thanks everybody for the quick replies... Its good having helping hands such as yours... well, back to biznez.... ^_^ ...
hi nikhil... I did notice that we could use a single max232 for both the phone and the 89s51... however, in my case I used separate max232 for ease of troubleshooting....
Jerin, hey there.... from ur reply do u mean that I've to add new lines to my current program? if so, I'll try to do that...
hi saeed... yes my phone communicate well with the pc's hyperterminal(I've attached the hyperterminal-phone screen shots in previous post)... and its also perform as desired with proteus simulation.... the connection when I do these experiments is
phone---->max232----> pc port----> hyperterminal/proteus
As for the 89s51, I also did an experiment with its connection.... I make a program so that the 89s51 will transmit ATD0125410400.... It did as expexcted... below is a screen shots of the command transmitted by 89s51 to hyperterminal... the connection when I do this is 89s51--->max232---->pc port--->hyperterminal
I've also tried the same program with this connection phone---->max232--->max232(again)---->89s51... here's the picture of the experiment
looks like the ATD0125410400 did arrive to the phone...hurmmm.... I think I'll try the connection U suggest too... But I want to know... how can we know the phone data is TTL? any method?
looking forward for replies from all of U... hope it will work... thanx in advance ya....