Pre paid energy meter with Arduino and GSM sim 800C recharge and "pulsein" counting problem

[6v6gt]

For debugging, I'd suggest moving the GSM module away from the standard RX and TX and use two of the free analog pins and Software Serial instead. Alternatively, use a USBTTL device on two free analog pins. This would allow you to print debug messages, intermediate values, etc. to the serial console.