Very first use of PBP (newbie!)

[GrandPa]

Rich,

"define osc 8" Is NOT changing oscillator frequency, It's just telling PBP at which frequency the oscillator is running. And most important, all defines must be in UPPERCASE when using PBP. Not 100% sure if required, but I would also try writing PORTB.0 uppercase.

BobK is right too, try adding define TRISB = %00000000. I don't exactly remember why, but I had some problem a while ago using high and low without having defined the port as an output, (but PORTB.0=1 was working fine!)

Picaxe is fantastic to learn PIC, but is missing all details related with PIC registers. When you're programming with PBP you have to read and understand the datasheet of the chip you're using. Then you will be able enjoy PBP and use all the flexibility of you're PIC.

J-P

[rjones2102]

Hi all,

thanks for your help everyone. It ended up being the setting of ANSEL and ANSELH. I added the ANSEL line and portb.0 started working. So I tried to alternate all portb pins between low and high in same block of code. Then the portb.0 through portb.5 pins didn't work but portb6 and 7 did. So I added ANSELH=0 and then they all started working.

I have learnt something. Read and understand the datasheet. This is my first experience of translating the datasheet into programming registers and now I know how important it is. It's not a PICAXE!!

So if DEFINE OSC 8 doesn't change internal osc freq, what does I wonder. I am of course, not using an external osc and the chip supports 8mhz. I will read datasheet and see if I can work it out but if I haven't posted back here by the time someone sees this, please enlighten me!

Thanks again guys

Rich

[Kamikaze47]

Check out page 64 of the datasheet. It will tell you how to set the internal oscillator frequency.

To set the oscillator to 8Mhz for example:

define osc 8
OSCON=%01110000

or 4Mhz:

define osc 4
OSCON=%01100000

*edit* Page 64 according to adobe anyway - page 62 according to the page numbers at the bottom of the pages.

[Archangel]

Hi Rich,
You picked a PIC with lots of options that differ from run of the mill, Multi config registers and the like. Hard to learn to drive in a performance car, maybe start out with a Rambler or a Fiat check your other post for answers.
JS

[rjones2102]

Cool guys, very cool. I now understand how to use the registers a lot better. Setting the osc freq makes perfect sense!

I am using the 16f886 because I used to do a lot with Picaxe and it is the chip that the 28x1 Picaxe chip is based on. I have a few of them so I am reusing.

When I was young I used to do lots of handbrake turns and all sorts of crazy stuff. Whilst I'm sure I am lucky to still be alive, I really believe it has made me a better driver!

Thanks again

Rich