Flush pending input data from device

[~andy/csm213a-hw] / vis / device.py

diff --git a/vis/device.py b/vis/device.py
index b729f02fc80ecddca1705cd3cecaa8ba3cf8a770..f1766f0f57726b6e9c9121ad70281973fbcc27fa 100644 (file)
--- a/vis/device.py
+++ b/vis/device.py
@@ -1,5 +1,6 @@
-from re     import compile
-from serial import Serial
+from re       import compile
+from serial   import Serial
+from datetime import datetime
 
 class State:
        acc   = [None]*3
@@ -7,9 +8,10 @@ class State:
        touch = [None]*2
        light = [None]*1
        a2d   = [None]*6
+       time  = None
 
        def __init__(self):
-               pass
+               self.time = datetime.utcnow()
 
 class Device:
        # Attributes
@@ -30,6 +32,7 @@ class Device:
                                bytesize = self.config.databits, \
                                stopbits = self.config.stopbits, \
                                timeout  = 0)
+                       self.serial.flushInput()
                except Exception as ex:
                        return str(ex)
 
@@ -46,12 +49,16 @@ class Device:
 
        def process(self):
                items = []
+               count = 0
+               limit = 100
+               if not self.running():
+                       return items
                while self.serial.readable():
                        try:
-                               char = self.serial.read()
+                               char = self.serial.read().decode()
                        except Exception as ex:
                                char = ''
-                       if char == '':
+                       if len(char) == 0:
                                break
                        if char == '\r' or char == '\n':
                                if len(self.inbuf) == 0:
@@ -62,6 +69,10 @@ class Device:
                                self.inbuf = []
                        else:
                                self.inbuf.append(char)
+                       if count > limit:
+                               print("Error: exceeded read limit")
+                               break
+                       count += 1
                return items
 
        # Private methods