SCI Reading(more than 1 char) problem

[aaronlee]

Hi,

I using AS1_OnRxChar() to read 1char. It work fine.

void AS1_OnRxChar(void)
{
   AS1_TComData ReceiveChar;
// Write your code here ...
   AS1_RecvChar(&ReceiveChar);
   Switch(ReceiveChar)
   {
   case 'C':
      Pin_RCK_Power = 0; // RCK POWER OFF
      break;
   case 'O':
      Pin_RCK_Power = 1; // RCK POWER ON
      break;
   default:
      break;
   }
 return;

}

Now, I want to read more than 1 char. But it still read 1st char only.

void AS1_OnRxCharExt(AS1_TComData Chr)
{
 uint8_tRxStatus;
 uint16_t  ReadSize=128, ReceiveLength, CompareCount, CheckInCount;

   static uint8_t   CheckIn[10]= {0x2f, 0xae, 0x22, 0x1e, 0x8d, 0x01, 0x0d, 0x6e, 0xcb, 0xf0};

/* Write your code here ... */
   ReceiveLength = AS1_GetCharsInRxBuf();                     ==> Always return 1, Why?
   RxStatus = AS1_RecvBlock(&Chr, ReadSize, &ReceiveLength);            ==> Retuen 10 (ERR_RXEMPTY)                                                                                                               Chr receive 1st char and ReceiveLength=1 Why?

   CompareCount=0;
   CheckInCount=0;
   while(CompareCount<10)
   {
      if(CheckIn[CompareCount++] == Chr++)
         CheckInCount++;
      else
         CompareCount = 10;
   }

   if(CompareCount == CheckInCount)
      Pin_RCK_Power = 1; // RCK POWER ON

}

Do you have any recommend?

Best Regards,

Aaron

[aaronlee]

Hi,

AS1_RecvBlock(&Chr, ReadSize, &ReceiveLength);

How to receive a string (not a char)? I can't understand that ReceiveLength always 1.

Best Regard,

Aaron

[Alice_Yang]

Hello Aaron,

You can use the method of " ASerialLdd1_ReceiveBlock()" to receive more than one char.

There is Typical usage :

Hope it helps

Have a great day,
TIC

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[rayhall]

I use interrupt for SCI transmitting and receiving a number of chars. I use a fixed packet format and read it into an array called RxData. Example....

/*  *********** SCI Packet *************
RxData[0]   = $ start char
RxData[1-2] = Packet size (Word)
Rxdata[3]   = Command ID  (byte)

and at the end
RxData[????] = Checksum (32bit)

When the whole packet is received the flag GotRx data is set. I  call the function CheckCommsActivity(); every 10 msec to see if there is any data.  

Below is how I do it...

//----------------------- SCI0 Rx/Tx Interrupt -----------------------------
interrupt void SCI0_ISR(void) {
 
   static uint16_t pkt = 0;
   static uint16_t x = 0;
   static uint8_t Schar = FALSE;    // Start char for comms
   uint8_t RxByte;
   static uint16_t i = 0;
   unsigned char scicr2,scisr1;      //prection against randomly flag clearing
   scisr1 = SCI0SR1;                // save status register actual status
   scicr2 = SCI0CR2;                // save control register actual status

    //if receiver interrupt is enabled and corresponding interrupt flag is set
   if((scicr2 & SCI0CR2_RIE_MASK) && ((scisr1 & (SCI0SR1_OR_MASK | SCI0SR1_RDRF_MASK)))) {
      if(scisr1 & SCI0SR1_OR_MASK)  {   // if overrun error do nothing
        (void)SCI0DRL;                  // clear interrupt flag
      } else {
        RxByte = SCI0DRL;             // read received character + clear interrupt flag
            
        switch (RxByte) {
       case 0x24 : RxData[x++] = RxByte; // $ Start char                 
               Schar = TRUE;
                   break;
         default : if (Schar == TRUE) {        
                  RxData[x++] = RxByte;
                       }
                       break;
        } // End Switch
        
        if (x == 3) {
       pkt = (RxData[x - 2] << 8);
       pkt = pkt + (RxByte & 0xFF);
        }                    
        
        if (x == pkt) {   // Last byte received      
       x = 0;
       pkt = 0;
           Schar = FALSE;
       gotRx = TRUE;                         
    }     
 }

}

}

//------------------ Check Comms Activity ---------------------------
void CheckCommsActivity(void)   {
  uint8_t cmd;
  if (gotRx == TRUE) {
        cmd = RxData[3];  // Read the forth byte which is the command
        switch (cmd) {
          case 0x01 : sendRealTimeData();
                  break;
      case 0x02 : receiveWholeMap();
                  break;
      case 0x03 : WriteStructureToEEprom((uint8_t *)&cal, sizeof(cal));   // Lock changes into flash
                  sendReply(0x03,TRUE); // Okay
                  break;
      case 0x04 : sendWholeMap();
              break;              
      case 0x05 : changeOfValueRequested();        
                break;
          case 0x06 : SetFpsMin();
                      break;
          case 0x07 : SetFpsMax();
                      break;
          case 0x08 : SetFuelTanksMin();
                      break;
          case 0x09 : SetFuelTanksMax();
                      break;
            }
      
         gotRx = FALSE;
     }
}

[aaronlee]

Hi, Ray,

Thanks for your reply. I'll try it later.

Our board connect to a instrument by RS232. The instrument sent data with rule as following:

1. No start char
2. No packet size
3. Only 4 command as following:

• uint8_t   Command_A[10]= {0x2f, 0xae, 0x22, 0x1e, 0x8d, 0x01, 0x0d, 0x6e, 0xcb, 0xf0};
• uint8_t   Command_B[8]= {0x2f, 0xae, 0x31, 0x31, 0x30, 0x30, 0x30, 0x30};
• uint8_t   Command_C[5]= {0x74, 0x75, 0x76, 0x77, 0x78};
• uint8_t   Command_D[7]= {0x30, 0x74, 0x32, 0x33, 0x2A, 0x01, 0xf3};

We need to know the instrument sent command is A, B, C or D. The challenge is that we don't know received char was 1st, 2nd, 3rd or other char of command.

Best Regard,

Aaron