Tuesday, September 14, 2010

VHF FM transmiter... PLL LCD callsign

I make no absolute question in having my callsign displayed in the LCD of the PLL, first because it wasn't me who had the hard work making the software and credit must be given to the one (PY2EAJ) who did it and second just because all I want is it to work!
Anyhow Euclides (PY2EAJ) was kind enough to provide us (me and CT5JZX) the software sources, so, I ,had some time and exercised a little of my knowledge in assembly (I only programed so far the x86 family, and a long time ago). Since assembly languages are all similar, on to the business of replacing Euclides callsign for mine.
Initialy I translate Euclides callsign to Hex and then searched for the occurrence of it, which gave me the following code:

;; 197 : hd44780="P" hd44780="U" hd44780="2" hd44780="X"
movlw H'50'
call _11498__vector
movlw H'55'
call _11498__vector
movlw H'32'
call _11498__vector
movlw H'58'
call _11498__vector

;; 198 : hd44780="J" hd44780="E" hd44780=" " hd44780="R" hd44780="X"
movlw H'4A'
call _11498__vector
movlw H'45'

Euclides hex callsign is: 50 55 32 58 4A 45
Them I replaced for my own call in Hex (see the movlw instruction):

;; 197 : hd44780="C" hd44780="T" hd44780="2" hd44780="G"
movlw H'43'
call _11498__vector
movlw H'54'
call _11498__vector
movlw H'32'
call _11498__vector
movlw H'47'
call _11498__vector

;; 198 : hd44780="Q" hd44780="V" hd44780=" " hd44780="R" hd44780="X"
movlw H'51'
call _11498__vector
movlw H'56'
call _11498__vector

Well, that is it....for now... but we still need to generate new "hex" for the pic. That's easy in Linux just issue the following command:

gpasm lc72131-ct2gqv.asm

Where lc72131-ct2gqv.asm is the changed source file

Then you get for free the following files :)


We only need the "hex" one. Now let's clean the PIC "internals":

picprog --pic /dev/ttyS1 --erase --burn

And burn the new code in it:

picprog --input-hexfile lc72131-ct2gqv.hex --pic /dev/ttyS1 --burn

No errors? Nice! I ended up with this on the display:

....We asked the wrong code to Euclides, should have been the transmit one and not the rx with 10.7 offset.....

p.s. Euclides was kind enough to send the tx code and also his new transceiver design based on the MC3362 and the LC72131 PLL. I've got mine almost finish but will send it to Pedro (CT5JZX) maybe he will test, he has a MC3362 for testing.


Kenn Goodson said...

Hello Ricardo!

Do you still have the source code from Euclides? I've been toying with the idea of porting the source to AVR but Euclides website hasn't been answering lately and I never received a response to an email I sent him.

Many thanks,


Ricardo - CT2GQV said...

Hello Kenn,

I think I have some files including source.
Can't find your email, drop me one on: mycallsign at hotmail.com