Timer 1 Arduino - Create 2 Timers
The Timer1 library only supports... Timer&nbsp;1! So you only have one
hardware timer available. If you are using an Arduino Uno or anything
similar, you have a couple of other timers. However, unlike
Timer&nbsp;1, which is a 16-bit timer, the others are 8-bit only. This
means they are very limited in the range and precision of the
frequencies they can generate. If you have an Arduino Mega, then you
have a few other 16-bit timers available. You may want to search for a
library called Timer3, which should work just like Timer1, while using
the 16-bit Timer&nbsp;3.

If you don't find any suitable library, you may still be able to
generate your two signals using only Timer&nbsp;1. Here is the trick:


set both PWM outputs to “toggle on compare match”
enable both compare match interrupts
in each of these ISRs, advance the compare match register by half a
period of the corresponding signal.


For doing this you will need to dig into the low-level details of how a
timer actually works. I recommend you start by reading the
Timers and counters tutorial by Nick Gammon.
Take the time to read and
study this. It's not a topic you will be able to master in just a
couple of hours.