Hi,
What is the best way to check the oscillator's or the Xtal's accuracy?
Setting a Pin HIGH then LOW and startover again seems clearly not a good way of doing.
Hi,
What is the best way to check the oscillator's or the Xtal's accuracy?
Setting a Pin HIGH then LOW and startover again seems clearly not a good way of doing.
Roger
Hello, Roger
Last time I did that ( 15 days ago ...)
I used my R/C Transmitter ( 1500µs neutral )... and placed a "PULSIN" command at the other end ...
Result Was OscTune +6 and +9 @ 4 Mhz, for a couple of 16F88 in Int RC mode.
You also can use a DIL canned Oscillator and a gang of dividers ( 4040 ??? ) to get a "readable" signal period.
Alain
Last edited by Acetronics2; - 4th March 2009 at 12:28.
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Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
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IF there is the word "Problem" in your question ...
certainly the answer is " RTFM " or " RTFDataSheet " !!!
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Frequency Counter! They're cheaper than a round of drinks at the pub nowadays... (even some DVM's go to 10MHz) but don't connect directly (it'll load the oscillator)... a couple of turns of enamelled copper wire around a small jar fed back with some coax to the Frequency Counter is enough to pick up a signal.
If you must connect, always do it on OSC2 which is the drive-out pin.
Connecting an oscilloscope directly to the resonator or Xtal will allow me to check the oscillator only.
To make a nice and clean measurement of the PIC itself allowing me to fine tune it (OSCTUNE register), how should I do?
Roger
For the internal osc, just set your config option to output Fosc/4 on OSC2 and check it
with a freq counter or O-scope.
With a 4MHz internal osc, you should see a 1MHz output on OSC2 when it's spot-on 4MHz.
Thanks Bruce,
What about measuring the PIC's accuracy with an Xtal?
Roger
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