Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
20 years ago

communicate uart with VB

sorry, my english is poor.

I transmit a wavfile to Nios II within MSCOMM32.OCX

baud rate=115200 bps

data bit=8

parity bit=none

stop bit=1

RECEIVER in Nios II IDE 

  alt_16 buf;
  for(i=0;i<160;i++){
      fread(&buf, sizeof(alt_16), 1, uart);    //read data from file
      
      if(buf==0x4F4B) break;    //"OK"
      
      IOWR(USER_RAM_BASE, i, buf);    //write data to RAM and play sound
  }

My transmitter transmit data to receiver, but receiver get only incomplete data.

eg. I transmit 0x2353, 0x6411, 0x4235, receiver get only 0x2353, 0x6435, etc.

I guess that transmit speed too fast and transmit buffer too small.

But I can&#39;t how to solve it.

thx

Orz

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    if the uart buffer is overloaded then data will get lost.

    you should implement some handsahe between reciver and transmitter

    the buffer i&#39;m using is 64bytes so the transmiter will not send more then 64 bytes until the reciver didn&#39;t signal that it can read more bytes