Interrupt-Driven Software UART

Interrupt-Driven Software UART based on Atmel Software Framework , tested on SAM3 Cortex M3 at 57600bps

Start bit detection is managed by programmed GPIO falling edge interrupt handler,

For bit timing is used timer counter, compare interrupt handler.

Timer handler raises every 0.5 bit time periode and data sampling is managed by state machine in timer handler subroutine.

Software can be used for any pin which supports external interrupt.