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From: zheng on 10 Dec 2008 10:41
Hi all,

I am using dspic30f6010a interfacing pc with rs232.
when I use hyperterminal, I can only receive something like
<<x<<||||||üüüü. why is that? And how can I send signal from
hyperterminal.
when I use matlab, the program automatically terminates when I write:
s=serial('com1','BaudRate',9600); fopen(s)
why is that?
The pic program is as follow, anyone can help?

#define PLLODE 1
#define FCY XTFREQ*PLLODE
#define BAUDRATE 9600
#define BRGVAL ((FCY/BAUDRATE)/16)-1
char Buf[80];
char * Receiveddata = Buf;
void initU1(void)
{
U1BRG = BRGVAL; // initialize the baud rate generator
U1MODE = 0x8400; // ENable, 8data, no parity, 1 stop
U1STA = 0x0440; // enable the Transmitter
} //initU2

//This is UART1 transmit ISR
void __attribute__((__interrupt__)) _U1TXInterrupt(void)
{
IFS0bits.U1TXIF = 0;
}
//This is UART1 receive ISR
void __attribute__((__interrupt__)) _U1RXInterrupt(void) /*Declare 232
interrupt ISRs*/
{
IFS0bits.U1RXIF = 0;
//read the receive buffer till atleast one or more character can be read
while (U1STAbits.URXDA)
{
( *(Receiveddata)++) = U1RXREG;
}
}
int main (void)
{
// Datta to be transmitted
char Txdata[] = {'M','i','c','r','o','c','h','i','p'};
initU1();/* Call function to initialize */
while(1)
{
while( U1STAbits.UTXBF); // wait while Tx buffer full
U1TXREG = (unsigned int *)Txdata;
while(U1STAbits.TRMT)
( *(Receiveddata)++) = U1RXREG;
}
}


From: srl100 on 10 Dec 2008 11:46
>Hi all,
>
>I am using dspic30f6010a interfacing pc with rs232.
>when I use hyperterminal, I can only receive something like
><<x<<||||||üüüü. why is that? And how can I send signal from
>hyperterminal.
>when I use matlab, the program automatically terminates when I write:
>s=serial('com1','BaudRate',9600); fopen(s)
>why is that?
>The pic program is as follow, anyone can help?
>
>#define PLLODE 1
>#define FCY XTFREQ*PLLODE
>#define BAUDRATE 9600
>#define BRGVAL ((FCY/BAUDRATE)/16)-1
>char Buf[80];
>char * Receiveddata = Buf;
>void initU1(void)
>{
> U1BRG = BRGVAL; // initialize the baud rate generator
> U1MODE = 0x8400; // ENable, 8data, no parity, 1 stop
> U1STA = 0x0440; // enable the Transmitter
>} //initU2
>
>//This is UART1 transmit ISR
>void __attribute__((__interrupt__)) _U1TXInterrupt(void)
>{
>IFS0bits.U1TXIF = 0;
>}
>//This is UART1 receive ISR
>void __attribute__((__interrupt__)) _U1RXInterrupt(void) /*Declare 232
>interrupt ISRs*/
>{
> IFS0bits.U1RXIF = 0;
>//read the receive buffer till atleast one or more character can be read

>while (U1STAbits.URXDA)
>{
> ( *(Receiveddata)++) = U1RXREG;
>}
>}
>int main (void)
>{
>// Datta to be transmitted
>char Txdata[] = {'M','i','c','r','o','c','h','i','p'};
>initU1();/* Call function to initialize */
>while(1)
>{
> while( U1STAbits.UTXBF); // wait while Tx buffer full
> U1TXREG = (unsigned int *)Txdata;
> while(U1STAbits.TRMT)
> ( *(Receiveddata)++) = U1RXREG;
> }
>}

While I am not familiar with the dspic UART, it looks to me like you might
not be putting the *contents* of the Txdata buffer into the TXREG. I
imagine you will need something like...

char Txdata[] = {'M','i','c','r','o','c','h','i','p','\0'};
int i=0;
while(Txdata[i])
{
while( U1STAbits.UTXBF); // wait while Tx buffer full
U1TXREG = Txdata[i];
i++;
}

You also appear to be handling received data in both the main loop and an
ISR.

