Digital Pin Set ON will have a +5 volts , with a meter you should read 4.8 - 5 volts . 7 volts for a digital pin is a bit high. What voltages were your regulators putting out at that time?

I haven't placed any voltage regulator in the place of LM1084.. The other regulator is left as it is... What am I supposed to do?

Test what voltage the regulator is putting out right now. It seems ver high. Is the led on the Bluetooth and main power led coming on?

Yeah both the LEDs are on, I'm even able to connect to the ARC. I checked each of the pins by Set Digital option, switching on and switching off. I read the voltage across each of the Digital pins and Gnd. When it is On, the value is 7.1-7.2V and when it is Off, it's 0-0.1V...

Ok check the voltage from that regulator because 7 volts is way too high , it appears that the regulator is malfunctioning and putting 7 volts in.

I haven't connected any regulator... Moreover, dosen't the voltage to the Digital pins come from the Microcontroller? I want to know about it... I don't really know if that voltage appears from the microcontroller or the voltage regulator. There is no voltage regulator connected in the place of LM1084. I trimmed it away so that I can add a new one... An LM1085...

The microcontroller does not generate the voltage it just passes through the controller from the regulator. If the regulator is putting out voltage too high the digital pin voltage could be affected. The controller is just acting as a fast on / off switch when you use the Set digital on or off feature.

Ohhhk.. But how would there be any voltage generated at the Digital pin i.e. the signal pin..