h, 0);
return;
}
#ifndef BANG_BANG
heaters_runtime[h].temp_history[heaters_runtime[h].temp_history_pointer++] = current_temp;
heaters_runtime[h].temp_history_pointer &= (TH_COUNT - 1);
// PID stuff
// proportional
heater_p = t_error; // Units: qC where 4qC=1C
// integral
heaters_runtime[h].heater_i += t_error; // Units: qC*qs where 16qC*qs=1C*s
// prevent integrator wind-up
if (heaters_runtime[h].heater_i > heaters_pid[h].i_limit)
heaters_runtime[h].heater_i = heaters_pid[h].i_limit;
else if (heaters_runtime[h].heater_i < -heaters_pid[h].i_limit)
heaters_runtime[h].heater_i = -heaters_pid[h].i_limit;
// derivative. Units: qC/(TH_COUNT*qs) where 1C/s=TH_COUNT*4qC/4qs=8qC/qs)
// note: D follows temp rather than error so there's no large derivative when the target changes
heater_d = heaters_runtime[h].temp_history[heaters_runtime[h].temp_history_pointer] - current_temp;
// combine factors
int32_t pid_output_intermed = ( // Units: counts
(
(((int32_t) heater_p) * heaters_pid[h].p_factor) +
(((int32_t) heaters_runtime[h].heater_i) * heaters_pid[h].i_factor) +
(((int32_t) heater_d) * heaters_pid[h].d_factor)
) / PID_SCALE
);
// rebase and limit factors
if (pid_output_intermed > 255) {
if (t_error > 0)
heaters_runtime[h].heater_i -= t_error; // un-integrate
pid_output = 255;
}
else if (pid_output_intermed < 0) {
if (t_error < 0)
heaters_runtime[h].heater_i -= t_error; // un-integrate
pid_output = 0;
}
else
pid_output = pid_output_intermed & 0xFF;
if (DEBUG_PID && (debug_flags & DEBUG_PID))
sersendf_P(PSTR("T{E:%d, P:%d * %ld = %ld / I:%d * %ld = %ld / D:%d * %ld = %ld # O: %ld = %u}\n"), t_error, heater_p, heaters_pid[h].p_factor, (int32_t) heater_p * heaters_pid[h].p_factor / PID_SCALE, heaters_runtime[h].heater_i, heaters_pid[h].i_factor, (int32_t) heaters_runtime[h].heater_i * heaters_pid[h].i_factor / PID_SCALE, heater_d, heaters_pid[h].d_factor, (int32_t) heater_d * heaters_pid[h].d_factor / PID_SCALE, pid_output_intermed, pid_output);
#else
if (current_temp >= target_temp + (TEMP_HYSTERESIS))
pid_output = BANG_BANG_OFF;
else if (current_temp <= target_temp - (TEMP_HYSTERESIS))
pid_output = BANG_BANG_ON;
// else keep pid_output
#endif
#ifdef HEATER_SANITY_CHECK
// check heater sanity
// implementation is a moving window with some slow-down to compensate for thermal mass
if (target_temp > (current_temp + (TEMP_HYSTERESIS*4))) {
// heating
if (current_temp > heaters_runtime[h].sane_temperature)
// hotter than sane- good since we're heating unless too hot
heaters_runtime[h].sane_temperature = current_temp;
else {
if (heaters_runtime[h].sanity_counter < 40)
heaters_runtime[h].sanity_counter++;
else {
heaters_runtime[h].sanity_counter = 0;
// ratchet up expected temp
heaters_runtime[h].sane_temperature++;
}
}
// limit to target, so if we overshoot by too much for too long an error is flagged
if (heaters_runtime[h].sane_temperature > target_temp)
heaters_runtime[h].sane_temperature = target_temp;
}
else if (target_temp < (current_temp - (TEMP_HYSTERESIS*4))) {
// cooling
if (current_temp < heaters_runtime[h].sane_temperature)
// cooler than sane- good since we're cooling
heaters_runtime[h].sane_temperature = current_temp;
else {
if (heaters_runtime[h].sanity_counter < 125)
heaters_runtime[h].sanity_counter++;
else {
heaters_runtime[h].sanity_counter = 0;
// ratchet down expected temp
heaters_runtime[h].sane_temperature--;
}
}
// if we're at or below 60 celsius, don't freak out if we can't drop any more.
if (current_temp <= 240)
heaters_runtime[h].sane_temperature = current_temp;
// limit to target, so if we don't cool down for too long an error is flagged
else if (heaters_runtime[h].sane_temperature < target_temp)
heaters_runtime[h].sane_temperature = target_temp;
}
// we're within HYSTERESIS of our target
else {
heaters_runtime[h].sane_temperature = current_temp;
heaters_runtime[h].sanity_counter = 0;
}
// compare where we're at to where we should be
if (labs((int16_t)(current_temp - heaters_runtime[h].sane_temperature)) > (TEMP_HYSTERESIS*4)) {
// no change, or change in wrong direction for a long time- heater is broken!
