Added MLX90640 infrared camera plugin

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "platypush/backend/http/static/flag-icons"]
 	path = platypush/backend/http/static/flag-icons
 	url = https://github.com/BlackLight/flag-icon-css.git
+[submodule "platypush/plugins/gpio/sensor/ir/mlx90640/lib"]
+	path = platypush/plugins/camera/ir/mlx90640/lib
+	url = https://github.com/pimoroni/mlx90640-library

platypush/plugins/camera/ir/mlx90640/__init__.py

@@ -0,0 +1,86 @@
+import os
+import subprocess
+import time
+
+from platypush.plugins import Plugin, action
+
+
+class CameraIrMlx90640Plugin(Plugin):
+    """
+    Plugin to interact with a `ML90640 <https://shop.pimoroni.com/products/mlx90640-thermal-camera-breakout>`_
+    infrared thermal camera.
+
+    In order to use this plugin you'll need to download and compile the
+    `mlx90640 <https://github.com/pimoroni/mlx90640-library>`_ C++ bindings and examples for the device.
+    Instructions on Raspbian::
+
+        # Install the dependencies
+        $ [sudo] apt-get install libi2c-dev
+        $ cd $PLATYPUSH_SRC_DIR
+        $ git submodule init
+        $ git submodule update
+        $ cd platypush/plugins/camera/ir/mlx90640/lib
+        $ make clean
+        $ make bcm2835
+        $ make examples/rawrgb I2C_MODE=LINUX
+
+    """
+
+    _img_size = (24, 32)
+
+    def __init__(self, fps=16, skip_frames=2, scale_factor=10, rawrgb_path=None, **kwargs):
+        """
+        :param fps: Frames per seconds (default: 16)
+        :param skip_frames: Number of frames to be skipped on sensor initialization/warmup (default: 2)
+        :param scale_factor: The camera outputs 24x32 pixels artifacts. Use scale_factor to scale them up to a larger image (default: 10)
+        :param rawrgb_path: Specify it if the rawrgb executable compiled from
+            https://github.com/pimoroni/mlx90640-library is in another folder than
+            `<directory of this file>/lib/examples`.
+        """
+        super().__init__(**kwargs)
+
+        if not rawrgb_path:
+            rawrgb_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'lib', 'examples', 'rawrgb')
+
+        assert fps > 0
+        assert skip_frames >= 0
+        assert os.path.isfile(rawrgb_path)
+
+        self.fps = fps
+        self.skip_frames = skip_frames
+        self.scale_factor = scale_factor
+        self.rawrgb_path = rawrgb_path
+
+    @action
+    def capture(self, frames=1, skip_frames=None):
+        """
+        Capture one or multiple frames and return them as raw RGB
+
+        :param frames: Number of frames to be captured (default: 1)
+        :param skip_frames: If set it overrides the skip_frames parameter specified on the object (default: None)
+        """
+
+        if skip_frames is None:
+            skip_frames = self.skip_frames
+
+        input_size = self._img_size[0] * self._img_size[1] * 3
+        sleep_time = 1.0 / self.fps
+        captured_frames = []
+
+        with subprocess.Popen([self.rawrgb_path, '{}'.format(self.fps)], stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+                              stderr=subprocess.PIPE) as camera:
+            while len(captured_frames) < frames:
+                frame = camera.stdout.read(input_size)
+                size = len(frame)
+
+                if skip_frames > 0:
+                    time.sleep(sleep_time)
+                    skip_frames -= 1
+                    continue
+
+                captured_frames.append(frame)
+
+        return frames
+
+
+# vim:sw=4:ts=4:et:

platypush/plugins/camera/ir/mlx90640/lib

@@ -0,0 +1 @@
+Subproject commit f4549dc6cc416f8db05a8bfd1d4850aee5e7af75