ATMega 328 unused inputs

Hardware
1

Is it possible to connect to the unused analog pins of the ATmega328?
On the hardware wiki it lists:
Analog 3
Analog 4
Analog 5
Analog 7
As unused. If I wanted to add something to those and update the sketch of the ATmega through a USB to UART, where would I solder to those analog points?

Also, would adding other sensors inline with the LCD by unplugging the jumpers and soldering together a 3-way parallel jumper wire be able to work without messing up the I2C programming that the ATmega handles for 2 seconds and that the raspberry pi takes over?

Thanks
Daniel

2

I have moved the above post to a new thread, as it appears to have little or no connection to the matters being discussed in the original thread.

Do I take it that you are referring specifically to the '328 in the emonPi?

If you are, I suggest you download the Eagle CAD files: GitHub - openenergymonitor/emonpi: Raspberry Pi Based Energy Monitor. Hardware, Firmware & related software for the PI.
and study those. IIRC, the unused inputs are not brought out beyond the device pins, so that is where you must solder on - and that is hardly practical. Note though that ADC4 & 5 are multi-purpose pins, and are used as SDA & SCL to the LCD display.