rpi_temperature: New module to monitor RPi temperature (#3587)

Module to monitor RPi cpu temperature

Signed-off-by: Al Crate <aleph@al3ph.org>

klippy/extras/rpi_temperature.py

@@ -0,0 +1,88 @@
+# Support for Raspberry Pi temperature sensor
+#
+# Copyright (C) 2020  Al Crate <al3ph@users.noreply.github.com>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+
+import logging
+
+RPI_REPORT_TIME = 1.0
+KELVIN_TO_CELSIUS = -273.15
+PROC_TEMP_FILE = "/sys/class/thermal/thermal_zone0/temp"
+
+class RPiTemperature:
+    def __init__(self, config):
+        self.printer = config.get_printer()
+        self.reactor = self.printer.get_reactor()
+        self.name = config.get_name().split()[-1]
+
+        self.temp = 0.0
+        self.file_handle = None
+
+        self.min_temp = config.getfloat('min_temp', -40,
+                                        minval=KELVIN_TO_CELSIUS)
+        self.max_temp = config.getfloat('max_temp', 85,
+                                        above=self.min_temp)
+
+        self.printer.add_object("rpi_temperature " + self.name, self)
+        self.sample_timer = self.reactor.register_timer(
+            self._sample_pi_temperature
+        )
+        try:
+            self.file_handle = open(PROC_TEMP_FILE, "r")
+        except:
+            raise config.error(
+                "Unable to open temperature file '%s'" % (PROC_TEMP_FILE)
+            )
+
+        self.printer.register_event_handler(
+            "klippy:connect", self.handle_connect
+        )
+
+
+    def handle_connect(self):
+        self.reactor.update_timer(self.sample_timer, self.reactor.NOW)
+
+
+    def setup_minmax(self, min_temp, max_temp):
+        pass
+
+    def setup_callback(self, cb):
+        self._callback = cb
+
+    def _sample_pi_temperature(self, eventtime):
+        try:
+            self.file_handle.seek(0)
+            self.temp = float(self.file_handle.read())/1000.0
+        except Exception:
+            logging.exception("rpi_temperature: Error reading data")
+            self.temp = 0.0
+            return self.reactor.NEVER
+
+        if self.temp < self.min_temp:
+            self.printer.invoke_shutdown(
+                "RPi temperature %0.1f below minimum"
+                " temperature of %0.1f." % (self.temp, self.min_temp,)
+            )
+        if self.temp > self.max_temp:
+            self.printer.invoke_shutdown(
+                "RPi temperature %0.1f above maximum"
+                " temperature of %0.1f." % (self.temp, self.max_temp,)
+            )
+
+        measured_time = self.reactor.monotonic()
+        self._callback(measured_time, self.temp)
+        return measured_time + RPI_REPORT_TIME
+
+    def get_status(self, eventtime):
+        return {
+            'temperature': self.temp,
+        }
+
+
+def load_config(config):
+    # Register sensor
+    pheaters = config.get_printer().load_object(config, "heaters")
+    pheaters.add_sensor_factory(
+        "rpi_temperature", RPiTemperature
+    )