htu21d: Support for HTI21D family sensor on I2C bus (#2803)

Signed-off-by: Lucio Tarantino <lucio.tarantino@gmail.com>

2 files changed, 239 insertions, 0 deletions

diff --git a/klippy/extras/heaters.py b/klippy/extras/heaters.py
index 29fb5d6e..cdb5c186 100644
--- a/klippy/extras/heaters.py
+++ b/klippy/extras/heaters.py
@@ -265,6 +265,7 @@ class PrinterHeaters:
         self.printer.try_load_module(config, "adc_temperature")
         self.printer.try_load_module(config, "spi_temperature")
         self.printer.try_load_module(config, "bme280")
+        self.printer.try_load_module(config, "htu21d")
         sensor_type = config.get('sensor_type')
         if sensor_type not in self.sensor_factories:
             raise self.printer.config_error(
diff --git a/klippy/extras/htu21d.py b/klippy/extras/htu21d.py
new file mode 100644
index 00000000..3c9e0590
--- /dev/null
+++ b/klippy/extras/htu21d.py
@@ -0,0 +1,238 @@
+# HTU21D(F)/Si7013/Si7020/Si7021/SHT21 i2c based temperature sensors support
+#
+# Copyright (C) 2020  Lucio Tarantino <lucio.tarantino@gmail.com>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+
+######################################################################
+# NOTE: The implementation requires write support of length 0
+#       before reading on the i2c bus of the mcu.
+#
+# Compatible Sensors:
+#       HTU21D - Tested on Linux MCU.
+#       Si7013 - Untested
+#       Si7020 - Untested
+#       Si7021 - Untested
+#       SHT21  - Untested
+#
+######################################################################
+
+import bus
+import logging
+
+HTU21D_I2C_ADDR= 0x40
+
+HTU21D_COMMANDS = {
+    'HTU21D_TEMP'       :0xE3,
+    'HTU21D_HUMID'      :0xE5,
+    'HTU21D_TEMP_NH'    :0xF3,
+    'HTU21D_HUMID_NH'   :0xF5,
+    'WRITE'             :0xE6,
+    'READ'              :0xE7,
+    'RESET'             :0xFE,
+    'SERIAL'            :[0xFA,0x0F,0xFC,0xC9],
+    'FIRMWARE_READ'     :[0x84,0xB8]
+
+}
+
+HTU21D_RESOLUTION_MASK = 0x7E;
+HTU21D_RESOLUTIONS = {
+    'TEMP14_HUM12':int('00000000',2),
+    'TEMP13_HUM10':int('10000000',2),
+    'TEMP12_HUM08':int('00000001',2),
+    'TEMP11_HUM11':int('10000001',2)
+}
+
+# Device with conversion time for tmp/resolution bit
+# The format is:
+#  <CHIPNAME>:{id:<ID>, ..<RESOlUTION>:[<temp time>,<humidity time>].. }
+HTU21D_DEVICES = {
+    'SI7013':{'id':0x0D,
+        'TEMP14_HUM12':[.11,.12],
+        'TEMP13_HUM10':[ .7, .5],
+        'TEMP12_HUM08':[ .4, .4],
+        'TEMP11_HUM11':[ .3, .7]},
+    'SI7020':{'id':0x14,
+        'TEMP14_HUM12':[.11,.12],
+        'TEMP13_HUM10':[ .7, .5],
+        'TEMP12_HUM08':[ .4, .4],
+        'TEMP11_HUM11':[ .3, .7]},
+    'SI7021':{'id':0x14,
+        'TEMP14_HUM12':[.11,.12],
+        'TEMP13_HUM10':[ .7, .5],
+        'TEMP12_HUM08':[ .4, .4],
+        'TEMP11_HUM11':[ .3, .7]},
+    'SHT21': {'id':0x31,
+        'TEMP14_HUM12':[.85,.29],
+        'TEMP13_HUM10':[.43, .9],
+        'TEMP12_HUM08':[.22, .4],
+        'TEMP11_HUM11':[.11,.15]},
+    'HTU21D':{'id':0x32,
+        'TEMP14_HUM12':[.50,.16],
+        'TEMP13_HUM10':[.25, .5],
+        'TEMP12_HUM08':[.13, .3],
+        'TEMP11_HUM11':[.12, .8]}
+}
+#temperature coefficient for RH compensation at range 0C..80C,
+#  for HTU21D & SHT21 only
+HTU21D_TEMP_COEFFICIENT= -0.15
+#crc8 polynomial for 16bit value, CRC8 -> x^8 + x^5 + x^4 + 1
+HTU21D_CRC8_POLYNOMINAL= 0x13100
+
+class HTU21D:
+    def __init__(self, config):
+        self.printer = config.get_printer()
+        self.name = config.get_name().split()[-1]
+        self.reactor = self.printer.get_reactor()
+        self.i2c = bus.MCU_I2C_from_config(
+            config, default_addr=HTU21D_I2C_ADDR, default_speed=100000)
+        self.hold_master_mode = config.getboolean('htu21d_hold_master',False)
+        self.resolution = config.get('htu21d_resolution','TEMP12_HUM08')
+        self.report_time = config.getint('htu21d_report_time',30,minval=5)
+        if self.resolution not in HTU21D_RESOLUTIONS:
+            raise config.error("Invalid HTU21D Resolution. Valid are %s"
+                % '|'.join(HTU21D_RESOLUTIONS.keys()))
+        self.deviceId = config.get('sensor_type')
+        self.temp = self.humidity = 0.
+        self.sample_timer = self.reactor.register_timer(self._sample_htu21d)
+        self.printer.add_object("htu21d " + self.name, self)
+        self.printer.register_event_handler("klippy:ready", self.handle_ready)
+
+    def handle_ready(self):
+        self._init_htu21d()
+        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 _init_htu21d(self):
+        # Device Soft Reset
+        self.i2c.i2c_write([HTU21D_COMMANDS['RESET']])
+        # Wait 15ms after reset
+        self.reactor.pause(self.reactor.monotonic() + .15)
+
+        # Read ChipId
+        params = self.i2c.i2c_read([HTU21D_COMMANDS['SERIAL'][2],
