For 8051 & Keil C51 programmers ?

[SphinX]

Salam,

My main function update always a lcd display with message1.
There is external interrupt to detect if a card is detected.
If a card is detected, then disable all interrupts, clear the lcd and display message2 for 2 seconds.

The problem, when it return from interrupt to the main function to continue update the lcd with message1, i notice there strange characters appear on the lcd display !!!

What is the solution ?

Thanks

 

[C-Man]

shannings post is very useful for you :-(

I think your problem is that the interrupt can be anywhere while you print message1 even in the middle (if you are using 4 bit mode) of a character.

Best solution is to only set a flag when your interrupt occurs and do the rest in the routine where you print message1.

hope this helps

 

[SphinX]

Salam,

shanning wrote,

Good Luck!

It's very usefull solution thanks very very much hahahaha

C-Man wrote,

I think your problem is that the interrupt can be anywhere while you print message1 even in the middle (if you are using 4 bit mode) of a character.

Thanks C-Man that i guess too.

C-Man wrote,

Best solution is to only set a flag when your interrupt occurs and do the rest in the routine where you print message1.

I will try it and tell you the results, and if there are any other solutions will be welcome.

SphinX

 

[nex]

Re: For 8051 & ke*il C51 programmers ?

Salam,
The problem, when it return from interrupt to the main function to continue update the lcd with message1, i notice there strange characters appear on the lcd display !!!
Thanks

Hi,

How about clearing the display at the end of interrupt ?

Cheers !

 

[petarpav]

For 8051 & ke*il C51 programmers ?

Hi. Look at your ISR do you save and restore all changed registers.

Best Regards.