Navtex Receiver

[santamaria]

I start to built a navtex receiver with 16f876.i found on net sample code but it is in assembly and i can't understand what happends there.With little asm code that i can undestand i found that working with capture module to find if the sitor bits is 1 or 0 ,also he enables timer0 for taking 10 samples per sitor bits pwm etc.I can't understand how the interrupt is working and how to decode the navtex signal.I don't care about serial input or output or how to drive the lcd(i have made working code for lcd).below i have the code and if someone can explain me what he is doing there to start built the code or if it is possible to add the assembly code for reception and then put my code there but i don't know how to work with variables in assembly and pbp.

thanks

[skimask]

That's only 40+ pages of assembly code...bit-banged serial routines, bit-banged LCD routines, and so on and so on...
I think it's time to put it in the round file and start from scratch...

[santamaria]

thanks skimast for your reply. I know how many pages are and thats why i am comfused with the program(think also that i don't know assembly).don't give me code only the steps to start building it. take out lcd and serial commands. I can't understand also when the timer0 start.after capture interrupt? and also the receiver character is not ASCII he convert it but can't translate how.

[santamaria]

when i compile the code with mplab and download it to the chip the chip doen't start. i measure with osciloscope the crystal and seems doesn't start.i face again this kind of problem and it was define different crystal value than i had in breadboard(in PBP).i am using 8 MHz crystal which working (i test it )and also i put in program that local is 8Mhz.i don't know how i can define in assembly that i am working with 8MHz crystal?

thanks

[JD123]

Set config to HS oscilator type. Aslo, using an o-scope probe on a crytal may load the crystal to the point where it quits. Use a spare port and slap it around to see if the PIC is running.

[santamaria]

I did it but the programm is not running .I will also check with XT configuration.Is it possible to define the crystal frequency in assembly as we do in PBP.?