I'm using Raspberry Pi 2 Model B with Rasbian and I'm trying to manipulate the GPIO ports in C by directly accessing registers (http://www.pieter-jan.com/node/15 - reference).
I have already configured pins 5, 6, and 7 as output by setting GPFSEL 5, 6, and 7 with a value 3'b001. Initially, I determined the output voltage on the GPIO pins and verified that their values are 0V. But when I tried to set GPSET register for pin 5 to 1, I checked the voltages of the 3 GPIO pins. The pin 5 had a reading of 3.3V which is the expected behavior, but other pins also changed their value to 3.3V. I checked pin 7 also had a reading of 3.3V when I did not even set the GPSET value of the pin to 1.