Quick question when uploading a program to the Ardunio Uno or any Ardunio the data is routed through the RX/TX lines to the MCU. The reason I am asking I am trying to hook my Atmega168 to my Uno board so I can program it. The Atmega 168 already has a bootloader on it.
The RESET is an active low signal. Meaning you pull it down to 0v to make it active. This will keep the mega328P in reset mode, so the i/o pins will not be active. This is only if he keeps the mega328P in the Uno.