extruder: Support a minimum extrude temperature

Allow the config file to specify the minimum temperature for the
extruder and check for that temperature prior to moving the extruder
motor.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/klippy/heater.py b/klippy/heater.py
index c66b251e..3797b917 100644
--- a/klippy/heater.py
+++ b/klippy/heater.py
@@ -28,6 +28,8 @@ class PrinterHeater:
         self.mcu_pwm = self.mcu_adc = None
         self.thermistor_c = Thermistors.get(config.get('thermistor_type'))
         self.pullup_r = config.getfloat('pullup_resistor', 4700.)
+        self.min_extrude_temp = config.getfloat('min_extrude_temp', 170.)
+        self.can_extrude = False
         self.lock = threading.Lock()
         self.last_temp = 0.
         self.last_temp_time = 0.
@@ -49,6 +51,8 @@ class PrinterHeater:
         control_algo = self.config.get('control', 'watermark')
         algos = {'watermark': ControlBangBang, 'pid': ControlPID}
         self.control = algos[control_algo](self, self.config)
+        if self.printer.mcu.output_file_mode:
+            self.can_extrude = True
     def run(self):
         self.mcu_adc.query_analog_in(REPORT_TIME)
     def set_pwm(self, read_time, value):
@@ -87,12 +91,16 @@ class PrinterHeater:
         with self.lock:
             self.last_temp = temp
             self.last_temp_time = read_time
+            self.can_extrude = (self.last_temp >= self.min_extrude_temp
+                                and self.target_temp >= self.min_extrude_temp)
             self.control.adc_callback(read_time, temp)
         #logging.debug("temp: %.3f %f = %f" % (read_time, read_value, temp))
     # External commands
     def set_temp(self, print_time, degrees):
         with self.lock:
             self.target_temp = degrees
+            if self.target_temp < self.min_extrude_temp:
+                self.can_extrude = False
     def get_temp(self):
         with self.lock:
             return self.last_temp, self.target_temp