pid_output = 0;
sersendf_P(PSTR("!! heater %d or its temp sensor broken - temp is %d.%dC, target is %d.%dC, didn't reach %d.%dC in %d0 milliseconds\n"), h, current_temp >> 2, (current_temp & 3) * 25, target_temp >> 2, (target_temp & 3) * 25, heaters_runtime[h].sane_temperature >> 2, (heaters_runtime[h].sane_temperature & 3) * 25, heaters_runtime[h].sanity_counter);
}
#endif /* HEATER_SANITY_CHECK */
heater_set(h, pid_output);
}
/** \brief manually set PWM output
\param index the heater we're setting the output for
\param value the PWM value to write
anything done by this function is overwritten by heater_tick above if the heater has an associated temp sensor
*/
void heater_set(heater_t index, uint8_t value) {
if (index >= NUM_HEATERS)
return;
heaters_runtime[index].heater_output = value;
if (heaters[index].heater_pwm) {
*(heaters[index].heater_pwm) = value;
if (DEBUG_PID && (debug_flags & DEBUG_PID))
sersendf_P(PSTR("PWM{%u = %u}\n"), index, *heaters[index].heater_pwm);
}
else {
if (value >= HEATER_THRESHOLD)
*(heaters[index].heater_port) |= MASK(heaters[index].heater_pin);
else
*(heaters[index].heater_port) &= ~MASK(heaters[index].heater_pin);
}
if (value)
power_on();
}
/** \brief check wether all heaters are off
*/
uint8_t heaters_all_zero() {
uint8_t i;
for (i = 0; i < NUM_HEATERS; i++) {
if (heaters_runtime[i].heater_output)
return 0;
}
return 255;
}
/** \brief turn off all heaters
for emergency stop
*/
uint8_t heaters_all_off() {
uint8_t i;
for (i = 0; i < NUM_HEATERS; i++) {
if (heaters_runtime[i].heater_output > 0)
return 0;
}
return 255;
}
#ifdef EECONFIG
/** \brief set heater P factor
\param index heater to change factor for
\param p scaled P factor
*/
void pid_set_p(heater_t index, int32_t p) {
#ifndef BANG_BANG
if (index >= NUM_HEATERS)
return;
heaters_pid[index].p_factor = p;
#endif /* BANG_BANG */
}
/** \brief set heater I factor
\param index heater to change I factor for
\param i scaled I factor
*/
void pid_set_i(heater_t index, int32_t i) {
#ifndef BANG_BANG
if (index >= NUM_HEATERS)
return;
heaters_pid[index].i_factor = i;
#endif /* BANG_BANG */
}
/** \brief set heater D factor
\param index heater to change D factor for
\param d scaled D factor
*/
void pid_set_d(heater_t index, int32_t d) {
#ifndef BANG_BANG
if (index >= NUM_HEATERS)
return;
heaters_pid[index].d_factor = d;
#endif /* BANG_BANG */
}
/** \brief set heater I limit
\param index heater to set I limit for
\param i_limit scaled I limit
*/
void pid_set_i_limit(heater_t index, int32_t i_limit) {
#ifndef BANG_BANG
if (index >= NUM_HEATERS)
return;
heaters_pid[index].i_limit = i_limit;
#endif /* BANG_BANG */
}
/// \brief Write PID factors to eeprom
void heater_save_settings() {
#ifndef BANG_BANG
heater_t i;
for (i = 0; i < NUM_HEATERS; i++) {
eeprom_write_dword((uint32_t *) &EE_factors[i].EE_p_factor, heaters_pid[i].p_factor);
eeprom_write_dword((uint32_t *) &EE_factors[i].EE_i_factor, heaters_pid[i].i_factor);
eeprom_write_dword((uint32_t *) &EE_factors[i].EE_d_factor, heaters_pid[i].d_factor);
eeprom_write_word((uint16_t *) &EE_factors[i].EE_i_limit, heaters_pid[i].i_limit);
eeprom_write_word((uint16_t *) &EE_factors[i].crc, crc_block(&heaters_pid[i].p_factor, 14));
}
#endif /* BANG_BANG */
}
#endif /* EECONFIG */
#ifndef EXTRUDER
/** \brief send heater debug info to host
\param i index of heater to send info for
*/
void heater_print(uint16_t i) {
sersendf_P(PSTR("P:%ld I:%ld D:%ld Ilim:%u crc:%u "), heaters_pid[i].p_factor, heaters_pid[i].i_factor, heaters_pid[i].d_factor, heaters_pid[i].i_limit, crc_block(&heaters_pid[i].p_factor, 14));
}
#endif
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