Is there a good replacement for TimerOne?

[Delta_G]

You'll also need the library from this post to get the interrupt to attach:

RA4M1 Interrupts

After looking at @susan-parker 's solution I was inspired to do something similar. On the previously linked RTC thread, I used this code to allow me to hijack the rtc carry interrupt in a similar way to what she had done with the pin change interrupt. Thus I can attach event link interrupts without needing to change any core code. The only issue is that it has to include the RTC code to work, even if you're using it for something else. I figure I'll probably want to do that again so I pulled…