That's exactly why I asked -- I was wondering what kind of stray capacitance there was from the solderless breadboard. I've never been able to use a crystal on the solderless breadboard I have here.I think the bread board is adding about 85pf the cap was a 22 that I use with my crystals there supposed to be 1% caps
Not on a solderless breadboard any wayAlso shouldnt you be able to zero it out
1 & 2: Ok will do and remove the buttonThe board is looking good Atom! This is fun.
I still have some suggestions (haha);
1. adding another trimpot to let the user do global calibration is a good idea. Please see what i said in post #17.
2. The button on PCB may be under the LCD? I still think the button is better OFF the PCB as they can position it nice on front panel. Then the space on PCB can be used for that 2nd trimpot.
3. Does it really need the ICSP connector? With through hole they/you can program the PIC and plug it in a socket. Removing ICSP connector makes the PCB simpler and smaller and probably makes routing easier.
I just measured two adjacent empty rows on a solderless breadboard (5holes/row) and they measured 3.1pF. Much less than I expected! Maybe it is double that or more depending what is on each side of a row (what is plugged in).
In the past when I have used xtals in breadboards I left out the 22pF caps and it always worked ok.
Burt, did you remove the link for the video? I can't see it on this page but maybe it's my clunky old web browser...
(edit) Can that last statement I had Flash turned off in my browser. I was able to see your vid from the url; http://www.youtube.com/watch?v=9FZDP-8Osyk
If that 107pF is the base reading (ie C1 and all the wires etc) you can zero it out by pressing the zero button (or short PIC pin RB2 to GND).
Bread board not much good for a cap meter it doesn't read them right I'll post my finished one this weekend I have a nice box for this.If that 107pF is the base reading (ie C1 and all the wires etc) you can zero it out by pressing the zero button (or short PIC pin RB2 to GND).