Download Python / PyS60

Symbian OS
Python / PyS60
1
Andreas Jakl, 2009
v1.2 – 01 March 2009
PyS60 – Examples
●
ShakerRacer
www.youtube.com/watch?v=EMjAYdF13cU
2
Andreas Jakl, 2009
PyS60 – Examples
●
PyWuzzler (Benjamin Gmeiner, Yen-Chia Lin)
3
Andreas Jakl, 2009
PyS60 – Examples
●
Controlling Super Mario
by movements (jumping,
walking, ...)
NiiMe
Playing drums
Controlling flight / racing
games with tilting
http://www.niime.com/
4
Andreas Jakl, 2009
PyS60 – Examples
Time-lapse Photography
http://blog.foozia.com/blog/2007/jan/21/python-s60-time-lapse-photography-using-nokia-n80/
aspyplayer
Last.fm-Player for PyS60
http://code.google.com/p/aspyplayer/
pyPoziomica
Use your phone as a level tool
http://www.symbian-freak.com/news/007/12/pypoziomica_freeware_level_tool.htm
PyED
Edit Python source code on the phone
http://sourceforge.net/projects/pyed/
5
Andreas Jakl, 2009
What is it all about?
Python
6
Andreas Jakl, 2009
Python
●
Older than you might think:
1989 – 1991 by Guido van Rossum (National Research
Institute for Mathematics and Computer Science,
Netherlands)
Named after Monty Python’s Flying Circus
●
Today:
Microcontrollers
Mobile Phones
Web servers
7
Andreas Jakl, 2009
Scalable
●
Modular architecture
●
Easy code reuse
●
Huge Python standard library
●
Extension with own C/C++ modules
Shell scripts
Huge projects
8
Andreas Jakl, 2009
Mature
Object
oriented,
memory
manager
9
Helpful
error
messages,
exception
handling
Interpreted
& bytecompiled
Andreas Jakl, 2009
Very high
level
Fast
●
Rapid Application Prototyping
●
Easy to learn – can you read this code?
import inbox, audio
box = inbox.Inbox()
msg_id = box.sms_messages()[0]
msg_txt = u"Message: " + box.content(msg_id)
audio.say(msg_txt)
●
What would this be like in C++ or Java ME? ...
10
Andreas Jakl, 2009
Symbian OS + Runtimes
Java ME
Python
.net
Basic
Perl
Apache /
PHP / MySQL
Widgets
(Web
Runtime)
Flash Lite
Silverlight
(soon)
Ruby
S60
(C++)
Symbian OS
11
Andreas Jakl, 2009
UI Platforms: S60
●
Unified UI platform based on S60
Official UI platform of
Symbian Foundation
Former name: Series 60
Nokia N97
12
●
Touchscreen support with S60 5th
Edition
Andreas Jakl, 2009
UI Platforms: S60
www.s60.com
Business
High-End Multimedia
Mass Market
Nokia N96
Nokia E66
Samsung Omnia HD
Nokia 6121 Classic
Nokia 5800
XPressMusic
Nokia E71
Nokia N85
SE Idou
Nokia E90
13
Samsung INNOV8
Andreas Jakl, 2009
Nokia 5500 Sport
Nokia 6210 Navigator
●
Python port to S60
●
Allows easy access to:
Accelerometer
Camera
Text-to-speech
Location
Ease of development
PyS60
Web
Managed
code
Java
Native code
Symbian
C++
Functionality and performance
Bluetooth
UI
14
Python
P.I.P.S.
