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Teacup_Firmware/temp.c

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#include "temp.h"
/** \file
\brief Manage temperature sensors
\note All temperatures are stored as 14.2 fixed point in Teacup, so we have
a range of 0 - 16383.75 deg Celsius at a precision of 0.25 deg. That includes
the thermistor table, which is why you can't copy and paste one from other
firmwares which don't do this.
*/
#include <stdlib.h>
#include "arduino.h"
#include "serial.h"
#include "debug.h"
#ifndef EXTRUDER
#include "sersendf.h"
#endif
#include "heater.h"
#include "simulator.h"
#ifdef TEMP_INTERCOM
#ifdef __ARMEL__
#error TEMP_INTERCOM not yet supported on ARM.
#endif
#include "intercom.h"
#include "pinio.h"
#endif
#ifdef TEMP_MAX6675
#ifdef __ARMEL__
#error MAX6675 sensors (TEMP_MAX6675) not yet supported on ARM.
#endif
#include "spi.h"
#endif
#ifdef TEMP_MCP3008
#ifdef __ARMEL__
#error MCP3008 sensors (TEMP_MCP3008) not yet supported on ARM.
#endif
#include "spi.h"
#include "thermistortable.h"
#endif
#ifdef TEMP_THERMISTOR
#include "analog.h"
#include "thermistortable.h"
#endif
#ifdef TEMP_AD595
#include "analog.h"
#endif
typedef enum {
PRESENT,
TCOPEN
} temp_flags_enum;
/// holds metadata for each temperature sensor
typedef struct {
temp_type_t temp_type; ///< type of sensor
uint8_t temp_pin; ///< pin that sensor is on
heater_t heater; ///< associated heater if any
uint8_t additional; ///< additional, sensor type specifc config
} temp_sensor_definition_t;
#undef DEFINE_TEMP_SENSOR
/// help build list of sensors from entries in config.h
#ifndef SIMULATOR
#define DEFINE_TEMP_SENSOR(name, type, pin, additional) { (type), (pin ## _ADC), (HEATER_ ## name), (additional) },
#else
#define DEFINE_TEMP_SENSOR(name, type, pin, additional) { (type), (TEMP_SENSOR_ ## name), (HEATER_ ## name), (additional) },
#endif
static const temp_sensor_definition_t temp_sensors[NUM_TEMP_SENSORS] =
{
#include "config_wrapper.h"
};
#undef DEFINE_TEMP_SENSOR
/// this struct holds the runtime sensor data- read temperatures, targets, etc
struct {
temp_flags_enum temp_flags; ///< flags
uint16_t last_read_temp; ///< last received reading
uint16_t target_temp; ///< manipulate attached heater to attempt to achieve this value
uint16_t temp_residency; ///< how long have we been close to target temperature in temp ticks?
uint16_t next_read_time; ///< how long until we can read this sensor again?
} temp_sensors_runtime[NUM_TEMP_SENSORS];
/// Set up temp sensors.
void temp_init() {
temp_sensor_t i;
for (i = 0; i < NUM_TEMP_SENSORS; i++) {
switch(temp_sensors[i].temp_type) {
#ifdef TEMP_MAX6675
case TT_MAX6675:
// Note that MAX6675's Chip Select pin is currently hardcoded to SS.
// This isn't neccessary. See also spi.h.
spi_deselect_max6675();
// Intentionally no break, we might have more than one sensor type.
#endif
#ifdef TEMP_MCP3008
case TT_MCP3008:
SET_OUTPUT(MCP3008_SELECT_PIN);
spi_deselect_mcp3008();
// Intentionally no break, we might have more than one sensor type.
#endif
#ifdef TEMP_THERMISTOR
// handled by analog_init()
/* case TT_THERMISTOR:
break;*/
#endif
#ifdef TEMP_AD595
// handled by analog_init()
/* case TT_AD595:
break;*/
#endif
#ifdef TEMP_INTERCOM
case TT_INTERCOM:
// Enable the RS485 transceiver
SET_OUTPUT(RX_ENABLE_PIN);
SET_OUTPUT(TX_ENABLE_PIN);
WRITE(RX_ENABLE_PIN,0);
disable_transmit();
intercom_init();
send_temperature(0, 0);
// Intentionally no break.
