dtmf mt8870 interface with at89c2051 atmel ic

[jardine1687]

hi guys.i have a problem interfacing mt8870 to atmel ic at89c2051.. i have already made the circuit board of mt8870 basing on its datasheet circuit board and it works well..i can generate 4 (q1 to q4) logic outputs corresponding to the dtmf keypad which i press..but when this dtmf output logics is connected to my at89c2051 inputs p3.0,p3.1,p3.2,p3.3 the outputs of the dtmf mt8870 cannot generate anymore correct outputs...i dont know what the problem icheck the mt8870 and atmel board all is correct and no shorted at the board..here my schematic and assembly code..please give me some advice..tnx alot..:?

MOD: Re-Uploaded B/w Converted schematic.

 

[nandhu015]

Circuit diagram is hard to read.

Always post with white background

 

[pranam77]

Circuit diagram is hard to read. Always post with white background

Done...re-uploaded the converted cicruit. But the resolution is too low. But overall the circuit seems ok if assembled HW is perfect. May be something wrong with the coding side.

 

[jardine1687]

my atmel at89c2051 is supplied with 6 volts and dtmf mt8870 supplied with 5 volts. i connected them in common ground..can this connection affects the circuit??

 

[pranam77]

my atmel at89c2051 is supplied with 6 volts and dtmf mt8870 supplied with 5 volts. i connected them in common ground..can this connection affects the circuit??

Just curious....If you can feed the 8870 with 5 volts why cant the 2051? Generally feeding the 2051 with 6 volts is above its limits as per the datasheet reads.

 

[welove8051]

the circuit seems to be little tricky, check my circuit, just interchange with 2051

 

[jardine1687]

ok thanks bro...i'll try to make new circuit board...uhmm is there already an proteus compatible in windows 7??