Custom ATMEGA32U4 board: using ports PB0 & PD5 (nomally RXLED & TXLED)

Other Hardware Hardware Development
1

Hi,

I'm designing a basic board based on the Arduino Micro.

On the micro, ports PB0 & PD5 are connected to an LED each, and are labelled RXLED & TXLED. These LEDs flash during RX or TX activity. I don't really care about showing TX & RX activity on LEDs - I would rather have a couple more GPIO ports.

I was wondering how I would go about disabling this current behaviour. Once the port is not toggled by serial activity, I'm guessing I can access the port using 'direct port manipulation'

How deep do I have to go to modify this?!

Cheers

Chendy

2

You can use the MISO, MOSI and SCLK. The RX and TX led might cause troubles.
http://arduino.cc/en/pmwiki.php?n=Hacking/PinMapping32u4

See also this: Problem with SS pin Arduino Micro - Installation & Troubleshooting - Arduino Forum
At the end of that thread is a solution, but you have to change the Arduino files. When you update to a new Arduino, and you forget that, it won't work anymore.