#endif
default: /* prevent compiler warning */
break;
}
}
}
/**
Read a measurement from the MCP3008 analog-digital-converter (ADC).
\param channel The ADC channel to read.
\return The raw ADC reading.
Documentation for this ADC see
https://www.adafruit.com/datasheets/MCP3008.pdf.
*/
#ifdef TEMP_MCP3008
static uint16_t mcp3008_read(uint8_t channel) {
uint8_t temp_h, temp_l;
spi_select_mcp3008();
// Start bit.
spi_rw(0x01);
// Send read address and get MSB, then LSB byte.
temp_h = spi_rw((0b1000 | channel) << 4) & 0b11;
temp_l = spi_rw(0);
spi_deselect_mcp3008();
return temp_h << 8 | temp_l;
}
#endif /* TEMP_MCP3008 */
/**
Look up a degree Celsius value from a raw ADC reading.
\param temp The raw ADC reading to look up.
\param sensor The sensor to look up. Each sensor can have its own table.
\return Degree Celsius reading in 14.2 fixed decimal format.
The table(s) looked up here are in thermistortable.h and are created on the
fly by Configtool when saving config.h. They contain value pairs mapping
raw ADC readings to 14.2 values already, so all we have to do here is to
inter-/extrapolate.
*/
#if defined TEMP_THERMISTOR || defined TEMP_MCP3008
static uint16_t temp_table_lookup(uint16_t temp, uint8_t sensor) {
uint8_t lo, hi;
uint8_t table_num = temp_sensors[sensor].additional;
// Binary search for table value bigger than our target.
//
// lo = index of highest entry less than target.
// hi = index of lowest entry greater than or equal to target.
for (lo = 0, hi = NUMTEMPS - 1; hi - lo > 1; ) {
uint8_t j = lo + (hi - lo) / 2 ;
if (pgm_read_word(&(temptable[table_num][j][0])) >= temp)
hi = j ;
else
lo = j ;
}
if (DEBUG_PID && (debug_flags & DEBUG_PID))
sersendf_P(PSTR("pin:%d Raw ADC:%d table entry: %d"),
temp_sensors[sensor].temp_pin, temp, hi);
if (sizeof(temptable[0][0]) == 2 * sizeof(uint16_t)) {
/**
This code handles temptables with value pairs and is deprecated.
It's kept for compatibility with legacy, handcrafted tables, only.
The new code expects tables with triples, nevertheless it's smaller
and also faster. Configtool was already changed to create tables
with triples, only.
*/
// Wikipedia's example linear interpolation formula.
// y = ((x - x₀)y₁ + (x₁-x)y₀) / (x₁ - x₀)
// y = temp
// x = ADC reading
// x₀= temptable[lo][0]
// x₁= temptable[hi][0]
// y₀= temptable[lo][1]
// y₁= temptable[hi][1]
temp = (
// ((x - x₀)y₁
((uint32_t)temp - pgm_read_word(&(temptable[table_num][lo][0]))) *
pgm_read_word(&(temptable[table_num][hi][1]))
// +
+
// (x₁-x)y₀)
(pgm_read_word(&(temptable[table_num][hi][0])) - (uint32_t)temp) *
pgm_read_word(&(temptable[table_num][lo][1])))
// /
/
// (x₁ - x₀)
(pgm_read_word(&(temptable[table_num][hi][0])) -
pgm_read_word(&(temptable[table_num][lo][0])));
} else
if (sizeof(temptable[0][0]) == 3 * sizeof(uint16_t)) {
// Linear interpolation using pre-computed slope.
