PIC16F877A RS232 running at 38400bps

[adwnis123]

I metered the voltage and it is 4,9 volt instead of 5 volt. Could this cause the strange numbers ???

Also I use capacitors of 65 Volt, 1 uF. Do I need to use less voltaged-capacitors??

Does anyone has a schematic of a MAX232 that works ???

 

[milan.rajik]

MAX232 circuit is given in MAX232 datasheet. A table also gives Capacitor values to be used.

 

[adwnis123]

MAX232 circuit is given in MAX232 datasheet. A table also gives Capacitor values to be used.

I bought an RS232 to 0/5 Volt module in order to overcome the problem. I connected the Tx--->Rx in order to check if it sends the correct data.

It does not sends the correct data. I changed the baudrate to 9600 and then it sends the correct data.

As far as my major problem is concerned (that the my post belongs), could the 38400 bps be a problem for the strange numbers I get on the terminal PC, when I connect the PIC????

 

[milan.rajik]

Zip and post your complete mikroC project files. I will test it using my EasyPICv7.

 

[adwnis123]

Here it is

 

[milan.rajik]

Try this code. Don't test on breadboard. Test on a soldered board.

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Code C - [expand]
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void main()
{
    UART1_Init(38462);                 // Initialize UART module at 38400 bps
    Delay_ms(1000);                     // Wait for UART module to stabilize
 
    while(1)
    {
        UART1_Write_Text("DB7EHello World!");
        Delay_ms(1000);
    }
}

---

- - - Updated - - -

Try this code.

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Code C - [expand]
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void main() {
    
    TRISC = 0x80;
    PORTC = 0x00;
    
    UART1_Init(38462);                 // Initialize UART module at 38400 bps
    Delay_ms(200);                     // Wait for UART module to stabilize
 
    while(1) {
        UART1_Write_Text("Hello World!");
        Delay_ms(1000);
    }
}

---

 

[adwnis123]

Nothing happened!

 

[paulfjujo]

hello

try with a CR LF at the end of string

...
while(1) {
        UART1_Write_Text("Hello World!\r\n");
        Delay_ms(1000);
    }
..

or simplest test

   .... 
   while(1)
   {
        UART1_Write('H');UART1_Write('e');UART1_Write('l');UART1_Write('l');UART1_Write('o');
        UART1_Write(13);UART1_Write(10);
        Delay_ms(1000);
    }
  ..

 

[milan.rajik]

The 16F877A which I have is dead. I have ordered two new 16F877A's. I will get it in another 4 days. Wait till then. Once I get them I will test it on EasyPICv7 and report back. I also have to get 16 MHz crystal.

 

[adwnis123]

Hello! I changed the PIC with a new one and finally worked!!!! Thank you all for your help!!!!