DS1307 RTC

[admin]

yes, you should set i2c pins first step, then your program code will use that setting as default. here is photo, just do as photo.
   

[Olsen@HuaHin]

Thank you for the clarification.
It means that I don't need to define SDA & SCL in my sketch, correct??

I see that SS in your explanation below SDA & SCL also use i2c pin 5, is not a conflict as my sketch don't find the RTC module connected.

[admin]

It means that I don't need to define SDA & SCL in my sketch, correct?? yes, just define in "pins_arduino.h".

[Olsen@HuaHin]

What about pin 5 used twice, both the SCL and below in SS in the "pins_arduini.h"

Is that not a conflict?

[admin]

yes, need use two different, i just tell you which two pins for I2C need preset.

[Olsen@HuaHin]

yes, need use two different, i just tell you which two pins for I2C need preset.

What pin to use here instead of pin 5

[admin]

A16 board, not use SPI bus, you can delete it or write any other GPIO number.