Bluesmirf reading hex value with propeller

Ryoshima · 2011-11-16 18:24

This does involve a wireless topic but it's more of a propeller issue. When sending an ASCII command to a bluesmirf ('L'), the bluesmirf returns as an example:

RSSI=ff,fa

(the bluesmirf returns the whole line, RSSI= and all, above every time)

where both are hexadecimal values and the ff would be the current RSSI value and fa would be the lowest RSSI value that has been encountered.

Is there a way for me to just grab the bold ff portion?

Thanks

ratronic · 2011-11-16 19:21

Ryoshima if it always spits out the samething then perhaps you could do something like this

Pub main | i
  repeat until io.rx == "R"   
  repeat i from 0 to 2        
    io.rx                     
  if io.rx == "="             
    A := io.rx

Then A will equal the spot where ff is above.

Ryoshima · 2011-11-16 19:40

thanks for the reply ratronic, yes the same thing is being sent over and over, but the bold ff portion is always changing, the values can range from 00 to ff in hex. I only want to grab whatever current value is in that changing portion. Your code looks like its checking to see if the io.rx is some value, but the value that is being returned is:

RSSI=**,##

where ** is the changing hex value and the value I desire to capture.
I have used the propeller board for a while but haven't had to be to in depth with the coding, can you please elaborate on how your code works line by line?

Thank you!!

ratronic · 2011-11-16 19:51

The snippet I posted will return the value of the character sent in that position right after the "=". As far as to it's value it will be a byte (0-255, $0-$ff) and then A will equal whatever was sent in that position.

Edit: if you want to display the numeric value of A then use the .DEC(), .BIN(), .HEX() methods of your display device.

Ryoshima · 2011-11-16 20:08

Awesome, thank you so much!

Ryoshima · 2011-11-16 21:37

ratronic, sorry to post another question, but how do I assign a receive line? The code I have is:

OBJ
io      :       "FullDuplexSerial.spin"
Pub getRSSI : A | i
  repeat until io.rx == "R"   
  repeat i from 0 to 2        
    io.rx                     
  if io.rx == "="             
    A := io.rx

I assume you have to assign io.rx to a pin, but when I look into FULLSERIALDUPLEX, the rx function isn't setup to have an assigned pin.

ratronic · 2011-11-16 21:48

Ryoshima to start the fullduplexserial object

Con                                                          
                                                         
  _CLKMODE = XTAL1 + PLL16X                              
  _XINFREQ = 5_000_000   
Var
  long a
Obj 
   io : "fullduplexserial"
Pub main

  io.start(rxpin, txpin, mode, baudrate)

See the .start method of the fullduplexserial object for the meanings.

Edit: Also the clock needs to be set up.

frank freedman · 2011-11-16 22:06

Ryoshima wrote: »

This does involve a wireless topic but it's more of a propeller issue. When sending an ASCII command to a bluesmirf ('L'), the bluesmirf returns as an example:

RSSI=ff,fa

(the bluesmirf returns the whole line, RSSI= and all, above every time)

where both are hexadecimal values and the ff would be the current RSSI value and fa would be the lowest RSSI value that has been encountered.

Is there a way for me to just grab the bold ff portion?

Thanks

I am green at coding this on the prop (this is toddlers play in perl), but if it is a constant length string (is this something that one of the serial IO objects could handle?), I would input it into an array and read back the contents of the two bytes prior the null terminator to get the ascii representation of the hex value. Realize that if you want the actual binary value represented by the two bytes, you will have to add a routine to convert ascii to binary/hex for a true 8 bit single byte value. Bytes are as easy as any other length in spin, a bit more difficult in PASM as it works on 32 bit words.

ratronic · 2011-11-16 22:13

Frank there are multiple ways to get at it, I was just throwing out an idea to build upon. I've used the Propeller since it came out and I'm still feeling green about it!

frank freedman · 2011-11-16 22:26

ratronic wrote: »

Frank there are multiple ways to get at it, I was just throwing out an idea to build upon. I've used the Propeller since it came out and I'm still feeling green about it!

