user1323: In a project, I’m using an EIA485 bus to send encrypted data packets. That works with Arduino’s buffered serial, but it is kind of awkward, and I’m using none of the more complex stuff in that class anyway.
If I do not use Serial anywhere in my Arduino sketch, is it safe to create my own interrupt handlers for USART_RXC etc. and to directly manipulate the USART registers?

user368: Absolutely. The only interrupt that Arduino takes for itself unilaterally is the timer 0 overflow interrupt, used for timing purposes (delay(), milliseconds(), et alia).

1323: <p>In a project, I’m using an EIA485 bus to send encrypted data packets. That works with Arduino’s buffered serial, but it is kind of awkward, and I’m using none of the more complex stuff in that class anyway.</p>

<p>If I do not use <code>Serial</code> anywhere in my Arduino sketch, is it safe to create my own interrupt handlers for <code>USART_RXC</code> etc. and to directly manipulate the USART registers?</p>
 368: <p>Absolutely. The only interrupt that Arduino takes for itself unilaterally is the timer 0 overflow interrupt, used for timing purposes (<code>delay()</code>, <code>milliseconds()</code>, et alia).</p>
