The Basic Equalizer source code is very simple because there are no concurrent or real time operations to perform. The main program loop reads the voltage on the six battery taps and calculates the single cell battery by successive subtractions. The single cell cut off voltage (set at the start of the operations) is stored in the eeprom memory for successive discharge easy restart.
The interrupt routine is only a timer for cyclical battery voltage conversion in digital, but the code could also work with no interrupt because the operations can be performed in a sequence without concurrent interactions.
The display shows the cell voltage and the cut off setting using a very simple set of routines. The theory of operations is the following:

1. The user starts the discharge with the "start key".
2. The user can modify the threshold (with select key) or wait for start of discharge.
3. The discharge on all the cells is started and each led signals the discharge of the individual cell.
4. When the cell reaches the cut off voltage the led shuts off and the cell wait for the end of discharge of the other cells (battery recovery time).
5. The cells that have more charge stored are the last to end the discharge.
6. The single cycle of discharge finish when all the leds are off (all the cells have reached the cut off voltage).
7. The single cycle discharge is repeated 10 times in order to extract all the charge from the cells, and the last cycles are very shorts and about "simultaneous": all the cells starts and ends the discharge at the same time to signal that the battery pack is completely equalized.