WIP on missing bit correction & reenable read()

Author: nilscc

am2302.pxd

@@ -7,7 +7,9 @@ cdef extern from 'array':
 
 cdef extern from 'bitset':
     cdef cppclass bitset:
-        pass
+        unsigned size()
+        unsigned count()
+        bool test(unsigned)
 
 cdef extern from 'wiringPi.h':
     void wiringPiSetup()
@@ -16,12 +18,14 @@ cdef extern from 'am2302_py.hpp':
 
     cdef cppclass StreamReader:
         int pin
+        bitset bits
+
         void run()
+        void fillBits()
+
         void print()
         bool valid()
-        bool correct()
 
-        bitset bits()
         uint16_t temperature(const bitset &)
         uint16_t humidity(const bitset &)
         uint8_t parity(const bitset &)
@@ -30,5 +34,5 @@ cdef extern from 'am2302_py.hpp':
         array timingsHigh
         array timingsLow
 
-        int defectHigh()
-        int defectLow()
+        bitset missingBits()
+        bool tryCorrect()

am2302.pyx

@@ -21,27 +21,41 @@ cdef class Stream:
     def __init__(self, pin):
         self.reader.pin = pin
 
+    # Poll sensor and read data
+
     def run(self):
         self.reader.run()
 
+    #
+    # Debug output
+    #
+
     def print(self):
         self.reader.print()
 
+    #
+    # Get results
+    #
+
+    @property
     def valid(self):
         return self.reader.valid()
 
-    def correct(self):
-        return self.reader.correct()
-
+    @property
     def humidity(self):
-        return float(self.reader.humidity(self.reader.bits())) / 10.0
+        return float(self.reader.humidity(self.reader.bits)) / 10.0
 
+    @property
     def temperature(self):
-        t = self.reader.temperature(self.reader.bits())
+        t = self.reader.temperature(self.reader.bits)
         if t & 0x8000:
             t = (~t + 1) | 0x8000
         return float(t) / 10.0
 
+    #
+    # Internal timing arrays
+    #
+    
     def timingsStart(self, i, val=None):
         if val is None:
             return self.reader.timingsStart[i]
@@ -60,12 +74,40 @@ cdef class Stream:
         else:
             self.reader.timingsLow[i] = val
 
-    def defectHigh(self):
-        i = self.reader.defectHigh()
-        if i >= 0:
-            return i
+    def fillBits(self):
+        self.reader.fillBits()
+
+    # 
+    # Error detection
+    #
+
+    def missingBits(self):
+        return self.reader.missingBits().count()
+
+    def tryCorrect(self):
+        return self.reader.tryCorrect()
+
+class Result:
+    def __init__(self, temperature, humidity):
+        self.temperature = temperature
+        self.humidity = humidity
+
+def read(pin=7, retries=10):
+
+    # make sure we're initialized
+    setup()
+
+    # load stream
+    s = Stream(pin=pin)
 
-    def defectLow(self):
-        i = self.reader.defectLow()
-        if i >= 0:
-            return i
+    m = 1 + retries # number of attempts
+    for i in range(m):
+        s.run()
+        if s.valid:
+            return Result(
+                temperature=s.temperature,
+                humidity=s.humidity,
+            )
+        # sleep and retry
+        if i < m-1:
+            time.sleep(2)