Diddyborg PS3 Control

It should be possible to do either, but we will start with trying to run the script as a separate file.

Firstly we need to take a copy of a 'clean' python environment to keep the scripts isolated.
We will do this before any other code has run:

#!/usr/bin/env python
# coding: Latin-1

cleanGlobals = globals().copy()
cleanLocals = locals().copy()

# Load library functions we want

Next we want to setup our button variable like last time.
I will use 16 this time, which should correspond to the PS logo button:

# Settings for the joystick
axisUpDown = 1                 # Joystick axis ...
axisUpDownInverted = False     # Set this to Tr...
axisLeftRight = 2              # Joystick axis ...
axisLeftRightInverted = False  # Set this to Tr...
buttonResetEpo = 3             # Joystick butto...
buttonSlow = 8                 # Joystick butto...
slowFactor = 0.5               # Speed to slow ...
buttonFastTurn = 9             # Joystick butto...
buttonArmScript = 16           # Joystick butto...
interval = 0.00                # Time between u...

Now in the event code we will grab the button down event:

            elif event.type == pygame.JOYBUTTONDOWN:
                # A button on the joystick just got pushed down
                hadEvent = True
                if event.button == buttonArmScript:
                    # Stop moving
                    driveLeft = 0.0
                    driveRight = 0.0
                    PBR.MotorsOff()
                    # Run the arm control script
                    execfile('robotic-arm-ps3.py', cleanGlobals.copy(), cleanLocals.copy())
                    # Jump to the next control input
                    break
            elif event.type == pygame.JOYAXISMOTION:

We do this in here to make sure we only see the event once.

There are three commented sections in this code block which do the following:

1. Stop the motors moving
   Remove this if you want him to carry on driving when moving the arm
2. Run the other script
   You may need a ./ or path to the script
   This script will stay on this line until the other script has finished
   By passing a 'clean' copy of the environment we stop the other script affecting the variables in this script
3. Skip to next event
   We do this to avoid interpreting the last state of the controller when the other script ends
   Hopefully pygame.event,get() will not get any events from when the other script was running

The only other thing you need to do is make a button (can be the same one) stop the other script from running.
You can do this by using a global variable to terminate the loop:

global running
running = True
...
def processArm(event):
      global ..., running
      if event.type == pygame.JOYBUTTONDOWN:
          if event.button == ...:
              running = False
              return
    ...
...
try:
    while running:
        ...
    j.quit()    
except KeyboardInterrupt:
    j.quit()

Hopefully that will be enough to allow you to switch between control scripts.

It seems that execfile is not the best way to do this then.
I did some reading and there is a module called runpy that seems to work well.

I tried your code (with the USB bits commented out) and had the same issue.
I then changed to this new method and it appears to work well.

First we remove the old globals / locals copying and import the runpy module:

#!/usr/bin/env python
# coding: Latin-1

# Load library functions we want
import time
import os
import sys
import pygame
import PicoBorgRev
import runpy

The button number is still needed like the previous method:

# Settings for the joystick
axisUpDown = 1                 # Joystick axis ...
axisUpDownInverted = False     # Set this to Tr...
axisLeftRight = 2              # Joystick axis ...
axisLeftRightInverted = False  # Set this to Tr...
buttonResetEpo = 3             # Joystick butto...
buttonSlow = 8                 # Joystick butto...
slowFactor = 0.5               # Speed to slow ...
buttonFastTurn = 9             # Joystick butto...
buttonArmScript = 16           # Joystick butto...
interval = 0.00                # Time between u...

Now in the event code where we grab the button down event we use the runpy module instead:

            elif event.type == pygame.JOYBUTTONDOWN:
                # A button on the joystick just got pushed down
                hadEvent = True
                if event.button == buttonArmScript:
                   # stop moving
                   driveLeft = 0.0
                   driveRight = 0.0
                   PBR.MotorsOff()
                   # Run the arm control script
                   runpy.run_path('./robotic-arm-ps3.py')
                   # Re-initialise the joystick after the script change
                   joystick = pygame.joystick.Joystick(0)
                   joystick.init()
                   # Jump to the next control input
                   break                   
            elif event.type == pygame.JOYAXISMOTION:

Notice I have also added a re-initialisation of the joystick.
When testing this new version it turns out the joystick is no longer running when it returns control.
This way the joystick is started again, allowing the script to continue properly.

This all works fine on my DiddyBorg, except I did not use the USB code.
I also tried with another script which drives an LedBorg from the controller, that worked fine this way.

I forgot to mention that I had to make a slight correction to the loop at the end of your script.

Instead of the while running: being inside the while True:, it needs to replace it.

This is how the loop looks in the version I had running:

try:
    # Run until we receive the quit command
    while running:
        	# Sleep so we don't eat up all the CPU time
        	time.sleep(0.1)
        
        	# read in events
        	events = pygame.event.get()
        
        	# and process them
        	for event in events:
            		processArm(event) 
        
    j.quit()    
except KeyboardInterrupt:
    j.quit()

It sounds like the PS3 controller has run out of battery power and needs to be charged.

Connecting the USB will provide some power, this is what is allowing it to make the connection when attached with a cable.
It will not get very much charge from a few minutes though, hence it runs out of battery fairly quickly when turned on.

If you leave the PS3 remote plugged in to a USB port overnight it should charge up and be ready to go again.
The Raspberry Pi may not have enough power available to charge the remote so I would recommend attaching it to a powered hub or a PC to charge.

You can also attach the controller to a PS3 to charge it, but you may need to re-run the pairing routine afterwards as the PS3 will likely pair the controller to itself.