Hi Mike,
No, I don't have a good source for encoders I'm afraid, but see below...
High resolution shaft encoders are to be had
http://www.bourns.com/ProductLine.aspx?name=magnetic_encoders but
they're more expensive than I care to pay (£30 upwards) I've seen
various diy techniques for radio tuning.
Probably easiest and cheapest is the use of a stepper motor in generator
mode, see http://www.webx.dk/oz2cpu/20m/encoder.htm. Bulky, but as long
as the motor generates a large enough pulse at slow speed it works.
A smaller low cost solution is now available using hall effect chips -
see http://store.makerbot.com/magnetic-rotary-encoder.html. The chips
alone are very cheap
http://uk.farnell.com/jsp/search/browse.jsp?N=2031+203959&Ntk=gensearch&Ntt=magnetic+encoder&Ntx=mode+matchallpartial.
I'm thinking of buying some AS5040
http://uk.farnell.com/ams/as5040-assu/encoder-magnetic-rotary-10bit-16ssop/dp/1630800
and button magnets and just wiring my own using 'dead bug' construction.
OH2NLT uses that approach
http://www.kolumbus.fi/juha.niinikoski/Hall_encoder/Hall_encoder.htm.
Your quad math library looks very useful for synthesiser control - I
needed 38 bit math for the SI570 chip, so will now start on a driver for
that.
I have a 2x16 LCD driver written - the PIC board came with this 2 wire
circuit http://www.rentron.com/myke1.htm. I'll publish that in another
email, it might be useful to someone.
Best regards, Bob
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