PIC18F4620 Using the Internal Oscillator

Greetings,

I have been playing around with the PIC18F4620 and have started to pour over the datasheet (daunting task). It says that it has a very good internal oscillator. Up until now I have been using a 4MHz external oscillator as that is what I have done so far and it works. But it seems to me there are big advantages in using the internal oscillator with this chip and running it much faster than 4MHz.

Has anyone got any good advice on what I should be doing to use the internal oscillator correctly in this chip, or just PIC's generally? Is there any tricks I should be watching out for?

Also Melanie showed me how to output a Decimal String by putting a # in front of the variable tone i.e. Serout 0, 6, [$1b, $52, 1, #tone]
Can you output a hex or binary value instead and how do you do this?

I am using MiroCode Studio and meProg

Cheers Bruce

To use the internal oscillator and 4x PLL w/4620/2620 for 32 Mhz you need those defines:

DEFINE OSC 32
OSCCON = %11110000 '8 Mhz, internal osc
OSCTUNE = %11000000 '4x PLL enabled

You can then use PORT on RA7 and will be able to choose to have clock out or PORT on RA6, by setting the correct config bit. I'm personally setting this with the programmer software (WINPIC from www.qsl.net/dl4yhf).

J-P

(BTW this is documented in the datasheet)

Quote:

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Originally Posted by kiwipiper

Also Melanie showed me how to output a Decimal String by putting a # in front of the variable tone i.e. Serout 0, 6, [$1b, $52, 1, #tone]
Can you output a hex or binary value instead and how do you do this?

I am using MiroCode Studio and meProg

Cheers Bruce

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Hi Bruce,
I am not sure if this works with serout, but it does with SEROUT2, HSEROUT:
BIN, HEX, DEC.

from PBP manual Sec. 5.74 :
"1) A string constant is output as a literal string of characters.
2) A numeric value (either a variable or a constant) will send the corresponding ASCII character. Most notably, 13 is carriage return and 10 is line feed.
3) A numeric value preceded by BIN will send the ASCII representation of its binary value. For example, if B0 = 8, then BIN B0 (or BIN 8) will send "1000".
4) A numeric value preceded by DEC will send the ASCII representation of its decimal value. For example, if B0 = 123, then DEC B0 (or DEC 123) will send "123".
5) A numeric value preceded by HEX will send the ASCII representation of its hexadecimal value. For example, if B0 = 254, then HEX B0 (or HEX 254) will send "FE".
6) REP followed by a character and count will repeat the character, count time. For example, REP A0"\4 will send "0000".
7) STR followed by a byte array variable and optional count will send a string of characters. The string length is determined by the count or when a 0 character is encountered in the string.

BIN, DEC, and HEX may be preceded or followed by several optional parameters. If any of them are preceded by an I (for indicated), the output will be preceded by either a "%" , "#" , or "$" to indicate the following value is binary, decimal, or hexadecimal."

http://www.melabs.com/resources/pbpmanual/
JS

Greetings Joe,

Things are never simple with these PIC's (I suppose that is the challenge). BIN, HEX and DEC do not work with SEROUT you get a compile error. So I have changed to using SEROUT2 instead. A bit of trial and error to get it to use the right baud rate but everything now working again with added features thanks to SEROUT2

Cheers Bruce