I'm currently designing a project that needs UART, I2C and interrupts. I would also like the UART to be usable while leaving the possibility to flash the device without any interaction from the user.
That last requirement made me change my base arduino for my project from the nano (328p) to the micro (32u4) which has a dedicated UART. After ordering it, i realized that the micro has i2c hooked up to the int2 & 3 pin, which I need. =(
On the nano or the uno, the i2c does not need interrupt to work properly (as far as I understand the schematics of those arduino and the datasheets of those atmel chips).
Is it possible for me to compile a custom bootloader that will reassign sda and scl pins to analog ones (as I do not use them at all) like on the uno/nano ? I thought that "just" reassign pin in pins_arduino.h could be enough. Is that right ?
Or does the micro need to use interrupt to drive the i2c ? If so, do I have any other option to have i2c, hardware uart and 2 interrupt pins free (appart from keeping the nano and use an external i2c to uart bridge, which I have already considered) ?