Blockly and Xbee sending and receiving multiple variables

Comments

• dgately Posts: 1,621

  2020-01-27 04:21

  Just a guess but remove the "then a carriage return" checkmarks from all but the last of the Xbee Transmit blocks... Your input format in the receiver is expecting 6 decimal values without carriage returns between them.
  
  dgately
• graffix Posts: 389

  2020-01-27 05:11

  Thanks, removing the carriage returns I got this for results. I was looking into trying to packet the variables and send. Im not sure what the xbee is expecting to differentiate the next value. At first I thought the carriage returns were it. It may be an " ! " Then Id have to figure out how to block it out if it is that.

  

  

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• dgately Posts: 1,621

  2020-01-27 05:22 edited 2020-01-27 05:27

  Hmm... Put the checkmarks back in. You could try separate XBee receive blocks for each of the variables. Note: check the C code created with the "Code" button. It translates the XBee Receive into a C dscan command. I guess that the XBee transmit command needs either a carriage return or some whitespace between the sent decimal values.
  
  Try something like this for receiving each value:
  

  

  

  testMe.png

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• graffix Posts: 389

  2020-01-27 16:12

  That worked, I edited the arlo receiver code to something like that and Im receiving everything and the code works again. Thank You.... Now sadly I gotta try adding some more function to things and parts into the mix.
  
• graffix Posts: 389

  2020-01-28 14:56

  Are you or anyone else familiar with sending packets and confirming they were sent or the guard time of the xbees? Im reading the programming and customizing the propeller-chapter 5 and looking to apply some of that to my code using Blockly. Wouldnt sending the info in a single line help condense the code and make back and forth communications better? How would I go about that?
• dgately Posts: 1,621

  2020-01-29 02:03 edited 2020-01-29 02:06

  My experience with something similar...
  An XBee controller on a Propeller Project Board USB #32810 (has buttons and a joystick for control)
  An XBee on a Propeller Activity Board #32912, on a wheeled Parallax Stingray Robot frame
  
  As luck would have it, the program was written in Spin, and I was able to use JonnyMac's "HumanFriendlyControlProtocol" object. That object handles the processing of numeric and text data to/from any source (serial, XBee, etc...). Since you are using Blockly Prop, I'll just give you the jest of what might be done:

  Create a simple message protocol that you can parse easily. Keep it very simple, but use some key symbols that will allow you to debug that the message received is equal to the message sent:
  
    A symbol that identifies that start of a message (">"?)
    A delimiter to be used between data fields (comma?)
    A code to identify the message type (numeric, text, etc...)
    Since you will use a single line per packet, assume a carriage return as end-of-message
  
  
  Example string to send a numeric command code (works great for 10 numeric commands 0-9, but is expandable with numeric parsing of values greater than 9):
  
      ">,N,1"   '  Assume that ">" is the message-start
                    '  "," as delimiter
                    '  N says numeric value to follow
                    '  "," as delimiter
                    '  1 is a command value. Will need "scan string" to get a decimal value for this field
  
  You could expand this to include a number of numeric fields (commands) each separated by a comma.
  
  Text example:
  
      ">,A,a_text_command"   '   ">" is the message-start
                                            '  "," as delimiter
                                            '  A says alphabetic value to follow
                                            '  "," as delimiter
                                            '  a_text_command   ("move-foward", "turn-right", etc...)
  
  Note: You can simplify by removing the message-start, but I leave them in because I can easily see them within a digital logic probe during testing. 
  
  On the Receiving side, you would need to read in the string from the XBee (as you've done in your example), but will need to parse through the string, looking for '>', reading beyond any ","s, determining numeric (N) or text string (A), then gathering the data field(s) and processing the sent command(s).
  
  Start with simple numeric commands and use Blockly's Operators|Strings|split string OR scan string to 'parse' each field of the command string. Once you have the sent command value use the Blockly case block to process the command.
  

  
  Very simplified example... You'll want to check the msg-type before the case block...
  
  dgately
  

  

  

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