Web services
Messaging
Flash
Andreas Jakl, 2009
Setup – Phone
●
●
Install the latest Nokia PC Suite:
http://europe.nokia.com/A4144903
PyS60 1.4.x: based on
Python 2.3
PyS60 1.9.2+: based on
Python 2.5.1, supports
new sensor framework
of S60 3rd Ed., FP2+
Download and install PyS60:
1.4.x: http://sourceforge.net/projects/pys60/
1.9.x+: https://garage.maemo.org/projects/pys60/
●
Phone:
Phone software: PythonForS60_1_x_x_3rdEd.SIS
Phone script shell: PythonScriptShell_1_x_x_3rdEd.SIS
15
Andreas Jakl, 2009
Setup – PC
●
Extract SDK plug-in to the S60 SDK:
PythonForS60_1_x_x_SDK_3rdEd.zip
16
Andreas Jakl, 2009
IDEs
●
IDLE – comes with Python SDK
C:\Program
Files\Python\Lib\idlelib\idle.bat
●
PythonWin + Win32 Extensions
http://sourceforge.net/projects/pywi
n32/
●
PyDev Eclipse/Carbide.c++ Plug-in
http://pydev.sf.net/
●
SPE
http://pythonide.stani.be/
17
Andreas Jakl, 2009
Hello World
●
Create a file hello.py:
hello.py
print “Hello World”
●
●
●
Connect your phone to the PC (“PC Suite” connection
mode)
Transfer the script to E:\Python\ (memory card) using
the Nokia PC suite file manager
Run the script:
18
Andreas Jakl, 2009
Hello World – Emulator
●
●
Copy hello.py to:
<epocroot>\winscw\c\python\hello.py
Start the emulator from:
<epocroot>\release\winscw\udeb\epoc.
exe
19
Andreas Jakl, 2009
PyDev + Emulator
●
●
Either create the project / workspace directly in the
python-dir of the emulator
Or link the project files to source files in the dir:
20
Andreas Jakl, 2009
Starting with the UI
PyS60 – User Interface
21
Andreas Jakl, 2009
Module
●
●
Collection of related functions and data grouped
together
Has to be imported at the beginning:
import appuifw
●
Addressing a function of the module:
appuifw.query(label, name)
●
Import multiple modules in a single statement:
import appuifw, e32
22
Andreas Jakl, 2009
import appuifw
Query
appuifw.query(u"Type a word:", "text", u"Hello")
appuifw.query(u"Type a number:", "number", 7)
appuifw.query(u"Type a date:", "date")
appuifw.query(u"Type a time:", "time")
appuifw.query(u"Type a password:", "code")
appuifw.query(u"Do you like PyS60?", "query")
Syntax: appuifw.query(label,
text
23
number /
float
date
type[, initial value])
time
Andreas Jakl, 2009
code
query
import appuifw
Note Dialog
appuifw.note(u"Hello")
appuifw.note(u"File not found", "error")
appuifw.note(u"Upload finished", "conf")
Syntax: appuifw.note(text[,
info /
default
24
type[, global] ] )
error
Andreas Jakl, 2009
conf
Variables
●
Variables not declared ahead of time
●
Implicit typing
●
Automated memory management
Reference counting, garbage collection
●
Variable names can be “recycled”
●
del statement allows explicit de-allocation
25
Andreas Jakl, 2009
Variables – Example
age = 5
name = u"Andreas"
# u in front of the string: unicode
name += age
name += str(age)
# Doesn't work, the type isn’t converted automatically
# name == Andreas5
name = age
# name now points to the same object as age; name == 5
foo = "xyz"
bar = foo
foo
“xyz”
# bar points to the same object as foo
bar
foo = 123
26
# a new object is created for foo, bar still points to "xyz“
Andreas Jakl, 2009
foo
“xyz”
bar
123
Multi-Query Dialog
●
Syntax: appuifw.multi_query(label1,
import appuifw
pwd = u"secret"
info = appuifw.multi_query(u"Username:", u"Password:")
if info:
// returns a tuple with the info
login_id, login_pwd = info
if login_pwd == pwd:
appuifw.note(u"Login successful", "conf")
else:
appuifw.note(u"Wrong password", "error")
else:
// returns None – special type
appuifw.note(u"Cancelled")
27
Andreas Jakl, 2009
label2)
if-statement
●
Works like in other languages
●
Blocks are defined by indentation – avoids dangling else
●
if expression1:
expr1_true_suite
elif expression2:
expr2_true_suite
else:
none_of_the_above_suite
28
Andreas Jakl, 2009
Lists, Tuples and Dictionaries
●
Generic “arrays” for arbitrary number of arbitrary
objects
●
Ordered and accessed via index offsets
●
List – created using [ ]
myList = [1, 2, 3, 4] # [1, 2, 3, 4]
print myList[0]
#1
# Subsets: sequence[starting_index:ending_index]
print myList[1:3]
# [2, 3]
print myList[2:]
# [3, 4]
print myList[:3]
# [1, 2, 3]
myList[1] = 5
# [1, 5, 3, 4]
myList[2] = ["bla", (-2.3+4j)] # [1, 5, ["bla", (-2.3+4j)], 4]
print myList[2][1]
# -2.3+4j
print 4 in myList
# True
29
Andreas Jakl, 2009
Lists, Tuples and Dictionaries
●
Tuple – created using ( )
Immutable – can therefore be used as dictionary keys
Also useful when you don’t want a function to be able to
change your data
myTuple1 = ('python', 's60', 27)
print myTuple1[0]
# python
myTuple[1] = 'no'
