ONE WIRE & Oscillator Frequency

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- 10th February 2008, 08:27
Bill Legge

ONE WIRE & Oscillator Frequency

I'm using:

PIC16F877A, DS1820 One-wire digital thermometer (with pull-up), readout on LCD and PBP compiler.

1. With a 4 MHz Xtal all is fine and I get accurate temperatures.

2. Change to 20 MHz and use DEFINE OSC 20 and it won't work? The compiler is getting the DEFINE OSC 20 all right as the LCD works Ok.

3. I've used other functions at 20 MHz (RS232, I2C etc) and they have been OK but the OWIN OWOUT don't want to play.

Any ideas?

Thanks. Bill Legge
- 10th February 2008, 08:59
skimask

Quote:

Originally Posted by Bill Legge

2. Change to 20 MHz and use DEFINE OSC 20 and it won't work? The compiler is getting the DEFINE OSC 20 all right as the LCD works Ok.
Thanks. Bill Legge

This might help:

http://www.picbasic.co.uk/forum/show...ighlight=owout

Actually, as long as you are using PBP 2.50, I think it WILL fix your problem.
- 10th February 2008, 11:17
Bill Legge

Ow Osc Problem

Thanks very much for the solution. I'm a month into using the PIC & PBP and running into a brick wall is depressing.

Regards Bill Legge
- 10th February 2008, 11:30
skimask

Quote:

Originally Posted by Bill Legge

Thanks very much for the solution. I'm a month into using the PIC & PBP and running into a brick wall is depressing.

Regards Bill Legge

Ah! Running... Brick Wall... Depressing... I get it! Ha!

Seriously... Keep checking back at melabs for updates/patches/etc. and of course here. There's a couple of other small bugs out there that I know of, and at least one that's not covered in the 2.50a patch...yet. Quite frankly, PBP is about as rock solid as there is. The average user would most likely never come across them.
- 11th February 2008, 10:54
Bill Legge

One Wire/osc

Hi,

I've just made the changee and it's workin fine @ 20 MHz. I'm amazed that someone knows their way around such a huge pile of code.

Who is this fellow?

Bill Legge
- 12th February 2008, 05:15
skimask

Quote:

Originally Posted by Bill Legge

Hi,
I've just made the changee and it's workin fine @ 20 MHz. I'm amazed that someone knows their way around such a huge pile of code.
Who is this fellow?
Bill Legge

It's just stuff that gets picked up along the way, and somebody happens to remember it from time to time. It's not witch-craft, but sometimes I think it's real close...