Yeah, I noted after I hit send that you referenced the fullduplex serial object. I have used that extensively in debugging my ADC capture object. It appears to be able to send a string, but most of the examples and the object look like the receive is limited to bytes as the examples usually build in a string handler for using it as an input.

Frank

@ratronic.
(Not to lazy to try it and code it, just wanted to throw the possibility out there. Finishing wiring up an SOIC op-amp into a .5 wide home-made dip header. My next A/D will be using the TI ADS7229. I expect it will tax the Prop chips speed if I can push it near its rated 1MSPS speed w/ 12 bit serial output. MCP3201 capture object @100ksps already posted.)

Ryoshima · 2011-11-16 23:20

EDIT: Had problem connecting bluesmirfs, fixed it. Solution is below.

Ryoshima · 2011-11-17 02:34

fixed the bluesmirf connection problem

OBJ
io      :       "FullDuplexSerial.spin"
pst     :       "Parallax Serial terminal" 
Pub getRSSI | i, A
pst.StartRxTx(0,1,0,9600)
pst.str(string("$$$"))
repeat 1000000
pst.NewLine
pst.Char("C")
pst.NewLine
repeat 1000000
pst.str(string("$$$"))
repeat 1000000
pst.NewLine
pst.Char("L")
pst.NewLine

Though this isn't working

CON
        _CLKMODE = XTAL1 + PLL16X
        _XINFREQ = 5_000_000
OBJ
io      :       "FullDuplexSerial.spin"
pst     :       "Parallax Serial terminal" 
Pub getRSSI | i, A
pst.StartRxTx(0,1,0,9600)
pst.str(string("$$$"))
repeat 1000000
pst.NewLine
pst.Char("C")
pst.NewLine
repeat 1000000
pst.str(string("$$$"))
repeat 1000000
pst.NewLine
pst.Char("L")
pst.NewLine
  repeat
    repeat until io.rx == "R"   
    repeat i from 0 to 2        
      io.rx                     
    if io.rx == "="             
      A := io.rx
    pst.clear
    pst.str(string("The Signal Strength is: "))
    pst.Hex(A,2)
    waitcnt(clkfreq/10 + cnt)

kuroneko · 2011-11-17 02:42

You have to start the io object as well, e.g.

io.start(31, 30, %0000, 115200)

Ryoshima · 2011-11-17 07:41

Tried this too, still nothing. I found this arduino code where this person was taking out returned data from the bluesmirf, does the propeller do anything similar to this?

 [B]while[/B][B]([/B]Serial[B].[/B][COLOR=#008080]available[/COLOR][B]()[/B] [B]<[/B] [COLOR=#009999]3[/COLOR][B]);[/B]
    str[B][[/B][COLOR=#009999]0[/COLOR][B]][/B] [B]=[/B] [B]([/B][COLOR=#445588][B]char[/B][/COLOR][B])[/B]Serial[B].[/B][COLOR=#008080]read[/COLOR][B]();[/B]
    str[B][[/B][COLOR=#009999]1[/COLOR][B]][/B] [B]=[/B] [B]([/B][COLOR=#445588][B]char[/B][/COLOR][B])[/B]Serial[B].[/B][COLOR=#008080]read[/COLOR][B]();[/B]
    str[B][[/B][COLOR=#009999]2[/COLOR][B]][/B] [B]=[/B] [B]([/B][COLOR=#445588][B]char[/B][/COLOR][B])[/B]Serial[B].[/B][COLOR=#008080]read[/COLOR][B]();[/B]  
    [B]if[/B][B]([/B]str[B][[/B][COLOR=#009999]0[/COLOR][B]][/B] [B]==[/B] [COLOR=#DD1144]'A'[/COLOR] [B]&&[/B] str[B][[/B][COLOR=#009999]1[/COLOR][B]][/B] [B]==[/B] [COLOR=#DD1144]'O'[/COLOR] [B]&&[/B] str[B][[/B][COLOR=#009999]2[/COLOR][B]][/B] [B]==[/B] [COLOR=#DD1144]'K'[/COLOR][B])

source: [/B]https://github.com/produceconsumerobot/MindSetArduino/blob/master/CleanProgramBlueSMiRF/CleanProgramBlueSMiRF.pde

P.S. I haven't been to sleep yet

ratronic · 2011-11-17 09:55

Ryoshima you probably want to use waitcnt for a delay instead of multiple repeats. In post #12 you didn't start the io object. I don't have a bluesmirf device to try but maybe this will get you a little farther.

