Yes, depending on the software the xtal rate could affect both serial comms and lcd display operation.

If you can't find a 4 mhz crystal quickly, let me know.

73,

Steve W5ZA Shreveport, La.

----- Original Message ----- From: "Stefano Simonetti" [email protected] To: [email protected] Sent: Saturday, August 22, 2009 5:36 PM Subject: [amsat-bb] Re: lvb tracker circuit -- xtal?

I 've read now the .c file included in the lvb distribution, I noticed that xtal frequency surely affects the baud rate.

I will find a 4 Mhz xtal, sorry for BW.

________________________________ Da: Stefano Simonetti [email protected] A: [email protected] Inviato: Sabato 22 agosto 2009, 23:45:29 Oggetto: [amsat-bb] lvb tracker circuit -- xtal?

Hi, I have problems in making the LVB tracker circuit run.

I have built the LVB tracker ver. PCB v1.2, Firmware v0.7, Programmer v0.2, Documentation v1.9, 7 Dec 2004, by G6LVB.

The firmware was flashed successfully with IC-PROG v 1.06B, a homebrewed interface for LPT, and an old PC with LPT1 running win98.

The LVB circuit requires a 4 MHz XTAL for the PIC 16F876A.

I tried with a 10MHz, and a 3,5795MHz as I haven't a 4MHz. No success. No LCD, no serial communication at all.

Does anybody know if the problem could be in having installed a different xtal (i.e.: does the firmware takes care about the frequency of the clock?)?

Regards, Stefano Simonetti (IW1RDZ) - Italy.

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Hi Stefano.

Yes, as others have stated, you need a 4MHz crystal for the serial port bit rate to be correct.

Please also use the latest .HEX file (0.9) located here: http://www.g6lvb.com/Articles/LVBTracker/LVBTrack.hex

When programming, you should use the PICPROG.EXE v0.2 program http://www.g6lvb.com/Articles/LVBTracker/PicProg.exe with the PIC in situ on the board using a hardware (not USB virtual) serial port.

If, for some reason, you choose not to use PICPROG.EXE, you can use MPLAB instead with a compatible programmer. Configure->Select Device as 16F876 or 16F876A device as appropriate, File->Import the hex file, and set Configure->Configuration bits like this:

// Default config bits... // Osc=XT, WDT off, PUT on, BOD off, LVP off, FPW on, DBG off, data EE prot off, CodeProt off au16Data[0x2007]=0x3F31;

Check first with a 'scope that the crystal is oscillating. If it's not, check the power on the chip. See if the reset button switches the the oscillator off and on.

Also please check the 9 pin D type on the PCB itself is a socket, NOT a plug! Even if you use a gender changer, it will not change the fact that if you solder a plug and not a socket to the board, the pins 1,2,3,4,5 will end up being 5,4,3,2,1 so your tracker will not work.

There is no echo from the LVB Tracker, emulating the exect function of a real GS-232A. Hitting Enter (<CR> for us oldies) from a terminal emulator should return a prompt though.

Regarding the LCD, do you get a top row of slightly dark blocks? Try checking the contrast adjustment.

73, Howard G6LVB

-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Stefano Simonetti Sent: 23 August 2009 10:40 To: [email protected] Subject: [amsat-bb] Re: lvb tracker circuit -- xtal?

Thanks to all for comments.

This evening I 'll try to re-flash PIC with the correct fuses, and try with the 3,5...MHz XTAL I have, to obtain at least LCD on.

The external flashing introduces another variable, right.

Ciao, Stefano.

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