gpio setup and methods to control document camera light

screenless/bureau/photography/photography.py

@@ -1,6 +1,8 @@
 import subprocess
 import tempfile
 
+from pyA20.gpio import gpio, port
+
 from bureau import Bureau, add_api
 
 
@@ -13,19 +15,35 @@ class Photography(Bureau):
     name = "Photography Dept."
     prefix = "PX"
     version = 0
+    doc_light_pin = port.PG0
 
     def __init__(self):
         Bureau.__init__(self)
         
+        # set up the gpios for lamp & knobs
+        gpio.init()
+        gpio.pullup(doc_light_pin, 0)  # reset pullup state
+        gpio.pullup(doc_light_pin, gpio.PULLDOWN)
+
+
+    def _doc_light_on(self):
+        gpio.output(self.doc_light_pin, gpio.HIGH)
+
+    def _doc_light_off(self):
+        gpio.output(self.doc_light_pin, gpio.LOW)
+
     @add_api("photo", "Get Document Photo")
     def photo(self):
         """
         Takes a photograph using the document camera.  Returns
         the file name.
         """
+        self._doc_light_on()
         tmpimg = tempfile.NamedTemporaryFile(suffix=".jpg", delete=False)
         tmpimg.close()
 
+        # TODO: make more reliable
+        # TODO: make resolution config variable
         # this is a dirty hack to keep the webcam system calls from hanging
         #cmd1 = "fswebcam --jpeg 95 --no-banner --resolution 320x240 /dev/null"
         #cmd2 = "fswebcam --jpeg 95 --no-banner --resolution 1920x1080 "
@@ -34,6 +52,7 @@ class Photography(Bureau):
         cmd2 = "uvccapture -d/dev/video1 -D2 -m -x3264 -y2448 -o" + tmpimg.name
         #subprocess.check_output(cmd1.split())
         subprocess.check_output(cmd2.split())
+        self._doc_light_off()
         return {"photo": tmpimg.name}