Instability of microcontroller in a circuit

[nvd]

I have designed a microcontroller based circuit. Now I am done with soldering the components to a strip board. But the controller has become unstable. It hangs up occasionally. I have grounded the body of the crystal (11.0592 MHz). I am using two 30pF capacitors with the crystal. Everything works fine on the bread board. I think tha t there is an interference problem. Please guide me in this regard.

 

[nandhu015]

Re: Instability

hi

Please provide full details

what you are trying to do
which mc you are using

how do you decide mc is hanging or instable?

what about reset circuit?

regards
Nandhu

 

[nvd]

Re: Instability

I am using AT89S52. It is connected to LCD, RTC and ADC. The display (LCD) updates the inputs from RTC and ADC (analog to digital). But after runnig a while, the controller crashes.

 

[blueroomelectronics]

Instability

0.1uf caps should be placed near all VDD and VSS pins.

 

[nandhu015]

Re: Instability

Ok

if you are using interrupts
check the interrupt part of your programming.

if you are using assembly check out the stack

by the way which language are you using c or asm?

check out for dry solders

regards
nandhu

 

[nvd]

Re: Instability

Can you tell me about the type of the 0.1 uF capacitors? Why can the electrolytic capacitors be not used? Can you show that schematically?

 

[blueroomelectronics]

Instability

Large electrolytics are for filtering and necessary, the small 0.1ufs are for digital noise and also necessary.
All the kits on my site have both, look through the .pdf files of any of the kits there. The Inchworm is a good example.