# tuples are immutable – exception!
myTuple2 = ('symbian', 'uiq')
myTuple3 = myTuple1 + myTuple2
print myTuple3
# ('python', 's60', 27, 'symbian', 'uiq')
30
Andreas Jakl, 2009
Lists, Tuples and Dictionaries
●
Dictionary – created using { }
Mapping type – like associative arrays or hashes in Perl
Key-value pairs
–
–
Keys: almost any Python type, usually numbers or stings
Values: arbitrary Python object
myDict = {'planet': 'earth'}
myDict['port'] = 80
print myDict
# {'planet': 'earth', 'port': 80}
print myDict.keys() # ['planet', 'port']
print myDict['planet'] # earth
for key in myDict:
print "key=%s, value=%s" % (key, myDict[key])
# key=planet, value=earth
# key=port, value=80
31
Andreas Jakl, 2009
Popup Menu
●
Syntax: appuifw.popup_menu(list[,
import appuifw
items = [u"The Journey", u"RealReplay", u"ShakerRacer"]
index = appuifw.popup_menu(items, u"Buy:")
if index == 0:
appuifw.note(u"Great choice")
elif index == 1:
appuifw.note(u"Cool")
elif index == 2:
appuifw.note(u"I like that")
elif index == None:
appuifw.note(u"Purchase cancelled")
32
Andreas Jakl, 2009
label ])
Selection List
●
Search field appears
after pressing a letter key
Syntax: appuifw.selection_list(choices[,
import appuifw
names = [u"Michael", u"Devon", u"Bonnie", u"April", u"RC3"]
index = appuifw.selection_list(names, 1)
if index == 2:
print "I love you!"
else:
print "You're great!"
33
Andreas Jakl, 2009
search_field=0])
Multi-Selection List
●
Syntax: appuifw.multi_selection_list(
choices[, style=„checkbox‟, search_field=0])
import appuifw
names = [u"Michael", u"Devon", u"Bonnie", u"April", u"RC3"]
selections = appuifw.multi_selection_list(names, 'checkbox', 1)
print selections
Style: checkmark
Select multiple items with the pen key
Not really important
34
Andreas Jakl, 2009
for loop
●
●
for iter_var in iterable:
suite_to_repeat
With each loop, iter_var set to current element of
iterable
Similar to foreach in other languages
35
Andreas Jakl, 2009
for Loop – Examples
# Iterating over a string
for eachLetter in "Text":
print "current letter:", eachLetter
# Iterating by sequence item
nameList = ["Mike", "Sarah", "Charles"]
for eachName in sorted(nameList):
print eachName
# Iterating by sequence index
for nameIndex in range(len(nameList)):
print nameList[nameIndex]
# Iterate over a range
for eachVal in range(3):
print "value: ", eachVal
Mike
Sarah
Charles
value: 0
value: 1
value: 2
# Extended syntax:
# range(start, end, step = 1)
for eachVal in range(2, 10, 3):
print "value: ", eachVal
36
current letter: T
current letter: e
current letter: x
current letter: t
Charles
Mike
Sarah
value: 2
value: 5
value: 8
Andreas Jakl, 2009
while loop
●
●
while expression:
suite_to_repeat
Nice addition: else is executed if loop was not
abandoned by break
def showMaxFactor(num):
count = num / 2
while count > 1:
if num % count == 0:
print "Largest factor of %d is %d" % (num, count)
break
count -= 1
else:
print num, "is prime"
for eachNum in range(10, 21):
showMaxFactor(eachNum)
37
Andreas Jakl, 2009
Example – System Info SMS
import appuifw, messaging, sysinfo
# You could use a dictionary as well, but here this is more straightforward later on
infoNames = [u"Profile", u"Battery", u"Signal DBM"]
