Detail for my cal_CT1_v_meter.ino sketch

/* cal_CT1_v_meter.ino 
 *
 * February 2018
 * This calibration sketch is based on Mk2_bothDisplays_4.ino. Its purpose is to
 * mimic the behaviour of a digital electricity meter.  
 *
 * CT1 should be clipped around one of the live cables that pass through the 
 * meter. The energy flow measured by CT1 is noted and a short pulse is generated 
 * whenever a pre-set amount of energy has been recorded (normally 3600J).  
 *
 * This stream of pulses can then be compared against optical pulses from a standard 
 * electrical utility meter. The pulse rate can be varied by adjusting the value
 * of powerCal_grid.  When the two streams of pulses are in synch, correct calibration 
 * of the CT1 channel has been achieved.