// y = y₁ - (x - x₁) * d₁
#define X1 pgm_read_word(&(temptable[table_num][hi][0]))
#define Y1 pgm_read_word(&(temptable[table_num][hi][1]))
#define D1 pgm_read_word(&(temptable[table_num][hi][2]))
temp = Y1 - ((((int32_t)temp - X1) * D1 + (1 << 7)) >> 8);
}
if (DEBUG_PID && (debug_flags & DEBUG_PID))
sersendf_P(PSTR(" temp:%d.%d"), temp / 4, (temp % 4) * 25);
if (DEBUG_PID && (debug_flags & DEBUG_PID))
sersendf_P(PSTR(" Sensor:%d\n"), sensor);
return temp;
}
#endif /* TEMP_THERMISTOR || TEMP_MCP3008 */
/// called every 10ms from clock.c - check all temp sensors that are ready for checking
void temp_sensor_tick() {
temp_sensor_t i = 0;
for (; i < NUM_TEMP_SENSORS; i++) {
if (temp_sensors_runtime[i].next_read_time) {
temp_sensors_runtime[i].next_read_time--;
}
else {
uint16_t temp = 0;
//time to deal with this temp sensor
switch(temp_sensors[i].temp_type) {
#ifdef TEMP_MAX6675
case TT_MAX6675:
// Note: value reading in this section was rewritten without
// testing when spi.c/.h was introduced. --Traumflug
spi_select_max6675();
// No delay required, see
// https://github.com/triffid/Teacup_Firmware/issues/22
// read MSB
temp = spi_rw(0) << 8;
// read LSB
temp |= spi_rw(0);
spi_deselect_max6675();
temp_sensors_runtime[i].temp_flags = 0;
if ((temp & 0x8002) == 0) {
// got "device id"
temp_sensors_runtime[i].temp_flags |= PRESENT;
if (temp & 4) {
// thermocouple open
temp_sensors_runtime[i].temp_flags |= TCOPEN;
}
else {
temp = temp >> 3;
}
}
// this number depends on how frequently temp_sensor_tick is called. the MAX6675 can give a reading every 0.22s, so set this to about 250ms
temp_sensors_runtime[i].next_read_time = 25;
break;
#endif /* TEMP_MAX6675 */
#ifdef TEMP_THERMISTOR
case TT_THERMISTOR:
// Read current temperature.
temp = temp_table_lookup(analog_read(i), i);
temp_sensors_runtime[i].next_read_time = 0;
break;
#endif /* TEMP_THERMISTOR */
#ifdef TEMP_MCP3008
case TT_MCP3008:
// Read current temperature.
temp = temp_table_lookup(mcp3008_read(temp_sensors[i].temp_pin), i);
// This is an SPI read so it is not as fast as on-chip ADC. A read
// every 100ms should be sufficient.
temp_sensors_runtime[i].next_read_time = 10;
break;
#endif /* TEMP_MCP3008 */
#ifdef TEMP_AD595
case TT_AD595:
temp = analog_read(i);
// convert
// >>8 instead of >>10 because internal temp is stored as 14.2 fixed point
temp = (temp * 500L) >> 8;
temp_sensors_runtime[i].next_read_time = 0;
break;
#endif /* TEMP_AD595 */
#ifdef TEMP_PT100
case TT_PT100:
#warning TODO: PT100 code
break;
#endif /* TEMP_PT100 */
#ifdef TEMP_INTERCOM
case TT_INTERCOM:
temp = read_temperature(temp_sensors[i].temp_pin);
temp_sensors_runtime[i].next_read_time = 25;
break;
#endif /* TEMP_INTERCOM */
#ifdef TEMP_DUMMY
case TT_DUMMY:
temp = temp_sensors_runtime[i].last_read_temp;
if (temp_sensors_runtime[i].target_temp > temp)
temp++;
else if (temp_sensors_runtime[i].target_temp < temp)
temp--;
temp_sensors_runtime[i].next_read_time = 0;
break;
#endif /* TEMP_DUMMY */
default: /* prevent compiler warning */
break;
}
/* Exponentially Weighted Moving Average alpha constant for smoothing
noisy sensors. Instrument Engineer's Handbook, 4th ed, Vol 2 p126
says values of 0.05 to 0.1 for TEMP_EWMA are typical. */
#ifndef TEMP_EWMA
#define TEMP_EWMA 1.0
#endif
#define EWMA_SCALE 1024L
#define EWMA_ALPHA ((long) (TEMP_EWMA * EWMA_SCALE))
temp_sensors_runtime[i].last_read_temp = (uint16_t) ((EWMA_ALPHA * temp +
(EWMA_SCALE-EWMA_ALPHA) * temp_sensors_runtime[i].last_read_temp
) / EWMA_SCALE);
}
if (labs((int16_t)(temp_sensors_runtime[i].last_read_temp - temp_sensors_runtime[i].target_temp)) < (TEMP_HYSTERESIS*4)) {
if (temp_sensors_runtime[i].temp_residency < (TEMP_RESIDENCY_TIME*120))
temp_sensors_runtime[i].temp_residency++;
}
else {
// Deal with flakey sensors which occasionally report a wrong value
// by setting residency back, but not entirely to zero.
