Trouble while sending data from PC to PIC16F887 via MAX232

[allymak]

Hello everyone, sorry for eventually bad english lol

I'm tryna simulate an Proteus circuit that could send data from any PC with RS232 interface to PIC16F887, which chip uses TTL language. I did the data flow from PIC to PC, but`s not working vice-versa. In simulation, I put two Virtual Terminal, each one in both sides of communication (TTL and RS-232), using the MAX232 chip, to read the data flow. The one which represents the receiving data is set to Inverted mode because of the inverted data in the RS232 side of MAX232. Each command sent from any sides should return a message of acknowlegdement (ACK).

I saw many examples of creating the circuit in Proteus, including capacitors` values, they are the same way, so i think the problem should be any configuration from the code, or even the simulator.

I'm working with an Pascal (MikroPascal) compiler, but i know that many people working with PIC uses C, so I kindly accept answers with any code language at least to confirm is the circuit is properly assembled.

the section of the circuit of interest in Proteus
https://ibb.co/0tCmQkj

circuit working only from PIC to PC
https://ibb.co/NSqgyNw

thank you for the attention and have a nice day [/url]
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[temtronic]

The PIC's UART only has a 2 character buffer,so if your PC sends more characters before the PIC can process them ( read the UART buffer ) then the UART will 'overrun' and 'locks up', 'freezes'.
In CCS C , you add 'ERRORS' to the options when setting up the 'RS232' serial communications. This tells the compiler to add code to handle the 'overrun' condition.
Normally with any serial communications, you receive data into a 'buffer' using an Interrupt Service Routine(ISR). Whenever a character is sent to the PIC, the ISR 'sees' this action , reads the UART incoming data,saves the data in a circular buffer and sets a 'flag'. Your 'main' program then 'sees' this flag and read the data from the circular buffer and does 'something with it(say display on LCD module).
Normally the circular buffer will be 2x longer than the 'data stream' you expect to get. If you expect 'Hello PIC' from the PC, then you'd create a buffer of 20 characters long. The longer the buffer the more time you have to process the data.

Hopefully this will help you.....

[dyeatman]

Therein lies the problem with using Proteus and why we say NOT to use it...
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