GMC-GUI Operation

[last updated: 2017-09-24]
GMC GUI project
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Hardware setup:
• Disable touch screen if desired to use an external HDMI
• Attach the Power Shield to the rPi.
  Connect the short micro-USB jumper from the Power Shield "switched power out" USB to the rPi input power USB.
  Connect power to the Power Shield "power in" USB.
• Switch on the "power switch" on the Power Shield to turn on and boot up the rPi.
  Yellow LED 555 interrupt timer will flash every 2sec
  This is a hardware circuit and will blink whenever power is applied, even if no program is running.

  Stretch will boot up.

Software:
• When stretch boots up, it executes /etc/rc.local
  the last line of which is a command to execute autoRunAtStartup.sh script file
  located in /home/pi/Desktop/myDocs/programs/scriptFiles directory
• This script file contains a command to execute:
  AutoRunAtStartup.py
This file is located in Desktop/myDocs/programs/python/AutoRunAtStartup folder, and is currently at rev-08
The code blinks the green HB LED, and reads and responds to 4 PB's on the Power Shield board.
PB04 starts up the GUI by executing GMC_main.py
PB03 quits the program

Upon startup, $ ps axg | grep python

shows that indeed AutoRunAtStartup.py is running.
• Pressing PB04 executes: Desktop/myDocs/programs/python/GUI/GMC_main/GMC_main.py
  The redLED pin#31 comes on, but no GUI. Still, since the redLED comes on, that shows that indeed the AutoRunAtStartup program is running,
  However while $ ps axg | grep python returns the AutoRunAtStartup.py program,
  it does not show the GMC_main.py program running.
  Pressing PB03 indeed stops the AutoRun program, as confirmed by $ ps command.
• Navigating to the GMC_main directory and executing:
  $ sudo python GMC_main.py
  in fact ran the GUI program

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