pwm 18f2431

[mackrackit]

You have lost me.
Where is the file being saved? Are you meaning save the data to eeprom?

This page has several samples.
http://www.melabs.com/resources/samples.htm

[robertpeach]

sorry im quite bad at explaining, but ill try my best. ill check that site out as well thanks

basically its being saved in the thing called SRAM, if im correct. which is similar to normal ram but its for special functions. Basically its just implemented as static ram. with an address of F69H for CAP1BUFH, which is the place where "capture 1 register highbyte", the place where the measurement (period in my case) has been stored temporarily, till it is overwritten by the next measurement.

[robertpeach]

ok its easier than i thought... u can just right the file address in your calculation.... e.g. (F69H)/5

am i right... or wrong again? sorry picbasicpro should be here today for me to learn from trial and error... looking at example codes and old manuals on the internet only goes so far

[mackrackit]

From Micros web site

Static RAM or SRAM
Static Random Access Memory. Program memory you can Read/Write on the target board that does not need refreshing frequently.

Calling it SRAM is a little misleading.

In your case I think you have the idea. You are talking about program variables. Variables to be used inside the program. Not permanent storage.

You have for the 18Fs four variable sizes to pick from
bit, byte, word, long

near the begining of your code you will have something like

F69H  VAR  BYTE

Then you can use F69H as in your example.
The value will be erased at power down.

[robertpeach]

ahhh thank you, thats cleared many things up for me. my picbasic pro just arrived so ill be testing all my attempted codings now!

cheers mack

[robertpeach]

ok well these are the bare bones of my code so far... i havnt actually created the algorithm yet so i havnt actually got a proper dutycycle to put in yet. and things like config settings etc i still have yet to choose. just hope its going in the right direction

'''''''''''''''''''''''''''''''''''Assembley to collect period on cap1 cap2 and cap3''''''
asm

cap1m0 = 0101
cap1ren = 1
cap2m0 = 0101
cap2ren = 1
cap3m0 = 0101
cap3ren = 1

endasm

'''''''''''''''''''''''''''values put in var for us in calculation''''''''''''''''''

F69H VAR BYTE 'Value of period at CAP1 ready for calculation
F67H VAR BYTE 'Value of period at CAP2 ready for calculation
F65H VAR BYTE 'Value of period at CAP3 ready for calculation

''''''''''''''''''''''''''''''''''''Algorithm for finding average''''''''''''''''''''''''


'yet to write it



'''''''''''''''''''''''''''''''''''pwm output'''''''''''''''''''''''''''''''''''''''''''' '''

HPWM 1, 127, 20000

'obviously unfinished and dutycycle would not be a fixed 50%

[robertpeach]

whoops just realised the pwm output wasnt quite anything...

DutyCycle var byte 'byte being the one that is answer of algorithm when thats created
CCP1CON=0 'output of pwm pin
TRISC= $00000000

HPWM 1,DutyCycle,20000

end

hopefully that should work