weird working: timer1!!!

ferkar · Joined: 14 Jul 2007 Posts: 38

hi everyone.

I had a difficult situation that i could not comment on it.

I have some program codes that uses only LCD subfunction and transmitting some values through the serial port.

I am using timer1 interrupt to generate 100ms period, that is 10*100ms =1second. Then after every 1 sec pin_a5 changes its state.

Here is the problem :
The parts of my codes are working except the part that is related to timer1. The output LED (connected to pin_a5) sometimes work properly but mostly it is not.

A strange thing: if I disconnect the supply voltage for a while then connect it sometimes cause to run properly.
(note the code works on simulation program properly)

Thanks...

ckielstra · Joined: 18 Mar 2004 Posts: 3680 Location: The Netherlands

Without more information it is impossible to say what causes your problem.

Try starting with a simple as possible program, for example blinking a led. If this works you know your hardware is correct.
Then add a module and test again. Continue adding functionality until it stops working, then you know the last added code is (part) of the problem.

Just a wild guess is that your program contains not-initialised variables. At power up the RAM memory contains random data and this may be the reason you see the program sometimes work and other times fail.