CON
        _CLKMODE = XTAL1 + PLL16X
        _XINFREQ = 5_000_000
    
OBJ
io      :       "FullDuplexSerial.spin"
pst     :       "Parallax Serial terminal" 
Pub getRSSI | i, A
  pst.StartRxTx(31,30,0,9600)  'this starts the serial terminal for debug display
  waitcnt(clkfreq*3 + cnt)     'delay 3 seconds so you can open the parallax serial terminal
  io.start(0, 1, 0, 9600)      'this starts the serial port for your bluesmirf
  io.str(string("$$$"))        'this sends string
  
  repeat 1000000               'use waitcnt for delay
  io.tx(13)                    'transmit CHR/LF
  io.tx("C")                   'transmit "C"
  io.tx(13)                    'transmit CHR/LF
  repeat 1000000               'use waitcnt for delay
  io.str(string("$$$"))        'send string
  repeat 1000000               'use waitcnt for delay
  io.tx(13)                    'transmit CHR/LF 
  io.tx("L")                   'transmit "L"   
  io.tx(13)                    'transmit CHR/LF  
  repeat                                          'repeat continued
    repeat until io.rx == "R"                     'wait here until "R" received
    repeat i from 0 to 2                          'receive 3 more characters "SSI"
      io.rx                                       '
    if io.rx == "="                               'if the fifth character is "="
      A := io.rx                                  ' then assign A to sixth character
    pst.tx(1)                                     'home the display cursor
    pst.str(string("The Signal Strength is: "))   'print string to display
    pst.Hex(A,2)                                  'print value of A in 2 digit hex#
    waitcnt(clkfreq/10 + cnt)                     'delay 1/10 of a second

Edit get some sleep!

Ryoshima · 2011-11-21 13:07

Still nothing, Im trying to display this on the serial terminal so that the only thing printed out are the hexadecimal values

ratronic · 2011-11-21 14:22

I haven't looked at the datasheet for your device, the code I posted is only from things you originally put here. Maybe some one that's used bluesmirf can comment.

kuroneko · 2011-11-21 15:47

Ryoshima wrote: »

Still nothing, Im trying to display this on the serial terminal so that the only thing printed out are the hexadecimal values

Provided your serial links work, can you try this simple loop? It will dump the response to the L command in hexadecimal mode to the serial terminal.

repeat
  pst.hex(io.rx, 2)
  pst.char(32)

Ryoshima · 2011-11-30 18:03

Sorry I've been really busy with school. I got the program ratronic posted to work, but for full signal strength it gives me a '66' and not an 'ff'. When I make changes with the antenna direction, I get values from the USB to serial connection that vary greatly, but when I use the program I only get a '66' or '65', even though I use the same procedure.

kuroneko · 2011-11-30 18:15

Ryoshima wrote: »

I got the program ratronic posted to work, but for full signal strength it gives me a '66' and not an 'ff'.

66 is the hex representation of the lower case f, which suggests that the 'ff' you're expecting to see is sent as $66, $66 (it would have suprised me if if the data sent mixed ASCII and raw binary). That's why I asked you for a raw data dump to figure out the encoding.

Can you check what the byte after the first $66 is?

