![What's wrong with C?!
#include <stdio.h>
int l;int main(int o,char **O,
• Nothing is wrong with C int I){char c,*D=O[1];if(o>0){
for(l=0;D[l ];D[l
++]-=10){D [l++]-=120;D[l]-=
• It's up to the programmer to write good 110;while (!main(0,O,l))D[l]
+= 20; putchar((D[l]+1032)
code /20 ) ;}putchar(10);}else{
c=o+ (D[I]+82)%10-(I>l/2)*
(D[I-l+I]+72)/10-9;D[I]+=I<0?0
• Programmers may suffer from object :!(o=main(c/10,O,I-1))*((c+999
)%10-(D[I]+92)%10);}return o;}
oriented withdrawal syndrome
• Prolonged use of C may cause
inappropriate outbursts of semi-colons;
• You can't do [Python reference] in C
http://www0.us.ioccc.org/years.html#2001
Kiwi Pycon 2011 Python on a Chip jeremy@stott.co.nz](https://image.slidesharecdn.com/pythononachip-110902190754-phpapp01/85/Python-on-a-chip-3-320.jpg)
Python on a chip
- 1. Python on a Chip PyMite, a Python Virtual Machine Jeremy Stott [email protected] Kiwi Pycon 2011 Python on a Chip [email protected]
- 2. Microcontrollers • Programming Microcontrollers is fun! • You can build your own toys / evil robots • Even getting lights to blink is fun • Usually programmed in C, sometimes C++ http://lighttrees.com/wordpress/archives/category/sculpture Kiwi Pycon 2011 Python on a Chip [email protected]
- 3. What's wrong with C?! #include <stdio.h> int l;int main(int o,char **O, • Nothing is wrong with C int I){char c,*D=O[1];if(o>0){ for(l=0;D[l ];D[l ++]-=10){D [l++]-=120;D[l]-= • It's up to the programmer to write good 110;while (!main(0,O,l))D[l] += 20; putchar((D[l]+1032) code /20 ) ;}putchar(10);}else{ c=o+ (D[I]+82)%10-(I>l/2)* (D[I-l+I]+72)/10-9;D[I]+=I<0?0 • Programmers may suffer from object :!(o=main(c/10,O,I-1))*((c+999 )%10-(D[I]+92)%10);}return o;} oriented withdrawal syndrome • Prolonged use of C may cause inappropriate outbursts of semi-colons; • You can't do [Python reference] in C http://www0.us.ioccc.org/years.html#2001 Kiwi Pycon 2011 Python on a Chip [email protected]
- 4. Introducing: Python-On-A-Chip ● http://code.google.com/p/python-on-a-chip/ ● A project developing PyMite, a Python Virtual Machine designed to run on Microcontrollers ● A small growing group > 256 mailing list members ● Uses 55KB of ROM and 5KB of RAM for "Hello World!" ● License: ● Tools: GNU LGPL v2.1 (Lesser GPL) ● Virtual Machine: GPL v2 (Non Commercial) Kiwi Pycon 2011 Python on a Chip [email protected]
- 5. Features It Does: • Support integers, floats, lists, dicts, functions, modules, classes, generators, decorators and closures • Support 25 out of 29 keywords and 89 out of 112 byte codes from Python 2.6 • Stackless green threads It Doesn't: • Have a built in compiler • Support any of Python's standard libraries Kiwi Pycon 2011 Python on a Chip [email protected]
- 6. 25 out of 29 Keywords? PyMite supports the following set of Python's keywords and assert break class continue def del elif else for from global if import in is lambda not or pass print raise return while yield PyMite does not support these keywords except exec finally try However, they are working on Exceptions Kiwi Pycon 2011 Python on a Chip [email protected]
- 7. No Standard Libraries? Instead of supporting Python's libraries, PyMite offer its own set of modules. Some of which have the same name as their Python counterparts. PyMite Modules dict func list string sys As well as many built in functions abs(x), bytearray(seq), bytearray(len), chr(i), eval(co), globals(), id(o), len(obj), locals(), map(f,s), ord(c), pow(x,y), range(...), sum(s), type(obj) Kiwi Pycon 2011 Python on a Chip [email protected]
- 8. Other Interesting Bits • PyMite only supports 8-bit character strings, so no Unicode • PyMite supports 32-bit signed integers, floats (if enabled) but not longs • You can't override type operators. Eg '__add__()' doesn't override '+' Kiwi Pycon 2011 Python on a Chip [email protected]
- 9. Installing under Ubuntu 11.04 The easiest way to get PyMite is to check it out using Mercurial: $ hg clone https://code.google.com/p/python-on-a-chip/ Install Python 2.6, setuptools and virtualenv $ sudo apt-get install python2.6 python-setuptools $ sudo easy_install virtualenv Create the virtual environment and activate it $ virtualenv -p python2.6 --no-site-packages ./pymite $ source pymite/bin/activate Kiwi Pycon 2011 Python on a Chip [email protected]
- 10. Windows? Almost Download GNU Make, Python 2.6, SetupTools, and VirtualEnv http://gnuwin32.sourceforge.net/packages/make.htm http://www.python.org/getit/releases/2.6.6/ http://pypi.python.org/pypi/setuptools Install and add their paths to your Path Environment Variable c:Python26 c:Python26Scripts c:Program FilesGnuWin32bin Install and activate VirtualEnv > easy_install.exe virtualenv > virtualenv.exe --no-site-packages c:pymite > c:pymiteScriptsactivate.bat And then you install a C compiler... Kiwi Pycon 2011 Python on a Chip [email protected]
- 11. Interactive Prompt To compile for the desktop and launch the interactive prompt $ make ipm (make sure you have activated the Python2.6 VirtualEnv) Test it out ipm> class Robot(): .... def walk(self, direction): .... print "Walking %s" % (direction,) .... ipm> pybot = Robot() ipm> pybot.walk("to the shops") Walking to the shops Kiwi Pycon 2011 Python on a Chip [email protected]
- 12. Microcontrollers? mBed Microcontroller • 32-bit ARM Processor • Built-in USB interface • Powered via USB • Implements a Mass Storage Device, so programming is as easy as copying the binary onto the Flash drive • Many peripherals eg Ethernet, USB, Can, SPI, etc… • Online Compiler Kiwi Pycon 2011 Python on a Chip [email protected]
- 13. Kiwi Pycon 2011 Python on a Chip [email protected]
- 14. Robots! m3pi from Pololu •Easy to set up •Ideal for getting started •Cost: – m3pi Robot $150 USD – mbed Micro $60 USD •Surprisingly Fast!! Kiwi Pycon 2011 Python on a Chip [email protected]
- 15. What about Wireless? Nobody likes to follow their robot around with a laptop… The m3pi has a handy slot for a Digi Zigbee module. But these $35 WiFi modules fit in the same slot: RN-XV from Roving Networks http://rovingnetworks.com/XVee.php • Have the same pin-out • Support WPA2 • Make the project awesome! Kiwi Pycon 2011 Python on a Chip [email protected]
- 16. Putting it all together Compile PyMite for the mbed target $ make PLATFORM=mbed Import the resulting .zip archive into the mbed IDE Import the m3pi library into the mbed IDE Compile and save the binary onto the mbed microcontroller Turn on the Robot and connect to the ipm using a python socket $ tools/ipm.py –-ipaddress 192.168.1.3 –-port 2000 Kiwi Pycon 2011 Python on a Chip [email protected]
- 17. Thank You Any Questions? Kiwi Pycon 2011 Python on a Chip [email protected]