get_string problem

[tkidder]

using 18f452 in a barcode application.
To find the current mastercode in the barcode scanner i send
the serial command.

printf("<M1>");
The scanner responds with a serial string terminated with a carriage return.

For some reason i am unable to recover the string being sent back.
Using rda interrupt.

#int_RDA
RDA_isr()
{
printf(lcd_putc,"in rda");
gets(Buffer);
printf(lcd_putc,"%s",Buffer);
}

The program seems to hang on the gets instruction.
There must be something in the buffer or the interrupt
wouldnt fire. I have tried Get_String and getc() with similar results.

any help would be greatly appreciated.

[rnielsen]

The problem is that the gets() function is hanging because your first printf() statement is taking way too much time and the data, from your scanner, is already gone before the printf() is finished. Never, ever put a printf() in an ISR. ISR's should be short and sweet. If you need to verify which step the ISR is at then I would suggest you use LED's and set outputs along the way. Have your gets() be the first thing. Actually, I would use a getc() and stuff each character into a char bucket and then look at that bucket in the main body.


Ronald