infoCalls = ["sysinfo.active_profile()", "sysinfo.battery()", "sysinfo.signal_dbm()"]
# Let the user choose the information he wants to send
choices = appuifw.multi_selection_list(infoNames, "checkbox", 0)
infoSms = ""
for idx in choices:
# Execute the statement(s) stored in the infoCalls-list through the eval-statement,
# convert the result to a string and append it to the sms text
infoSms += infoNames[idx] + ": " + str(eval(infoCalls[idx])) + "; "
# Query the telephone number
smsNum = appuifw.query(u"Number:", "text", u"+15550135")
if smsNum:
# Send the SMS if the user didn’t cancel
messaging.sms_send(smsNum, infoSms)
appuifw.note(u"Info sent", "conf")
38
Andreas Jakl, 2009
Procedural and Object Oriented Development
Python – Function and Classes
39
Andreas Jakl, 2009
Functions – Basics
●
●
def function_name(arguments):
[“function_documentation_string”]
function_body_suite
Supports:
def foo():
"foo() -- does't do anything special."
print "in foo"
Default arguments
Variable length arguments
Multiple return values
Inner functions
# Execute the function
foo()
# Print the help text of the function
print foo.__doc__
# foo() -- does't do anything special.
...
40
Andreas Jakl, 2009
Functions – Default Arguments
●
Default arguments:
def func(posargs, defarg1=dval1, defarg2=dval2, ...):
def calcTax(amount, rate=0.0275):
return amount + (amount * rate)
print calcTax(100)
# 102.75
print calcTax(100, 0.05)
# 105.0
41
Andreas Jakl, 2009
Functions – Variable Length Arguments
●
Variable length arguments (unknown number):
Non-keyword variable arguments (tuple):
def func([formal_args,] *vargs_tuple):
Argument with * will hold all remaining arguments once all
formal parameters have been exhausted
Keyword variable arguments (dictionary):
def func([formal_args,][*vargst,] **vargsd):
def tupleVarArgs(arg1, arg2='defaultB', *theRest):
print "formal arg 1: ", arg1
print "formal arg 2: ", arg2
for eachXtraArg in theRest:
print 'another arg: ', eachXtraArg
42
Andreas Jakl, 2009
tupleVarArgs('abc')
# formal arg 1: abc
# formal arg 2: defaultB
tupleVarArgs('abc', 123, 'xyz', 123.456)
# formal arg 1: abc
# formal arg 2: 123
# another arg: xyz
# another arg: 123.456
global_str = "foo"
●
local scope
Variable Scope
Global scope
Declared outside a function
def foo():
local_str = "bar"
return global_str + local_str
print foo()
Lifespan lasts as long as script is running
●
Local scope
Live temporarily as long as function they are defined in is
active
●
Searching for identifiers
First local, then global
Possible to override global variables by creating a local one
43
Andreas Jakl, 2009
Variable Scope
Writing to global variables in functions:
Creates a new local variable
(pushes global variable out of scope)
global statement specifically references a named global
variable
def foo():
bar = 200
print "in foo(), bar is", bar
bar = 100
print "in __main__, bar is", bar
foo()
print "in __main__, bar still is", bar
in __main__, bar is 100
in foo(), bar is 200
in __main__, bar still is 100
44
def foo():
global bar
bar = 200
print "in foo(), bar is", bar
bar = 100
print "in __main__, bar is", bar
foo()
print "in __main__, bar is now", bar
