josh
/
Teacup_Firmware
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

temp.c: use free-running readings in EMWA mode. 

If we have EMWA mode turned on, then the user wants to average
several samples from the temp sensors over time. But now we read
temp sensors only 4 times per second making this averaging take
much longer.

Read the temperatures continuously -- as fast as supported by the
probe type -- if we are using weight averaging (TEMP_EMWA < 1.0).
This commit is contained in:
Phil Hord 2016-04-27 15:53:29 -04:00 committed by Markus Hitter
parent 6cf845ecda
commit 05565a0aec
1 changed files with 84 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

121
temp.c
View File

@ -94,6 +94,13 @@ static struct {
#define TEMP_EWMA 1.0
#endif
#define EWMA_SCALE 1024L
#define EWMA_ALPHA ((uint32_t)(TEMP_EWMA * EWMA_SCALE))
// If EWMA is used, continuously update analog reading for more data points.
#define TEMP_READ_CONTINUOUS (EWMA_ALPHA < EWMA_SCALE)
#define TEMP_NOT_READY 0xffff
/// Set up temp sensors.
void temp_init() {
temp_sensor_t i;
@ -251,7 +258,7 @@ static uint16_t temp_table_lookup(uint16_t temp, uint8_t sensor) {
#endif /* TEMP_THERMISTOR || TEMP_MCP3008 */
#ifdef TEMP_MAX6675
static uint16_t temp_read_max6675(temp_sensor_t i) {
static uint16_t temp_max6675_read(temp_sensor_t i) {
// Note: value reading in this section was rewritten without
// testing when spi.c/.h was introduced. --Traumflug
// Note: MAX6675 can give a reading every 0.22s
@ -275,6 +282,18 @@ static uint16_t temp_read_max6675(temp_sensor_t i) {
return temp;
}
static uint16_t temp_read_max6675(temp_sensor_t i) {
switch (temp_sensors_runtime[i].active++) {
case 1:
return temp_max6675_read(i);
case 22: // read temperature at most every 220ms
temp_sensors_runtime[i].active = 0;
break;
}
return TEMP_NOT_READY;
}
#endif /* TEMP_MAX6675 */
#ifdef TEMP_THERMISTOR
@ -283,26 +302,27 @@ static uint16_t temp_read_thermistor(temp_sensor_t i) {
case 1: // Start ADC conversion.
#ifdef NEEDS_START_ADC
start_adc();
return 0;
return TEMP_NOT_READY;
#endif
// else fall through to conversion
case 2: // Convert temperature values.
temp_sensors_runtime[i].active = 0;
return temp_table_lookup(analog_read(i), i);
case 0: // IDLE
default:
temp_sensors_runtime[i].active = 0;
return 0;
}
return TEMP_NOT_READY;
}
#endif /* TEMP_THERMISTOR */
#ifdef TEMP_MCP3008
static uint16_t temp_read_mcp3008(temp_sensor_t i) {
temp_sensors_runtime[i].active = 0;
switch (temp_sensors_runtime[i].active++) {
case 1:
return temp_table_lookup(mcp3008_read(temp_sensors[i].temp_pin), i);
case 10: // Idle for 100ms.
temp_sensors_runtime[i].active = 0;
}
return TEMP_NOT_READY;
}
#endif /* TEMP_MCP3008 */
@ -312,7 +332,7 @@ static uint16_t temp_read_ad595(temp_sensor_t i) {
case 1: // Start ADC conversion.
#ifdef NEEDS_START_ADC
start_adc();
return 0;
return TEMP_NOT_READY;
#endif
// else fall through to conversion
@ -321,34 +341,39 @@ static uint16_t temp_read_ad595(temp_sensor_t i) {
// Convert >> 8 instead of >> 10 because internal temp is stored as
// 14.2 fixed point.
return (analog_read(i) * 500L) >> 8;
case 0: // IDLE
default:
temp_sensors_runtime[i].active = 0;
return 0;
}
return TEMP_NOT_READY;
}
#endif /* TEMP_AD595 */
#ifdef TEMP_INTERCOM
static uint16_t temp_read_intercom(temp_sensor_t i) {
temp_sensors_runtime[i].active = 0;
switch (temp_sensors_runtime[i].active++) {
case 1:
return read_temperature(temp_sensors[i].temp_pin);
case 25: // Idle for 250ms.
temp_sensors_runtime[i].active = 0;
}
return TEMP_NOT_READY;
}
#endif /* TEMP_INTERCOM */
#ifdef TEMP_DUMMY
static uint16_t dummy_temp[NUM_TEMP_SENSORS];
static uint16_t temp_read_dummy(temp_sensor_t i) {
uint16_t temp = temp_sensors_runtime[i].last_read_temp;
if (temp_sensors_runtime[i].target_temp > dummy_temp[i])
dummy_temp[i]++;
else if (temp_sensors_runtime[i].target_temp < dummy_temp[i])
dummy_temp[i]--;
switch (temp_sensors_runtime[i].active++) {
case 1:
return dummy_temp[i] ;
case 5: // Idle for 50ms.
temp_sensors_runtime[i].active = 0;
if (temp_sensors_runtime[i].target_temp > temp)
temp++;
else if (temp_sensors_runtime[i].target_temp < temp)
temp--;
return temp;
}
return TEMP_NOT_READY;
}
#endif /* TEMP_DUMMY */
@ -395,6 +420,14 @@ static uint16_t read_temp_sensor(temp_sensor_t i) {
}
}
static void run_pid_loop(int i) {
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);
}
}
/**
Called every 10ms from clock.c. Check all temp sensors that are ready for
checking. When complete, update the PID loop for sensors tied to heaters.
@ -403,29 +436,30 @@ void temp_sensor_tick() {
temp_sensor_t i = 0;
for (; i < NUM_TEMP_SENSORS; i++) {
if (TEMP_READ_CONTINUOUS)
if ( ! temp_sensors_runtime[i].active)
temp_sensors_runtime[i].active = 1;
if (temp_sensors_runtime[i].active) {
uint16_t temp = read_temp_sensor(i);
// Ignore temperature value if sensor read is still active.
if (temp_sensors_runtime[i].active)
if (temp == TEMP_NOT_READY)
continue;
/* 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. */
#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);
// Handle moving average.
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);
// Finished reading this temperature probe. Update heater PID loop.
// This must only be done four times per second to keep the PID values
// sane.
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 ( ! TEMP_READ_CONTINUOUS) {
/**
In one-shot mode we only update temps when triggered by the
heater_tick for PID loops. So here we run the PID loop through a
cycle. This must only be done four times per second to keep the PID
values sane.
*/
run_pid_loop(i);
}
}
}
@ -437,10 +471,15 @@ void temp_sensor_tick() {
void temp_heater_tick() {
temp_sensor_t i;
// Signal all the temperature probes to begin reading.
for (i = 0; i < NUM_TEMP_SENSORS; i++)
if (TEMP_READ_CONTINUOUS)
run_pid_loop(i);
else {
// Signal all the temperature probes to begin reading. Each will run the
// pid loop for us when it completes.
temp_sensors_runtime[i].active = 1;
}
}
/**
Called every 1s from clock.c. Update temperature residency info.