+                                    HTU21D_COMMANDS['SERIAL'][3]], 3)
+        response = bytearray(params['response'])
+        rdevId = response[0] << 8
+        rdevId |= response[1]
+        checksum = response[2]
+        if self._chekCRC8(rdevId) != checksum:
+            logging.warn("htu21d: Reading deviceId !Checksum error!")
+        rdevId = rdevId >> 8
+        deviceId_list = list(
+            filter(
+              lambda elem: HTU21D_DEVICES[elem]['id'] == rdevId,HTU21D_DEVICES)
+            )
+        if len(deviceId_list) != 0:
+            logging.info("htu21d: Found Device Type %s" % deviceId_list[0])
+        else:
+            logging.warn("htu21d: Unknown Device ID %#x " % rdevId)
+
+        if(self.deviceId != deviceId_list[0]):
+            logging.warn(
+                "htu21d: Found device %s. Forcing to type %s as config.",
+                 deviceId_list[0],self.deviceId)
+
+        # Set Resolution
+        params = self.i2c.i2c_read([HTU21D_COMMANDS['READ']], 1)
+        response = bytearray(params['response'])
+        registerData = response[0] & HTU21D_RESOLUTION_MASK
+        registerData |= HTU21D_RESOLUTIONS[self.resolution]
+        self.i2c.i2c_write([HTU21D_COMMANDS['WRITE']],registerData)
+        logging.info("htu21d: Setting resolution to %s " % self.resolution)
+
+    def _sample_htu21d(self, eventtime):
+        try:
+            # Read Temeprature
+            if self.hold_master_mode:
+                params = self.i2c.i2c_write([HTU21D_COMMANDS['HTU21D_TEMP']])
+            else:
+                params = self.i2c.i2c_write([HTU21D_COMMANDS['HTU21D_TEMP_NH']])
+
+            # Wait
+            self.reactor.pause(self.reactor.monotonic()
+            + HTU21D_DEVICES[self.deviceId][self.resolution][0])
+
+
+            params = self.i2c.i2c_read([],3)
+
+            response = bytearray(params['response'])
+            rtemp  = response[0] << 8
+            rtemp |= response[1]
+            if self._chekCRC8(rtemp) != response[2]:
+                logging.warn("htu21d: Checksum error on Temperature reading!")
+            else:
+                self.temp = (0.002681 * float(rtemp) - 46.85)
+                logging.debug("htu21d: Temperature %.2f " % self.temp)
+
+            # Read Humidity
+            if self.hold_master_mode:
+                self.i2c.i2c_write([HTU21D_COMMANDS['HTU21D_HUMID']])
+            else:
+                self.i2c.i2c_write([HTU21D_COMMANDS['HTU21D_HUMID_NH']])
+
+            # Wait
+            self.reactor.pause(self.reactor.monotonic()
+            + HTU21D_DEVICES[self.deviceId][self.resolution][1])
+
+            params = self.i2c.i2c_read([],3)
+
+            response = bytearray(params['response'])
+            rhumid = response[0] << 8
+            rhumid|= response[1]
+            if self._chekCRC8(rhumid) != response[2]:
+                logging.warn("htu21d: Checksum error on Humidity reading!")
+            else:
+                #clear status bits,
+                # humidity always returns xxxxxx10 in the LSB field
+                rhumid   ^= 0x02;
+                self.humidity = (0.001907 * float(rhumid) - 6)
+                if (self.humidity < 0):
+                    #due to RH accuracy, measured value might be
+                    # slightly less than 0 or more 100
+                    self.temp = 0
+                elif (self.humidity > 100):
+                    self.humidity = 100
+                # Only for HTU21D & SHT21.
+                # Calculates temperature compensated Humidity, %RH
+                if( self.deviceId in ['SHT21','HTU21D']
+                    and self.temp > 0 and self.temp < 80):
+                    logging.debug("htu21d: Do temp compensation..")
+                    self.humidity = self.humidity
+                    + (25.0 - self.temp) * HTU21D_TEMP_COEFFICIENT;
+                logging.debug("htu21d: Humidity %.2f " % self.humidity)
+        except Exception:
+            logging.exception("htu21d: Error reading data")
+            self.temp = self.humidity = .0
+            return self.reactor.NEVER
+
+        measured_time = self.reactor.monotonic()
+        self._callback(measured_time, self.temp)
+        return measured_time + self.report_time
+
+    def _chekCRC8(self,data):
+        for bit in range(0,16):
+            if (data & 0x8000):
+                data = (data << 1) ^ HTU21D_CRC8_POLYNOMINAL;
+            else:
+                data <<= 1
+        data = data >> 8
+        return data
+
+    def get_status(self, eventtime):
+        return {
+            'temperature': self.temp,
+            'humidity': self.humidity,
+        }
+
+
+def load_config(config):
+    # Register sensor
+    pheater = config.get_printer().lookup_object("heaters")
+    for stype in HTU21D_DEVICES:
+        pheater.add_sensor_factory(stype, HTU21D)