How to generate the 18kHz sqaure wave using 8051
Easy: just toggle a port pin once every 28ms!
28uS :-)
Actually, 28us !! ;-)
even easier: use the PCA of course, if you insist on using some antique or 'simple' chip, that does not apply
Erik
reference: The PCA cookbook www.intel.com/.../270609.htm
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