Ryoshima · 2011-11-30 18:18

ok sorry, how do I go about getting your raw data dump?

kuroneko · 2011-11-30 18:26

After the last io.tx(13) in ratronic's example (the one after sending L) just insert the repeat loop (instead of the one shown in his example), e.g.

io.tx("L")                   'transmit "L"   
  io.tx(13)                    'transmit CHR/LF  
  repeat                       'repeat continued
    pst.hex(io.rx, 2)
    pst.char(32)

Ryoshima · 2011-11-30 18:32

Here is what I pulled out

43 4D 44 0D 0A 3F 0D 0A 52 53 53 49 20 4F 4E 0D 0A 52 53 53 49 3D 66 66 2C66 66 0D 0A 52 53 53 49 3D 66 66 2C 66 66 0D 0A 52 53 53 49 3D 66 66 2C 66
66 0D 0A 52 53 53 49 3D 66 66 2C 66 66 0D 0A 52 53 53 49 3D 66 66 2C 66 66
0D 0A 52 53 53 49 3D 66 66 2C 66 66 0D 0A 52 53 53 49 3D 66 65 2C 66 65 0D
0A 52 53 53 49 3D 66 65 2C 66 65 0D 0A 52 53 53 49 3D 66 65 2C 66 65 0D 0A
52 53 53 49 3D 66 65 2C 66 65 0D 0A 52 53 53 49 3D 66 65 2C 66 65 0D 0A 52
53 53 49 3D 66 65 2C 66 65 0D 0A 52 53 53 49 3D 66 66 2C 66 65 0D 0A 52 53
53 49 3D 66 66 2C 66 65 0D 0A 52 53 53 49 3D 66 66 2C 66 65 0D 0A 52 53 53
49 3D 66 66 2C 66 65 0D 0A 52 53 53 49 3D 66 66 2C 66 65 0D 0A 52 53 53 49
3D 66 66 2C 66 65 0D 0A 52 53 53 49 3D 66 66 2C 66 65 0D 0A 52 53 53 49 3D
66 66 2C 66 65 0D 0A 52 53 53 49 3D 66 66 2C 66 65 0D

kuroneko · 2011-11-30 18:36

52 53 53 49 3D 66 66 2C 66 66 0D 0A
 R  S  S  I  =  f  f  ,  f  f CR LF

OK, so it's ASCII encoded. What this means for you is that you have to read two bytes and convert it to a single byte.

Ryoshima · 2011-11-30 18:46

so is there a case conversion I can run? $66 = f, $65 = e and so on?

EDIT: I suppose changing those to a usable integer range($66 = 100 ---> $?? = 0)?

kuroneko · 2011-11-30 18:56

Sort of, $30..$39 are normal digits, in this case all you do is value := char - $30. As for letters, assuming they only ever send lower case letters then the range here is $61..$66 and the corresponding value is value := char - $61 + 10. As you get two bytes the final result is value₁*16+value₂. There is also a huge number of conversion routines to be found in the forum. This topic comes up every now and then.

kuroneko · 2011-11-30 19:08

quick and dirty example:

PUB null | value

  value := convert("4")*16 + convert("A")

  dira[16..23]~~
  outa[16..23] := value

  waitpne(0, 0, 0)
  
PRI convert(char)

  case char
    "0".."9":           return char - "0"
    "a".."f", "A".."F": return (char | $20) - "a" + 10
    other:              abort

DAT

Ryoshima · 2011-11-30 20:35

what is the value of $20 for?

EDIT: its a space, but why still?

kuroneko · 2011-11-30 20:41

A lower case "a" is $61, capital "A" is $41. The $20 ("A" xor "a") makes sure that we only deal with lower case letters (otherwise the minus "a" wouldn't work).

Ryoshima · 2011-11-30 20:56

return (char | $20) - "a" + 10

if char = "b"

what would be returned?

Also, is there a good place I can go to learn about this stuff after we figure out this problem?

kuroneko · 2011-11-30 21:01

Ryoshima wrote: »

return (char | $20) - "a" + 10

if char = "b"

what would be returned?

Lower case "b" is $62. $62 | $20 is $62 (pipe symbol is binary OR). "a" would be $61 which leaves us with $62 - $61 + 10 = 11. Eleven decimal is "b" hex. That's what we wanted.

Using capital "C" ($43) as an example. $43 | $20 = $63, $63 - $61 + 10 = 12. Twelve decimal is "c" hex.

Bluesmirf reading hex value with propeller

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