You also appear to have no guard for when received data overruns your RX
buffer.

From: David Brown on 10 Dec 2008 17:19
zheng wrote:
> Hi all,
>
> I am using dspic30f6010a interfacing pc with rs232.
> when I use hyperterminal, I can only receive something like
> <<x<<||||||üüüü. why is that? And how can I send signal from
> hyperterminal.

I don't want to start yet another "my terminal emulator is better than
your terminal emulator" (so please don't give more suggestions unless
the OP specifically asks for them!), but there is a wide consensus that
hyperterminal is terrible, and is often the cause of problems when
trying to do this sort of communication. Get Tera Term Pro from the
link below. It's not the most powerful or sophisticated terminal
emulator available, but it is small, free, easy-to-use, reliable, and a
standard tool for many embedded developers.

<http://hp.vector.co.jp/authors/VA002416/teraterm.html>


Of course, there are *also* bugs in your program, as "srl100" pointed
out. Tera Term won't fix them, but it *will* make your development and
testing easier, and eliminate a cause of problems and irritation.
From: zheng on 11 Dec 2008 05:00
>>Hi all,
>>
>>I am using dspic30f6010a interfacing pc with rs232.
>>when I use hyperterminal, I can only receive something like
>><<x<<||||||üüüü. why is that? And how can I send signal from
>>hyperterminal.
>>when I use matlab, the program automatically terminates when I write:
>>s=serial('com1','BaudRate',9600); fopen(s)
>>why is that?
>>The pic program is as follow, anyone can help?
>>
>>#define PLLODE 1
>>#define FCY XTFREQ*PLLODE
>>#define BAUDRATE 9600
>>#define BRGVAL ((FCY/BAUDRATE)/16)-1
>>char Buf[80];
>>char * Receiveddata = Buf;
>>void initU1(void)
>>{
>> U1BRG = BRGVAL; // initialize the baud rate generator
>> U1MODE = 0x8400; // ENable, 8data, no parity, 1 stop
>> U1STA = 0x0440; // enable the Transmitter
>>} //initU2
>>
>>//This is UART1 transmit ISR
>>void __attribute__((__interrupt__)) _U1TXInterrupt(void)
>>{
>>IFS0bits.U1TXIF = 0;
>>}
>>//This is UART1 receive ISR
>>void __attribute__((__interrupt__)) _U1RXInterrupt(void) /*Declare 232
>>interrupt ISRs*/
>>{
>> IFS0bits.U1RXIF = 0;
>>//read the receive buffer till atleast one or more character can be
read
>
>>while (U1STAbits.URXDA)
>>{
>> ( *(Receiveddata)++) = U1RXREG;
>>}
>>}
>>int main (void)
>>{
>>// Datta to be transmitted
>>char Txdata[] = {'M','i','c','r','o','c','h','i','p'};
>>initU1();/* Call function to initialize */
>>while(1)
>>{
>> while( U1STAbits.UTXBF); // wait while Tx buffer full
>> U1TXREG = (unsigned int *)Txdata;
>> while(U1STAbits.TRMT)
>> ( *(Receiveddata)++) = U1RXREG;
>> }
>>}
>
>While I am not familiar with the dspic UART, it looks to me like you
might
>not be putting the *contents* of the Txdata buffer into the TXREG. I
>imagine you will need something like...
>
> char Txdata[] = {'M','i','c','r','o','c','h','i','p','\0'};
> int i=0;
> while(Txdata[i])
> {
> while( U1STAbits.UTXBF); // wait while Tx buffer full
> U1TXREG = Txdata[i];
> i++;
> }
>
>You also appear to be handling received data in both the main loop and
an
>ISR.
>
>You also appear to have no guard for when received data overruns your RX
>buffer.
>
>
Hi, thanks for your suggestion.
I tried just send a signal char like
> while( U1STAbits.UTXBF); // wait while Tx buffer full
> U1TXREG = 'a';
And I run step by step and find that U1TXREG never read in anything.
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