in __main__, bar is 100
in foo(), bar is 200
in __main__, bar is now 200
Andreas Jakl, 2009
local scope
local scope
●
Classes
●
●
●
class MyObject(bases):
“Documentation text”
class_suite
New style classes should be derived from any other
class or from object
Simplest use: container object for instance attributes
Not defined in class definition
Only valid for this instance
45
class MyData(object):
pass
# code is required syntactically,
# but no operation is desired
mathObj = MyData()
mathObj.x = 4
mathObj.y = 5
Andreas Jakl, 2009 print mathObj.x * mathObj.y # 20
Classes – Subclasses, Methods
●
__init__
similar to constructor
●
def updateId(self, newId):
self.id = newId
self-parameter
Passes reference to
current instance
Not needed for static
or class methods
Python wants to be
explicitly clear
46
class LibraryEntry(object):
def __init__(self, id, title):
self.id = id
self.title = title
class LibraryBook(LibraryEntry):
def __init__(self, id, title, author):
LibraryEntry.__init__(self, id, title)
self.author = author
def updateAuthor(self, newAuthor):
self.author = newAuthor
libBook = LibraryBook(1, "PyS60", "Andreas Jakl")
libBook.updateId(2)
libBook.updateAuthor("Nokia")
Andreas Jakl, 2009
Classes – Attributes
●
Instance attributes are set “on-the-fly” by using them
Constructor is the first place to set instance attributes
Use default arguments for default instance setup
●
Class variables / static data have to be defined
class Letter(object):
def __init__(self, text, author="Andreas Jakl", category=“love"):
self.text = text
self.author = author
self.category = category
def printLetter(self):
print self.text, self.author, self.category
loveLetter = Letter("I love you")
print dir(loveLetter)
# Print all methods & attributes of this class
47
Andreas Jakl, 2009
class C(object):
foo = 100
# Static data
print C.foo
# 100
C.foo = C.foo + 1
print C.foo
# 101
['__class__', '__delattr__', '__dict__', '__doc__',
'__getattribute__', '__hash__', '__init__',
'__module__', '__new__', '__reduce__',
'__reduce_ex__', '__repr__', '__setattr__',
'__str__', '__weakref__', 'author', 'category',
'printLetter', 'text']
How to organize your application
PyS60 – Application Structure
48
Andreas Jakl, 2009
Application Structure
Title appuifw.app.title
Navigation pane appuifw.app.set_tabs()
Body appuifw.app.body
Dialog appuifw.<dialog_function>
- appuifw.query()
- appuifw.note()
- ...
49
Menu
Exit appuifw.app.
appuifw.app.menu
exit_key_handler
Andreas Jakl, 2009
UI App – Example
import appuifw, e32
def quit():
print "Exit key pressed"
app_lock.signal()
appuifw.app.exit_key_handler = quit
appuifw.app.title = u"UI App"
print "App is now running"
app_lock = e32.Ao_lock()
app_lock.wait()
print "Application exits"
50
Andreas Jakl, 2009
Callback Function
●
No difference to normal functions
●
Associating function with event: binding
Use function name without () to get the function object
Compare to function pointers in C
def quit():
pass # function is empty (instead of {} in C++ / Java)
appuifw.app.exit_key_handler = quit
51
Andreas Jakl, 2009
Wait for the User
●
Previously: app. exited after executing all lines
●
Event based UI-app: wait for user input
...
