Software Serial Port problem, damages pic18f4550

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I am using PIC18F4550 Micro-controller for interfacing it with three serial port devices.

It has to collect data from two devices and then send data to a device.

I am using two software uart and one hardware uart, while using software uart port, one of mine max232 gets damaged and my controller RB0 gets damaged also, on which i am receiving data from the device.

It happens many times.
Does anyone had faced the similar problem.

 

[paulfjujo]

hello,

post your schematic..maybe something wrong !
it's very difgicult to destroy a PIC..
only if you apply + or - 12V from direct serial port..

 

[mrsalesi]

I try for McroC + roteus .

My pic is fine but i have "PIC18F4550 Soft_UART problem".

I don't receive any reaction whit this code and schematic. what is problem?


====================================================================
char i, error, byte_read; // Auxiliary variables

void main(){

ADCON1 |= 0x0F; // Configure AN pins as digital I/O
CMCON |= 7;

TRISB = 0x00; // Set PORTB as output (error signalization)
PORTB = 0; // No error

error = Soft_UART_Init(&PORTC, 7, 6, 9600, 0); // Initialize Soft UART at 14400 bps
if (error > 0) {
PORTB = error; // Signalize Init error
while(1) ; // Stop program
}
Delay_ms(1000);

for (i = 'z'; i >= 'A'; i--) { // Send bytes from 'z' downto 'A'
Soft_UART_Write(i);
Delay_ms(1000);
}

while(1) { // Endless loop
byte_read = Soft_UART_Read(&error); // Read byte, then test error flag
if (error) // If error was detected
PORTB = error; // signal it on PORTB
else
Soft_UART_Write(byte_read); // If error was not detected, return byte read
}
}

========================================================================
I but Proteus +MICROC below :


View attachment PIC18F4550_softwareUart.zip




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I have good result in hardware USART and other sample in microc+proteus( as same as work in real world).
so pleas help ??????????????
:idea::???::sad::evil::shock: