Looking for suggestions pertaining to new object

Comments

• idbruce Posts: 6,197

  2011-02-03 12:37 edited 2011-02-03 12:37

  Marko
  
  My apologies, I fell asleep after eating something last night. As per our discussion last night, that error check was eliminated due to the handshaking revision. To avoid possible ENQ collisions, I altered the InterComm object and the demo to help prevent this from occuring. Please note the changes below to the InterComm object:
  

  'Used by the parent object to determine if
    'an enquiry(ENQ) has been received, to help
    'avoid ENQ collisions
    LONG EnquiryReceived 'TRUE or FALSE
  

  PUB IsHandshakeInitiated
    RETURN (EnquiryReceived <> 0)
  

  PRI ProvideInterComm
    
    REPEAT    
    
      IF InterCommMode == RX
        WaitForStatusEnquiry
      
        ReceiveDataWithCRC
      EnquiryReceived := FALSE
      IF InterCommMode == TX
  

  PRI WaitForStatusEnquiry
    REPEAT WHILE InterCommMode <> TX
    
      IF Serial.Rxtime(500) == ENQ
        EnquiryReceived := TRUE
        Serial.Tx(RECEIVER_IS_READY)
        QUIT
  

  
  And the following changes were made in the demo:
  

  PUB MasterTransmitSlaveReceive(LongValue1, LongValue2)
    Serial.Str(STRING("The Master Is Now Sending Two Long Values To The Slave!"))
    Serial.Tx(CR)
    REPEAT WHILE Master.IsHandshakeInitiated == TRUE
    MasterTransmitTwoLongsToSlave(LongValue1, LongValue2)
  

  PUB SlaveTransmitMasterReceive(LongValue1, LongValue2)
    Serial.Str(STRING("The Slave Is Now Sending Two Long Values To The Master!"))
    Serial.Tx(CR)
    REPEAT WHILE Slave.IsHandshakeInitiated == TRUE
    SlaveTransmitTwoLongsToMaster(LongValue1, LongValue2)
  

  
  The attached demo includes these changes.
  
  Bruce
• idbruce Posts: 6,197

  2011-02-03 14:23 edited 2011-02-03 14:23

  Marko
  
  Since my last post and update, I further updated the InterComm object as per MagIO2's recommendations as follows:
  

  Hi Bruce,
  
  some comments from my side:
  1. You could move parsing after checking the CRC. Then you don't do the work in case the transmission was faulty.
  2. Before putting it into the Obex, you should decrease the stacksize to the minimum. Some projects need to squeeze out any byte.
  3. I see a problem with the if condition in the trim function. You should add OR CHAR==0. Then the trim will return latest when it found the string-end. With the CRC check before parsing it shoud not happen often that you parse a "rubbish" message, but even with CRC it can happen, as with a bad connection also the CRC could be corrupted and by coincindents match with the corrupt message.

  
  Please see the new attachment below
  
  Bruce