Pic capmeter

[paul]

Hi,
I was wondering if anyone knew of any links to a site which could
provide some info/pic code on building a capacitance meter using two
555 timers and a 16f874 .I'm hoping to take the time difference
between the two timers when an unknown capacitance is introduced to
the 2nd 555 timer and feed it into a pic ,do the maths and feed the
o/p via RS232 for on screen display using VB6
I've seen an example on Microchip's website AN611 but I wanted to use
555 timers as opposed to RC networks

Any help appreciated

Regards

Paul

 

[Jim Simmons]

Hi,
I was wondering if anyone knew of any links to a site which could
provide some info/pic code on building a capacitance meter using two
555 timers and a 16f874 .I'm hoping to take the time difference
between the two timers when an unknown capacitance is introduced to
the 2nd 555 timer and feed it into a pic ,do the maths and feed the
o/p via RS232 for on screen display using VB6
I've seen an example on Microchip's website AN611 but I wanted to use
555 timers as opposed to RC networks

Any help appreciated

Regards

Paul

Check out this page: http://elm-chan.org/works/cmc/report.html

Jim

 

[Robert Monsen]

Hi,
I was wondering if anyone knew of any links to a site which could
provide some info/pic code on building a capacitance meter using two
555 timers and a 16f874 .I'm hoping to take the time difference
between the two timers when an unknown capacitance is introduced to
the 2nd 555 timer and feed it into a pic ,do the maths and feed the
o/p via RS232 for on screen display using VB6
I've seen an example on Microchip's website AN611 but I wanted to use
555 timers as opposed to RC networks

Any help appreciated

Regards

Paul

You should check out the AADE capacitance/inductance meter. It uses
resonant frequencies to do the measurement, and works pretty well.

He gives a schematic for the meter. You'll have to write the software
for the PIC.

Regards,
Bob Monsen

 

[Fhyndoh]

http://members.cox.net/berniekm/super.html

you don't even need the 555's! and it does a load of other stuff too