My kiwi PyCon slides for the robotic arm demonstration. Github is at https://github.com/lizquilty/roboticarm/ should you need the code

1. Hacking the OWI/Maplin
Robotic Arm
By Liz Quilty

2. Confession
I don’t really know python.
My way is possibly not the best
I just like making things, and having fun :)

3. Items Required
1 OWI/Maplin Robotic Arm kit

4. Items Required
1 USB kit for the arm

5. Items Required
1 Raspberry Pi + power/network etc

6. Items Required
A sick/bored child to assemble robotic arm

7. Setup Your Raspberry Pi
Partition and install raspbian
http://elinux.org/RPi_Easy_SD_Card_Setup
Unpack this to the SD card as instructed
Set up networking and connect via SSH

8. Adding Dev rules
Create the file /etc/udev/rules.d/85-robotarm.rules with the
contents
SUBSYSTEM=="usb", ATTRS{idVendor}=="1267", ATTRS{idProduct}=="0000", ACTION=="add",
GROUP="plugdev", MODE="0666"
This allows non root users to access it.
For CGI add apache user to plugdev group
usermod -aG plugdev www-data
usermod -aG audio www-data

9. pyUSB
Install the custom pyUSB
pyusb http://sourceforge.net/projects/pyusb
# wget "http://downloads.sourceforge.net/project/pyusb/PyUSB%201.0/1.0.0-
alpha-3/pyusb-1.0.0a3.zip?r=http%3A%2F%2Fsourceforge.net%2Fprojects%
2Fpyusb%2F&ts=1377736820&use_mirror=hivelocity"
# unzip pyusb-1.0.0a3.zip
# cd pyusb
# python setup.py build
# python setup.py install

10. Command Line
Quick and easy
https://github.com/lizquilty/roboticarm/
Better for more complex stuff
https://github.com/peterlavelle/maplinarm

11. Setting up the functions
#ROBOT ARM CONTROL PROGRAM
#import the USB and Time librarys into Python
import usb.core, usb.util, time
#Allocate the name 'RoboArm' to the USB device
RoboArm = usb.core.find(idVendor=0x1267, idProduct=0x000)
#Check if the arm is detected and warn if not
if RoboArm is None:
raise ValueError("Arm not found")
#Create a variable for duration
Duration=1
#Define a procedure to execute each movement
def MoveArm(Duration, ArmCmd):
#Start the movement
RoboArm.ctrl_transfer(0x40,6,0x100,0,ArmCmd,1000)
#Stop the movement after waiting a specified duration
time.sleep(Duration)
ArmCmd=[0,0,0]
RoboArm.ctrl_transfer(0x40,6,0x100,0,ArmCmd,1000)

12. Moving
MoveArm(1,[0,1,0]) #Rotate base anti-clockwise
MoveArm(1,[0,2,0]) #Rotate base clockwise
MoveArm(1,[64,0,0]) #Shoulder up
MoveArm(1,[128,0,0]) #Shoulder down
MoveArm(1,[16,0,0]) #Elbow up
MoveArm(1,[32,0,0]) #Elbow down
MoveArm(1,[4,0,0]) #Wrist up
MoveArm(1,[8,0,0]) # Wrist down
MoveArm(1,[2,0,0]) #Grip open
MoveArm(1,[1,0,0]) #Grip close
MoveArm(1,[0,0,1]) #Light on
MoveArm(1,[0,0,0]) #Light off

13. Demo Hello World + Waving
PIR sensor connected to + - and pin GPIO pin
18
Sensor detects movement, greets and waves,
then waits

14. Test and use
Test the arm as root
Pick up things, write some code, automate !
Use cron for time based
sensors (motion) http://learn.adafruit.com/adafruits-raspberry-pi-lesson-12-
sensing-movement/hardware
http://learn.adafruit.com/adafruits-raspberry-pi-lesson-4-gpio-setup/configuring-gpio
Speech - festival
Voice control

15. Web Based
Install apache & configure with CGI
https://github.com/lizquilty/roboticarm/

16. Simple UI

17. Demo
● Connect to the Wireless Access point RoboticArm
● Browse to http://10.0.0.2
Try not to overload it :)

18. Speech
Python http://cmusphinx.sourceforge.net/
Google
http://blog.oscarliang.net/raspberry-pi-voice-
recognition-works-like-siri/

19. References
My GitHub https://github.com/lizquilty/roboticarm/
CLI scripts https://github.com/peterlavelle/maplinarm
PyUSB http://sourceforge.net/projects/pyusb
99 little bugs in the code
99 little bugs in the code
Take one down, patch it around
117 little bugs in the code