if (temp_sensors_runtime[i].temp_residency > 10)
temp_sensors_runtime[i].temp_residency -= 10;
else
temp_sensors_runtime[i].temp_residency = 0;
}
if (temp_sensors[i].heater < NUM_HEATERS) {
heater_tick(temp_sensors[i].heater, temp_sensors[i].temp_type, temp_sensors_runtime[i].last_read_temp, temp_sensors_runtime[i].target_temp);
}
if (DEBUG_PID && (debug_flags & DEBUG_PID))
sersendf_P(PSTR("DU temp: {%d %d %d.%d}"), i,
temp_sensors_runtime[i].last_read_temp,
temp_sensors_runtime[i].last_read_temp / 4,
(temp_sensors_runtime[i].last_read_temp & 0x03) * 25);
}
if (DEBUG_PID && (debug_flags & DEBUG_PID))
sersendf_P(PSTR("\n"));
}
/**
* Report whether all temp sensors in use are reading their target
* temperatures. Used for M116 and friends.
*/
uint8_t temp_achieved() {
temp_sensor_t i;
uint8_t all_ok = 255;
for (i = 0; i < NUM_TEMP_SENSORS; i++) {
if (temp_sensors_runtime[i].target_temp > 0 &&
temp_sensors_runtime[i].temp_residency < (TEMP_RESIDENCY_TIME*100))
all_ok = 0;
}
return all_ok;
}
/// specify a target temperature
/// \param index sensor to set a target for
/// \param temperature target temperature to aim for
void temp_set(temp_sensor_t index, uint16_t temperature) {
if (index >= NUM_TEMP_SENSORS)
return;
// only reset residency if temp really changed
if (temp_sensors_runtime[index].target_temp != temperature) {
temp_sensors_runtime[index].target_temp = temperature;
temp_sensors_runtime[index].temp_residency = 0;
#ifdef TEMP_INTERCOM
if (temp_sensors[index].temp_type == TT_INTERCOM)
send_temperature(temp_sensors[index].temp_pin, temperature);
#endif
}
}
/// return most recent reading for a sensor
/// \param index sensor to read
uint16_t temp_get(temp_sensor_t index) {
if (index >= NUM_TEMP_SENSORS)
return 0;
return temp_sensors_runtime[index].last_read_temp;
}
// extruder doesn't have sersendf_P
#ifndef EXTRUDER
static void single_temp_print(temp_sensor_t index) {
uint8_t c = (temp_sensors_runtime[index].last_read_temp & 3) * 25;
sersendf_P(PSTR("%u.%u"), temp_sensors_runtime[index].last_read_temp >> 2, c);
#ifdef REPORT_TARGET_TEMPS
sersendf_P(PSTR("/"));
c = (temp_sensors_runtime[index].target_temp & 3) * 25;
sersendf_P(PSTR("%u.%u"), temp_sensors_runtime[index].target_temp >> 2, c);
#endif
}
/// send temperatures to host
/// \param index sensor value to send
void temp_print(temp_sensor_t index) {
if (index == TEMP_SENSOR_none) { // standard behaviour
#ifdef HEATER_EXTRUDER
sersendf_P(PSTR("T:"));
single_temp_print(TEMP_SENSOR_extruder);
#endif
#ifdef HEATER_BED
sersendf_P(PSTR(" B:"));
single_temp_print(TEMP_SENSOR_bed);
#endif
}
else {
if (index >= NUM_TEMP_SENSORS)
return;
sersendf_P(PSTR("T[%su]:"), index);
single_temp_print(index);
}
serial_writechar('\n');
}
#endif
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