Chris Howard wrote:
What I want to build is a little card that will
output three different sub-audible tones, 100hz,
123hz, and another similar one. I would like three
if "sub-audible" means that the human ear cant hear it then i have to
say that those frequenciey are clearly _not_ sub-audible. but it may be
that your kenwood transeiver has a band pass built in, so that it does
not transmit those low frequecies, or the receiver does filter them.
pins as input to select which tone to output,
then have the appropriate tone appear on the single
output pin. I'll be putting this into an older kenwood vhf
2meter ham radio. So I am trying to match the configuration
already indicated by the radio's wiring diagram.
...
I think maybe I want to use timerA to generate my tones?
yes, timer a or b in PWM mode is well suited to generate tones.
that way you can program the frequency in CCR0 and set CCR1 = CCR0/2 for
a symmetric square output signal. you can also add a RC lowpass at the
output to filer out the harmonics.
chris
