Displaying a variable current value?

Comments

• kuroneko Posts: 3,623

  2011-04-26 20:20 edited 2011-04-26 20:20

  CON
  
  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000
  
  OBJ
  ser : "FullDuplexSerialPlus"
  
  PUB main | Number, Value
  
  ser.Start(31, 30, 0, 9600)
  waitcnt(clkfreq*2+cnt)
  
  repeat
    ser.Str(String("Valor recibido por MATLAB:"))
    Number := ser.rx
    [COLOR="red"]Value := ser.GetDec[/COLOR]
    ser.Dec(Number)
    ser.tx(13)
    if Number=="1"
      dira[4]~~
      outa[4]~~
  

  The line in red is a blocking call, i.e. read a numeric string until CR is received then return its numeric value. So when used with PST you probably typed "1" followed by Enter which fires up the LED. If Matlab only sends the "1" then you're stuck in the GetDec call. For a quick test simply remove/comment this line and observe the different behaviour.
• lolobond Posts: 14

  2011-04-26 20:39 edited 2011-04-26 20:39

  Thank You for the quick respones. I tried it but it still does not work.
  This is my Matlab code
  

  s=serial('COM3','BaudRate',9600);
  fopen(s);
  ledon=[1];
  fwrite(s,ledon)
  fclose(s);
  

  
  Is there anyway to check what variable am I receiving from Matlab?
• kuroneko Posts: 3,623

  2011-04-26 20:46 edited 2011-04-26 20:46

  s=serial('COM3','BaudRate',9600);
  fopen(s);
  ledon=[1];
  fwrite(s,ledon)
  fclose(s);
  

  OK, that looks like a numeric one rather than the character "1" (numeric 49). To monitor incoming data you can use something like this:

  repeat
    ser.hex(ser.rx, 2)          ' or ser.dec(ser.rx) if you prefer
    ser.tx(" ")
  

  which displays each incoming character (or rather its numeric value) back to you separated by a space.
• lolobond Posts: 14

  2011-04-26 21:49 edited 2011-04-26 21:49

  1) So I can use the PST to monitor incoming data from Matlab by using the code you sent me?
  2) Yes, is a numeric 1, do I need to change any coding to make it work?
  3) For the last block of code you sent me, should I delete everything else in the repeat block and just copy paste that?
  
  Sorry for the questions, I am a beginner excited to understand and make this work
  
  Thank You
• kuroneko Posts: 3,623

  2011-04-26 22:55 edited 2011-04-26 22:55

  lolobond wrote: »

  1) So I can use the PST to monitor incoming data from Matlab by using the code you sent me?
  2) Yes, is a numeric 1, do I need to change any coding to make it work?
  3) For the last block of code you sent me, should I delete everything else in the repeat block and just copy paste that?

  
  Sorry for the delay, had a walk at the beach.
  
  1. yes
  2. if Number == 1 ' no quotes around the 1
  3. That would only be useful for continuous monitoring. Just remove the GetDec call from your original code for now:

  dira[4]~~
  repeat
    ser.Str(String("Valor recibido por MATLAB:"))
    Number := ser.rx
    [COLOR="red"]ser.Dec(Number)
    ser.tx(13)[/COLOR]
    [COLOR="blue"]if Number == 1[/COLOR]
      !outa[4]            ' toggle LED for each incoming 1
  

  The red bit does the monitoring/echo for you.
• lolobond Posts: 14

  2011-04-27 11:01 edited 2011-04-27 11:01

  I tried the code you posted but it is still not working. Also I am trying to use PST to monitor what the propeller is receiving from Matlab but I have to choose between using COM3 for the PST or COM3 for the Matlab program. Can't use COM3 for both at the same time hence can't monitor whatever I get from Matlab...
• kuroneko Posts: 3,623

  2011-04-27 16:25 edited 2011-04-27 16:25

  lolobond wrote: »

  I tried the code you posted but it is still not working. Also I am trying to use PST to monitor what the propeller is receiving from Matlab but I have to choose between using COM3 for the PST or COM3 for the Matlab program. Can't use COM3 for both at the same time hence can't monitor whatever I get from Matlab...

  OK, apologies. I was under the impression that you had the ability to split the serial connection. Then lets take a step back. Change your loop to something like this:

  dira[4]~~
  repeat
    Number := ser.rx
    !outa[4]            ' toggle LED for each incoming character
  

  ser.rx will block until there is a character available. Then send either more than one or a single character repeatedly from Matlab. This will at least verify that the data is arriving at this end (LED should flash). If this works then we can reintroduce the numeric filter again.
  
  I'm not familiar with Matlab but it would be worth checking how bidirectional file I/O works. There must be an equivalent fread() call which would allow you to see debug output in Matlab.
• StefanL38 Posts: 2,292

  2011-04-27 22:58 edited 2011-04-27 22:58

  Hi lolobond,
  
  please tell us what you want to do in the end.
  if we (the other forum-members) have an overview about your project much better solutions can be found.
  
  If you are just want to learn the basics about using the propeller and are using mathlab just because you are familiar with it
  I would recommend to switch to EZLog from hannoware instead of using mathlab.
  
  If you are forced to use mathlab then it would be interesting to know which board you are using.
  
  On a PPDB you have a second serial interface ready to use which could be used for debugging parallel to the communication with mathlab.
  on other boards you can use any propeller-IO-pins to establish another interface.
  
  So what do you want to do in the en?
  
  best regards
  
  Stefan
• lolobond Posts: 14

  2011-05-03 12:08 edited 2011-05-03 12:08

  Just wanted to thank you and let you know that I solved the problem. The problem was in the Matlab Code, I needed to pause the program for two seconds right after opening the port for serial communication. Now, it works perfectly.