Thanks for replying, can you help me check the schematic that i have draw in proteus.There are many things make me confusing:???:.In this schematic i can send and receive from/to both side.Would you give me the explain for these:
1.Why we need an invertor in this schematic?
2.Why I can send and receive data correctly while the input of Max232 is just TTL standard.How can i get the RS232 standard to MAX232 in proteus?
3.When i put a 555 timer in the other side to control receiving and sending but this is not work? I want to use 2 555 timer to control it.
Thanks you very much.
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