PeterH:
ZeusDashing:
How does connecting them to a common node simplify the pulse generation?It means that you only need to generate the 30KHz signal on a single pin, which makes the logic to do that simpler. Since you now only need to modulate a single pin, it also opens up the possibility of doing it entirely in hardware.
Yes you can do that. Or you can use the timer interrupt to toggle any pin you want and in fact cycle through them in turn, say 8 pulses (or timer periods ) on / off and then 8 pulses off then move on to the next one. The code I posted toggles pin 3 but there is no need to do that if you want to do what I just suggested.
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raschemmel:
I still haven't found it
Search the 328 data sheet for COM2B1
It is on page 158, 159, 160, 161, and 424.
As AWOL said the _BV(xxx) bit is the bit value macro which is found in the arduinio definition files. It sets a bit whose bit number is given in the brackets.