app_lock = e32.Ao_lock() # Create an instance of an Ao_lock object
app_lock.wait()
Waiting for
events
52
quit() call-back handler
app_lock.signal()
Andreas Jakl, 2009
Refer to the Symbian OS
course for more
information about
Active Objects
Application Body
appuifw.app.screen = “normal"
53
appuifw.app.screen = “large"
Andreas Jakl, 2009
appuifw.app.screen = "full"
Application Body
●
You can assign several objects to the body
Canvas: provides drawable screen area + support for
handling raw key events
Form: complex forms with various input fields
Listbox: shows a list of items (single- or double-line-item)
Text: free-form text input
54
Andreas Jakl, 2009
Application Menu
●
Defined using tuples:
Text
Call-back function
–
Specify another
tuple instead to
define a submenu
import appuifw, e32
def play():
print "Play file"
def volume_up():
print "Volume up"
def volume_down():
print "Volume down"
def quit():
print "Exit key pressed"
app_lock.signal()
appuifw.app.exit_key_handler = quit
appuifw.app.title = u"mp3 Player"
appuifw.app.menu = [(u"Play", play),
(u"Volume", ( (u"Up", volume_up), (u"Down", volume_down) ) )]
print "App is now running"
app_lock = e32.Ao_lock()
app_lock.wait()
submenu
Example based on [1]
55
Andreas Jakl, 2009
String Manipulation
txt = "I like Python"
url = " http://www.mopius.com "
url = url.strip()
if url.startswith("http://"):
print url, "is a valid URL"
print txt[2:6]
print txt.find("like")
if txt.find("love") == -1:
print "What's wrong with you?"
txt.replace("like", "love")
webServiceInput = " 1, 2, 3, 4"
print webServiceInput.replace(" ", "")
print txt.upper()
print "Length", len(txt)
txt = "one;two;three"
print txt.split(";")
txt2 = ""
if txt2:
print "txt2 contains characters"
else:
print "txt2 doesn't contain characters"
http://www.mopius.com is a valid URL
1,2,3,4
['one', 'two', 'three']
like
2
What's wrong with you?
I LIKE PYTHON
Length 13
txt2 doesn't contain characters
56
Andreas Jakl, 2009
String Formatting
●
String slicing like for lists: [start:end]
●
Assemble string based on other variables:
print "Host: %s\tPort: %d" % ("Earth", 80)
print "DD.MM.YYYY = %02d.%02d.%d" % (12, 3, 82)
list = [3, 2, 1, "go"] # A list has to be converted to a tuple first
print "Counting: %d, %d, %d, %s" % tuple(list)
Symbol Conversion
Host: EarthPort: 80
DD.MM.YYYY = 12.03.82
%s
String conversion via str() prior
Counting: 3, 2, 1, go
to formatting
%d
Signed decimal integer
%f
Floating point real number
...
...
57
Andreas Jakl, 2009
Example – Inbox Search
import inbox, appuifw
# Create an instance of the Inbox object
box = inbox.Inbox()
# Query search phrase
query = appuifw.query(u"Search for:", "text").lower()
hits = []
ids = []
# sms_messages() returns message IDs for all messages in the SMS inbox
for sms_id in box.sms_messages():
# Retrieve the full message text and convert it to lowercase
msg_text = box.content(sms_id).lower()
if msg_text.find(query) != -1:
# If the text was found, store a preview
hits.append(msg_text[:25])
ids.append(sms_id)
# Display all results in a list
index = appuifw.selection_list(hits, 1)
if index >= 0:
# Show the full text of the selected message
appuifw.note(box.content(ids[index]))
58
Andreas Jakl, 2009
Event Loop
●
e32.Ao_lock waits for events, but stops execution
●
Game:
App. has to be active all the time
But still needs respond to events (keys, ...)
