Crystal Signal? Where is it???

[Sharky]

Hi Netjammer,

I think that I misunderstood your question. I thought that the problem was that your program would not execute.
Are you trying to messure directly on the crystal?

Regards
Sharky

[Netjammer]

Hi Netjammer,

I think that I misunderstood your question. I thought that the problem was that your program would not execute.
Are you trying to messure directly on the crystal?

Regards
Sharky

Hi Sharky,
I'm measuring on the actual pins (13/14) with an O-scope probe. Please see my latest response, the 16F877 that has the temp code loaded has a clock signal on Pin 14 but not on 13. I'm trying to find the original code that I loaded to see if there is an INCLUDE or DEFINE that causes this.

Thanks again!
Netjammer-

[Darrel Taylor]

I see in your picture you are using an ATS040 crystal.

That is an AT Strip Cut type crystal, and may need to have a series resistor.

See Figure 12-1 in the 877 datasheet.

Just another possibility,
Darrel

[Dave]

Sharky, When you are probing the osc. pin 13 can you confirm that the code is running? Pin 13 is the osc. input and you could be loading it down with the scope probe. This will stop the crystal from oscillating and the micro pin will look as if there is no activity. Taking the probe off, the oscillator will then start again. Probing the oscillator output pin, There is enough drive to overcome the added capacitance of the probe.

Dave Purola,
N8NTA

[Sharky]

Hi Dave,

I'm not the one that is trying to messure on pin 13

Well I agree on that you could stop the oscillator with your scope prope,
that's why I asked Netjammer if he was messuring directly on the osc pins.

I don't know the LAB X1 board, but when I read about it, it says that it has a crystal oscillator that can be set to different frequencies.

So as you say Dave you can not messure directly on the pins when using a crystal and 2 caps hooked up to the PIC because the capacity from the skop prope wil stop the oscillation, but it is possible to messure the output on a "extern" oscillator like the one I think is on the LAB X1 board.

Puuh, I hope you understand me english, writing is absolut not what I like most!

Regards
Sharky

[NavMicroSystems]

Netjammer,

it could also be a problem wit the breadboards capacitance.

This has been discussed several times on the forum.

search for "breadboard"

[Netjammer]

Hi Everyone, just wanted to say thanks again. I didn't get the crystal work but did use the RC capabilties and the microcontroller worked fine, though at a much slower clock speed. Today I purchased several crystal oscillators ranging from 5, 10, 12, 16MHz. I will give them a try. I'll post my results.

Thanks again all,
Netjammer-