Fix the exception handling

Line_Follower.py

@@ -1,101 +1,103 @@
-
-import smbus
-import math
-import time
-
-class Line_Follower(object):
-	def __init__(self, address=0x11, references=[300, 300, 300, 300, 300]):
-		self.bus = smbus.SMBus(1)
-		self.address = address
-		self._references = references
-
-	def read_raw(self):
-		for i in range(0, 5):
-			try:
-				raw_result = self.bus.read_i2c_block_data(self.address, 0, 10)
-				Connection_OK = True
-				break
-			except:
-				Connection_OK = False
-
-		if Connection_OK:
-			return raw_result
-		else:
-			return False
-			print "Error accessing %2X" % self.address
-
-	def read_analog(self):
-		raw_result = self.read_raw()
-		if raw_result:
-			analog_result = [0, 0, 0, 0, 0]
-			for i in range(0, 5):
-				high_byte = raw_result[i*2] << 8
-				low_byte = raw_result[i*2+1]
-				analog_result[i] = high_byte + low_byte
-			return analog_result
-
-	def read_digital(self):	
-		lt = self.read_analog()
-		digital_list = []
-		for i in range(0, 5):
-			if lt[i] > self._references[i]:
-				digital_list.append(0)
-			elif lt[i] < self._references[i]:
-				digital_list.append(1)
-			else:
-				digital_list.append(-1)
-		return digital_list
-
-	def get_average(self, mount):
-		if not isinstance(mount, int):
-			raise ValueError("Mount must be interger")
-		average = [0, 0, 0, 0, 0]
-		lt_list = [[], [], [], [], []]
-		for times in range(0, mount):
-			lt = self.read_analog()
-			for lt_id in range(0, 5):
-				lt_list[lt_id].append(lt[lt_id])
-		for lt_id in range(0, 5):
-			average[lt_id] = int(math.fsum(lt_list[lt_id])/mount)
-		return average
-
-	def found_line_in(self, timeout):
-		if isinstance(timeout, int) or isinstance(timeout, float):
-			pass
-		else:
-			raise ValueError("timeout must be interger or float")
-		time_start = time.time()
-		time_during = 0
-		while time_during < timeout:
-			lt_status = self.read_digital()
-			result = 0
-			if 1 in lt_status:
-				return lt_status
-			time_now = time.time()
-			time_during = time_now - time_start
-		return False
-
-	def wait_tile_status(self, status):
-		while True:
-			lt_status = self.read_digital()
-			if lt_status in status:
-				break
-
-	def wait_tile_center(self):
-		while True:
-			lt_status = self.read_digital()
-			if lt_status[2] == 1:
-				break
-
-	@property
-	def references(self):
-		return self._references
-
-	@references.setter
-	def references(self, value):
-		self._references = value
-
-if __name__ == '__main__':
-	lf = Line_Follower()
-	while True:
-		print lf.read_analog()
+
+from __future__ import print_function
+import smbus
+import math
+import time
+import logging
+
+class Line_Follower(object):
+	def __init__(self, address=0x11, references=[300, 300, 300, 300, 300]):
+		self.bus = smbus.SMBus(1)
+		self.address = address
+		self._references = references
+
+	def read_raw(self):
+		for i in range(0, 5):
+			try:
+				raw_result = self.bus.read_i2c_block_data(self.address, 0, 10)
+				Connection_OK = True
+				break
+			except IOError:
+				logging.exception('Error reading')
+				Connection_OK = False
+
+		if Connection_OK:
+			return raw_result
+		else:
+			raise RuntimeError("Error accessing %2X" % self.address)
+
+	def read_analog(self):
+		raw_result = self.read_raw()
+		if raw_result:
+			analog_result = [0, 0, 0, 0, 0]
+			for i in range(0, 5):
+				high_byte = raw_result[i*2] << 8
+				low_byte = raw_result[i*2+1]
+				analog_result[i] = high_byte + low_byte
+			return analog_result
+
+	def read_digital(self):	
+		lt = self.read_analog()
+		digital_list = []
+		for i in range(0, 5):
+			if lt[i] > self._references[i]:
+				digital_list.append(0)
+			elif lt[i] < self._references[i]:
+				digital_list.append(1)
+			else:
+				digital_list.append(-1)
+		return digital_list
+
+	def get_average(self, mount):
+		if not isinstance(mount, int):
+			raise ValueError("Mount must be interger")
+		average = [0, 0, 0, 0, 0]
+		lt_list = [[], [], [], [], []]
+		for times in range(0, mount):
+			lt = self.read_analog()
+			for lt_id in range(0, 5):
+				lt_list[lt_id].append(lt[lt_id])
+		for lt_id in range(0, 5):
+			average[lt_id] = int(math.fsum(lt_list[lt_id])/mount)
+		return average
+
+	def found_line_in(self, timeout):
+		if isinstance(timeout, int) or isinstance(timeout, float):
+			pass
+		else:
+			raise ValueError("timeout must be interger or float")
+		time_start = time.time()
+		time_during = 0
+		while time_during < timeout:
+			lt_status = self.read_digital()
+			result = 0
+			if 1 in lt_status:
+				return lt_status
+			time_now = time.time()
+			time_during = time_now - time_start
+		return False
+
+	def wait_tile_status(self, status):
+		while True:
+			lt_status = self.read_digital()
+			if lt_status in status:
+				break
+
+	def wait_tile_center(self):
+		while True:
+			lt_status = self.read_digital()
+			if lt_status[2] == 1:
+				break
+
+	@property
+	def references(self):
+		return self._references
+
+	@references.setter
+	def references(self, value):
+		self._references = value
+
+if __name__ == '__main__':
+	lf = Line_Follower()
+	while True:
+		print(lf.read_analog())

README.md

@@ -1,17 +1,18 @@
-## SunFounder UltraSonic_Avoidance
-SunFounder UltraSonic_Avoidance
+## SunFounder Line Follower
+SunFounder Line Follower
 
 Quick Links:
 
- * [About SunFounder UltraSonic_Avoidance](#about_this_module)
+ * [About SunFounder Line Follower](#about_this_module)
  * [Update](#update)
  * [About SunFounder](#about_sunfounder)
  * [License](#license)
  * [Contact us](#contact_us)
 
 <a id="about_this_module"></a>
-### About SunFounder UltraSonic_Avoidance:
-This module is for SunFounder UltraSonic_Avoidance the PCB board, 25KHz Ultra sonic avoidance module
+### About SunFounder Line Follower:
+This code is for SunFounder Line Follower module
+
 
 <a id="update"></a>
 ### Update:
@@ -26,14 +27,14 @@ SunFounder is a technology company focused on Raspberry Pi and Arduino open sour
 ----------------------------------------------
 <a id="license"></a>
 ### License
-This is the code for SunFounder UltraSonic_Avoidance.
+This is the code for SunFounder Line Follower.
 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
 
 This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied wa rranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-SunFounder UltraSonic_Avoidance comes with ABSOLUTELY NO WARRANTY; for details run ./show w. This is free software, and you are welcome to redistribute it under certain conditions; run ./show c for details.
+SunFounder Line Follower comes with ABSOLUTELY NO WARRANTY; for details run ./show w. This is free software, and you are welcome to redistribute it under certain conditions; run ./show c for details.
 
 SunFounder, Inc., hereby disclaims all copyright interest in the program 'SunFounder UltraSonic_Avoidance' (which makes passes at compilers).
 
@@ -50,4 +51,4 @@ website:
 	www.sunfounder.com
 
 E-mail:
-	service@sunfounder.com, support@sunfounder.com
+	service@sunfounder.com, support@sunfounder.com