Hi,
i have interfaced ADC0808 with AT89c51 and i m surprised to see the IN0 pin of ADC shows 2.5V. I have not connected any sensor to it.
I like to know whether it usually shows this voltage or is there any problem with my circuit.
Moreover i see the digital values toggling randomly from 0-255 and if i ground that pin it shows 114.
can anybody help me rectifying this problem.
None of this has anything to do with Keil software tools or products... http://www.keil.com/forum/
"i'm surprised to see the IN0 pin of ADC shows 2.5V. I have not connected any sensor to it"
How does it "show" 2.5V? How have you determined that?
It's not particularly surprising for an unconnected input to show any arbitrary value - it could be due to noise, leakages, deliberate bias, etc, etc.
You would need to show your circuit diagram for any meaningful comment!
Thanks Andy for ur kind reply