In SX Microcontrollers, SX/B Compiler and SX-Key Tool, tdg8934 wrote:

OK...After going through my LED matrix program using a DS1302 RTC and trying to clean it up I have one very weird occurance. 

It seems that I must have a SEROUT command anywheres after the Start: label. It doesn't matter what pin nor legal baud rate is setup for it. Also it needs to be connected to a Serial LCD. Any defined pin in the SEROUT command can be used. BUT, I can also disconnect either the +5v or the GND and it will work. If I remove both then the program does not (e.g. remove the entire serial LCD). 

Here is what I am seeing:

The program first scrolls through the Time on the top set of the LED matrix and then it scrolls the Date on the bottom set of the LED matrix. All is correct. However, the second time it scrolls through, the Time changes from it's set time of 11:59:50 PM to 00:00:01 PM    NOT the expected 12:00:05 AM (as it takes 15 seconds to go through it's cycle). The Date also is off too. 

If I connect the RA pin and either ground or +5V (or both ground and +5v)...to the LCD display and reset power to the SX52, then all works fine meaning that the Time changes from it's initial 11:59:50 PM to 12:00:05 AM and the date is good too. 

Why does it need to have a SEROUT and LCD connected to get the updates in Time and Date to work? This doesn't make any sense. It's is almost like the LCD is sending it a signal (even though it only needs as a minimum RX and +5v (or RX and gnd) to work. 

Any ideas? I'm wondering if it is related to the INTERRUPT for the LED Display. The SEROUT was originally in place as a SENDBYTE routine. However, I can have a command such as SEROUT RA.5, T2400, 0 and it will work as long as I have the LCD connected via RX (to RA.5 or what ever pin is defined) and either ground or +5v going to the LCD. 

The SEROUT command can be pretty much anywhere's after the START: label and must have either +5v or ground and the RX pin connected to the serial LCD. 

The Time and Date does not get updated correctly if the SEROUT command is located before the START: label. 

I haven't got a clue on this one. Although I think it could be INTERRUPT related. 

I have attached the program if anyone can help. 

Thanks.

---------- End of Message ----------


You can view the post on-line at:
http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=183734

Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com

The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2007 (http://www.dotNetBB.com)