level-indicator.txt

The level indicators to be used in this project are mainly 4 wires : FULL, HALF, QTR, VCC.

REF is reference voltage which helps to detect the level. The other 3 are the level indicators and VCC is the supply voltage. 

--- WORKING ---
The VCC wire will be at the most bottom of the container. The FULL,HALF,QTR wires will be at the corresponding positions on the container.
The other end of VCC wire is connected to 5V of the arduino, and other ends of FULL, HALF, QTR is connected to ANALOG READ pins of arduino.
Also the FULL,HALF,QTR are connected to pull up resistors(resistors to the GND) to convert the correspoding changes in current to voltage.

CASE-1 : 
        When the container is full, the 5V is available at all of the FULL, HALF, QTR wires. So a HIGH is available at all the indicators
        and this is compared to the REF voltage. So a full level is sensed. (FULL HALF QTR > REF voltage)
       
CASE-2 : 
        When the container is half, the 5V is available at HALF, QTR wires. So a HIGH is available at 2 of the indicators
        and this is compared to the REF voltage. So a half level is sensed. (The FULL pin gets < REF voltage)
        
CASE-3 :
        When the container is half, the 5V is available at QTR wire only. So a HIGH is available at QTR indicator
        and this is compared to the REF voltage. So a quater level is sensed. (The FULL and HALF pin gets < REF voltage)