In this series a do whirl wind tour of the Python code I developed to control my PifaceCAD raspberry pi add on board. I this use to control a music player running on a remote raspberry pi upstairs.

In this episode I cover my use of global variables.

List of global variables along with associated comments explaining what they are used for

# GLOBAL VARIABLES

RemoteDevice = "[email protected]"

# Username and ip address of the remote device to control

SeekMin = -6

# Sets the minimum value of the variable SeekPosition

SeekMax = 6

# Sets the maximum value of the variable SeekPosition

SeekPosition = 0

# stores seek menu position,

SeekMenu = False

# used to track seek menu state, ie are we in seek menu or not

FirstPass = True

# Used to track 1st time button 5 (backlight toggle) is pushed, turns off blinkstick

LcdLightOn = False

# used to track toggle sate of backlight button 5

MenuMin = 0

# Sets the minimum value of variable "Menu"

MenuMax = 2

# Sets the maximum value of variable "Menu"

Menu = 0

# global variable used to keep trak of selected menu

IrActive = False

# used to track toggle state of active infrared buttons, when false disables

# all buttons on the remote control except the blue button.

StoredTime = 0

# Stores curent time in seconds when a button is pushed, used by double button tap feature

#GET_IP_CMD = "hostname –all-ip-addresses"

# Debian 7 wheezy, Command to get IP adress

GET_IP_CMD = "hostname --all-ip-addresses | cut -d' ' -f1"

# Debian 8 jessie, Command to get IP adress

#GET_ESSID_CMD = "iwconfig wlan0 | grep 'ESSID:' | cut -d':' -f2"

# Debian 7 wheezy, Command to get wifi ESSID

GET_ESSID_CMD = "/sbin/iwconfig wlan0 | grep 'ESSID:' | cut -d':' -f2"

# Debian 8 wheezy, Command to get wifi ESSID

GET_WIFI_STRENGTH_CMD = "/sbin/iwconfig wlan0 | grep 'Link Quality=' | awk '{ print $2 }'"

# Command to get wifi signal strength