Arduino Uno uploading technique Need some INFO


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.

If you want to use the RX/TX lines from the Uno board to your mega168, then you will need to:

1) remove the mega328P from the Uno board, so it doesn't conflict.


2) keep the mega328P in reset mode, so it doesn't conflict. Jumper the reset pin to GND.

Yup, I will be removing the mega from the board. That was the plan.

isnt it short RESET to +5v to disable REST?

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.