Initialize event call-backs
while <end condition>:
Update game state
Redraw screen
Pause / yield
59
Sleep (+ execute waiting active objects):
 e32.ao_sleep(interval)
Yield (just execute ready active objects with
higher priority)
 e32.ao_yield()
Andreas Jakl, 2009
The Python way of
Exception Handling
60
Andreas Jakl, 2009
Exceptions
●
Example:
Exception “NameError” raised by the interpreter:
>>> print foo
Traceback (most recent call last):
File “<stdin>", line 1, in <module>
print foo
NameError: name 'foo' is not defined
61
Andreas Jakl, 2009
Exceptions
●
try:
try_suite
# watch for exceptions here
except Exception[, reason]:
except_suite
# exception-handling code
●
Different objects derived from Exception
●
Exception arguments / reasons:
May be passed along
Not just a string, but contains more information
62
Andreas Jakl, 2009
Exceptions – Information
try:
f = file(u"c:\\python\\test.txt", "w+")
print >> f, "Welcome to Python"
f.seek(0)
print "File contents:", f.read()
f.close()
except IOError, reason:
print reason
print reason.filename
print reason.errno
print reason.strerror
63
[Errno 2] No such file or
directory: u'c:\\python\\test.txt'
c:\python\test.txt
2
No such file or directory
Andreas Jakl, 2009
Multiple Exceptions
●
Catching multiple exceptions:
Multiple except-statements
Multiple exceptions in one except statement
Catch the base class Exception
(no good coding style – you might be silently dropping
errors)
64
Andreas Jakl, 2009
Code Examples
●
Code snippets for:
Camera
Text to Speech
Sound recording / playing
Bluetooth
Networking
Graphics, UI
3D (Open GL ES)
Camera
Sensor
...
65
http://www.mobilenin.com/pys60/menu.htm
Additional modules:
http://cyke64.googlepages.com/
Andreas Jakl, 2009
Bonus – Acceleration Sensor (3rd Ed (FP1))
import appuifw,e32,sensor
def get_sensor_data(status):
"Callback function for regular accelerometer status"
print "x: %d, y: %d, z: %d" % (status['data_1'], status['data_2'], status['data_3'])
def exit_key_handler():
# Disconnect from the sensor and exit
acc_sensor.disconnect()
app_lock.signal()
appuifw.app.exit_key_handler = exit_key_handler
# Retrieve the acceleration sensor
sensor_type = sensor.sensors()['AccSensor']
# Create an acceleration sensor object
acc_sensor = sensor.Sensor(sensor_type['id'],sensor_type['category'])
# Connect to the sensor
acc_sensor.connect(get_sensor_data)
# Wait for sensor data and the exit event
app_lock = e32.Ao_lock()
app_lock.wait()
66
Andreas Jakl, 2009
Bonus – Acceleration Sensor (3rd Ed FP2+)
from sensor import *
import e32, time, appuifw
class DemoApp():
def __init__(self):
self.accelerometer = AccelerometerXYZAxisData(data_filter=LowPassFilter())
self.accelerometer.set_callback(data_callback=self.my_callback)
self.counter = 0
def my_callback(self):
# For stream sensor data the callback is hit 35 times per sec (On 5800).
# The device cannot handle resource hungry operations like print in the callback function
# for such high frequencies. A workaround is to sample the data as demonstrated below.
if self.counter % 5 == 0:
print "X:%s, Y:%s, Z:%s" % (self.accelerometer.x,
self.accelerometer.y, self.accelerometer.z)
self.counter = self.counter + 1
def run(self):
self.accelerometer.start_listening()
def exit_key_handler():
# Disconnect from the sensor and exit
global d
d.accelerometer.stop_listening()
print "Exiting Accelorometer"
app_lock.signal()
if __name__ == '__main__':
appuifw.app.exit_key_handler = exit_key_handler
d = DemoApp()
d.run()
app_lock = e32.Ao_lock()
67
app_lock.wait()
Andreas Jakl, 2009
Literature – Recommended
Mobile Python
Jürgen Scheible, Ville Tuulos
Complete overview of Python development for PyS60, many
small code samples.
Status: Symbian OS 9, PyS60 1.4, 2007
Free code samples:
http://www.mobilenin.com/pys60/menu.htm
Core Python Programming (Second Edition)
Wesley J. Chun
Python for developers who already know other languages.
Comprehensive short overview, in later chapters a detailed
overview of the individual components.
Status: 2007
68
Andreas Jakl, 2009
That’s it!
Thanks for your attention
69
Andreas Jakl, 2009