[SOLVED] Problem of Max232 and 89C51 simulation Proteus (have project file)

[thanhmssl10]

(Have Project file below)

Like tile, I have some problem with Circiut have max232 and 89C51, transfer data over COM port (Simulation by Proteus 7.8 SP2 and Virtual Serial Port Driver 7.2 Trial)

According to circuit I saw at internet, pin 2 of COM connect to pin 14 of max232 and 3-13
(Rx-T1OUT , Tx-R1IN)
and Max232 to AT89C51 is 11 -11 and 12 - 10

But If I do that, I 89C51 can't received any data from max232 (from pin 10)
If I connect Rx of COM to R1IN of Max232 (2-13), at pin 10 of Max232 have data ( I use Virtual Terminal)

And when i send data from a program vb6 to com port, Rx pin was Red.

This is my Project file: View attachment Max232_89C51_COM_Proteus_7_8.zip
Plz help me!
I'm noob in Circuit, please help me!

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Please see my circuit and my code of IC 89C51 ( write by ASM), help me find out my error

 

[Easyrider83]

Pin 2&3 of COM connector mixed. Grey state means floating input. Orange mean logic contension.

 

[milan.rajik]

If you are simulating Serial COMM in Proteus then don't use MAX232. Just connect TxD of COMPIM to Tx of MCU and RxD of COMPIM to Rx of MCU. Set baudrate for COMPIM and VT.

 

[thanhmssl10]

Thank you so much, I do like that and It's work, but i want to know why when simulation, max232 not work

 

[milan.rajik]

MAX232 inverts data. If you add 2 NOT gates for Tx and Rx between MCU and MAX232 then it will work.

 

[thanhmssl10]

Aha!, now, i knew why when I put Virtual terminal after max232, It show wrong data, and when I choose "Invert" in menu of virtual terminal, It show true data. Thank for help