From: W. Trevor King <wking@drexel.edu>
Date: Sat, 4 Oct 2008 22:34:58 +0000 (-0400)
Subject: Cleaned up single_dio.py
X-Git-Tag: 0.1^0
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=273508cee3c008954590f4273f0b79721b7b9ee7;p=pycomedi.git

Cleaned up single_dio.py
---

diff --git a/pycomedi/single_dio.py b/pycomedi/single_dio.py
index e3fd9c0..3a0cea8 100644
--- a/pycomedi/single_dio.py
+++ b/pycomedi/single_dio.py
@@ -8,14 +8,22 @@ generate/aquire signals at 1 second and greater timescales.
 
 import comedi as c
 
-VERSION = 0.0
+VERSION = 0.1
 
 class dioError (Exception) :
     "Digital IO error"
     pass
 
-class dio_obj :
+class DIO_port :
     def __init__(self, filename="/dev/comedi0", subdevice=2, chan=(0,1,2,3), aref=0, range=0, output=True) :
+        """inputs:
+          filename:  comedi device file for your device ("/dev/comedi0").
+          subdevice: the digital IO subdevice (2)
+          chan: an iterable of the channels you wish to control ((0,1,2,3))
+          aref: the analog reference for these channels (0)
+          range: the range for these channels (0)
+          output: whether to use the lines as output (vs input) (True)
+        """
         self.filename = filename
         self.subdev = subdevice
         self.chan = chan
@@ -33,24 +41,35 @@ class dio_obj :
         else :
             self.set_to_input()
     def set_to_output(self) :
+        "switch all the channels associated with this object to be outputs"
         for chan in self.chan :
             rc = c.comedi_dio_config(self.dev, self.subdev, chan, c.COMEDI_OUTPUT)
             if rc != 1 : # yes, comedi_dio_config returns 1 on success, -1 on failure, as of comedilib-0.8.1
                 raise dioError, 'comedi_dio_config("%s", %d, %d, %d) returned %d' % (self.filename, self.subdev, chan, c.COMEDI_OUTPUT, rc)
         self.output = True
     def set_to_input(self) :
+        "switch all the channels associated with this object to be inputs"
         for chan in self.chan :
             rc = c.comedi_dio_config(self.dev, self.subdev, chan, c.COMEDI_INPUT)
             if rc != 1 :
                 raise dioError, 'comedi_dio_config("%s", %d, %d, %d) returned %d' % (self.filename, self.subdev, chan, c.COMEDI_INPUT, rc)
         self.output = False
     def write_chan_index(self, chan_index, data) :
+        """inputs:
+          chan_index: the channel you wish to write to
+          data: the value you wish to write to that channel
+        """
         if self.output != True :
             raise dioError, "Must be an output to write"
         rc = c.comedi_data_write(self.dev, self.subdev, self.chan[chan_index], self.range, self.aref, data);
         if rc != 1 : # the number of samples written
             raise dioError, "comedi_data_write returned %d" % rc
     def read_chan_index(self, chan_index) :
+        """inputs:
+          chan_index: the channel you wish to read from
+        outputs:
+          data: the value read from that channel
+        """
         if self.output == True :
             raise dioError, "Must be an input to read"
         rc, data = c.comedi_data_read(self.dev, self.subdev, self.chan[chan_index], self.range, self.aref);
@@ -58,21 +77,37 @@ class dio_obj :
             raise dioError, "comedi_data_read returned %d" % rc
         return data
     def write_port(self, data) :
-        "Channel significance increases with array index"
+        """inputs:
+          data: decimal number representing data to write
+        For example, setting data=6 will write
+          0 to chan[0]
+          1 to chan[1]
+          1 to chan[2]
+          0 to higher channels...
+        """
         for i in range(len(self.chan)) :
             self.write_chan_index(i, (data >> i) % 2)
     def read_port(self) :
+        """outputs:
+          data: decimal number representing data read
+        For example, data=6 represents
+          0 on chan[0]
+          1 on chan[1]
+          1 on chan[2]
+          0 on higher channels...
+        """
         data = 0
         for i in range(len(self.chan)) :
             data += self.read_chan_index(i) << i
         return data
 
-class write_dig_port (dio_obj) :
+class DO_port (DIO_port) :
+    "A simple wrapper on dio_obj to make writing easier"
     def __call__(self, data) :
         self.write_port(data)
 
-def _test_dio_obj() :
-    d = dio_obj()
+def _test_DIO_port() :
+    d = DIO_port()
     d.set_to_output()
     d.write_chan_index(0, 1)
     d.write_chan_index(0, 0)
@@ -84,15 +119,15 @@ def _test_dio_obj() :
     print "port value is %d" % data
     print "dio_obj success"
 
-def _test_write_dig_port() :
-    p = write_dig_port()
+def _test_DO_port() :
+    p = DO_port
     for data in [0, 1, 2, 3, 4, 5, 6, 7] :
         p(data)
     print "write_dig_port success"
 
 def test() :
-    _test_dio_obj()
-    _test_write_dig_port()
+    _test_DIO_port()
+    _test_DO_port()
 
 if __name__ == "__main__" :
     test()