Better support for int types (#10409)

* Better int types support

* type

* Added optional register order

* Fix white spaces

* Fix line length

* Fix line too long

* Fix trailing whitespace

* Stylistc code fixes

homeassistant/components/sensor/modbus.py

@@ -11,7 +11,8 @@ import voluptuous as vol
 
 import homeassistant.components.modbus as modbus
 from homeassistant.const import (
-    CONF_NAME, CONF_OFFSET, CONF_UNIT_OF_MEASUREMENT, CONF_SLAVE)
+    CONF_NAME, CONF_OFFSET, CONF_UNIT_OF_MEASUREMENT, CONF_SLAVE,
+    CONF_STRUCTURE)
 from homeassistant.helpers.entity import Entity
 from homeassistant.helpers import config_validation as cv
 from homeassistant.components.sensor import PLATFORM_SCHEMA
@@ -21,6 +22,7 @@ _LOGGER = logging.getLogger(__name__)
 DEPENDENCIES = ['modbus']
 
 CONF_COUNT = 'count'
+CONF_REVERSE_ORDER = 'reverse_order'
 CONF_PRECISION = 'precision'
 CONF_REGISTER = 'register'
 CONF_REGISTERS = 'registers'
@@ -32,7 +34,9 @@ REGISTER_TYPE_HOLDING = 'holding'
 REGISTER_TYPE_INPUT = 'input'
 
 DATA_TYPE_INT = 'int'
+DATA_TYPE_UINT = 'uint'
 DATA_TYPE_FLOAT = 'float'
+DATA_TYPE_CUSTOM = 'custom'
 
 PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
     vol.Required(CONF_REGISTERS): [{
@@ -41,12 +45,15 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
         vol.Optional(CONF_REGISTER_TYPE, default=REGISTER_TYPE_HOLDING):
             vol.In([REGISTER_TYPE_HOLDING, REGISTER_TYPE_INPUT]),
         vol.Optional(CONF_COUNT, default=1): cv.positive_int,
+        vol.Optional(CONF_REVERSE_ORDER, default=False): cv.boolean,
         vol.Optional(CONF_OFFSET, default=0): vol.Coerce(float),
         vol.Optional(CONF_PRECISION, default=0): cv.positive_int,
         vol.Optional(CONF_SCALE, default=1): vol.Coerce(float),
         vol.Optional(CONF_SLAVE): cv.positive_int,
         vol.Optional(CONF_DATA_TYPE, default=DATA_TYPE_INT):
-            vol.In([DATA_TYPE_INT, DATA_TYPE_FLOAT]),
+            vol.In([DATA_TYPE_INT, DATA_TYPE_UINT, DATA_TYPE_FLOAT,
+                    DATA_TYPE_CUSTOM]),
+        vol.Optional(CONF_STRUCTURE): cv.string,
         vol.Optional(CONF_UNIT_OF_MEASUREMENT): cv.string
     }]
 })
@@ -55,7 +62,37 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
 def setup_platform(hass, config, add_devices, discovery_info=None):
     """Set up the Modbus sensors."""
     sensors = []
+    data_types = {DATA_TYPE_INT: {1: 'h', 2: 'i', 4: 'q'}}
+    data_types[DATA_TYPE_UINT] = {1: 'H', 2: 'I', 4: 'Q'}
+    data_types[DATA_TYPE_FLOAT] = {1: 'e', 2: 'f', 4: 'd'}
+
     for register in config.get(CONF_REGISTERS):
+        structure = '>i'
+        if register.get(CONF_DATA_TYPE) != DATA_TYPE_CUSTOM:
+            try:
+                structure = '>{:c}'.format(data_types[
+                    register.get(CONF_DATA_TYPE)][register.get(CONF_COUNT)])
+            except KeyError:
+                _LOGGER.error("Unable to detect data type for %s sensor, "
+                              "try a custom type.", register.get(CONF_NAME))
+                continue
+        else:
+            structure = register.get(CONF_STRUCTURE)
+
+        try:
+            size = struct.calcsize(structure)
+        except struct.error as err:
+            _LOGGER.error(
+                "Error in sensor %s structure: %s",
+                register.get(CONF_NAME), err)
+            continue
+
+        if register.get(CONF_COUNT) * 2 != size:
+            _LOGGER.error(
+                "Structure size (%d bytes) mismatch registers count "
+                "(%d words)", size, register.get(CONF_COUNT))
+            continue
+
         sensors.append(ModbusRegisterSensor(
             register.get(CONF_NAME),
             register.get(CONF_SLAVE),
@@ -63,10 +100,14 @@ def setup_platform(hass, config, add_devices, discovery_info=None):
             register.get(CONF_REGISTER_TYPE),
             register.get(CONF_UNIT_OF_MEASUREMENT),
             register.get(CONF_COUNT),
+            register.get(CONF_REVERSE_ORDER),
             register.get(CONF_SCALE),
             register.get(CONF_OFFSET),
-            register.get(CONF_DATA_TYPE),
+            structure,
             register.get(CONF_PRECISION)))
+
+    if not sensors:
+        return False
     add_devices(sensors)
 
 
@@ -74,8 +115,8 @@ class ModbusRegisterSensor(Entity):
     """Modbus register sensor."""
 
     def __init__(self, name, slave, register, register_type,
-                 unit_of_measurement, count, scale, offset, data_type,
+                 unit_of_measurement, count, reverse_order, scale, offset,
-                 precision):
+                 structure, precision):
         """Initialize the modbus register sensor."""
         self._name = name
         self._slave = int(slave) if slave else None
@@ -83,10 +124,11 @@ class ModbusRegisterSensor(Entity):
         self._register_type = register_type
         self._unit_of_measurement = unit_of_measurement
         self._count = int(count)
+        self._reverse_order = reverse_order
         self._scale = scale
         self._offset = offset
         self._precision = precision
-        self._data_type = data_type
+        self._structure = structure
         self._value = None
 
     @property
@@ -120,17 +162,15 @@ class ModbusRegisterSensor(Entity):
 
         try:
             registers = result.registers
+            if self._reverse_order:
+                registers.reverse()
         except AttributeError:
             _LOGGER.error("No response from modbus slave %s register %s",
                           self._slave, self._register)
             return
-        if self._data_type == DATA_TYPE_FLOAT:
         byte_string = b''.join(
             [x.to_bytes(2, byteorder='big') for x in registers]
         )
-            val = struct.unpack(">f", byte_string)[0]
+        val = struct.unpack(self._structure, byte_string)[0]
-        elif self._data_type == DATA_TYPE_INT:
-            for i, res in enumerate(registers):
-                val += res * (2**(i*16))
         self._value = format(
             self._scale * val + self._offset, '.{}f'.format(self._precision))