Array of Bytes to a "String" --- HELP!!!

zlantz · 2013-09-02 09:25

Ok, so this seems like a simple one, but it is giving me the most trouble.

I am recieving via serial a string of bytes "$1000|1500|1250|2000|<CR>" that is servo position data from my pc. I understand that being sent via serial, it is being received one char at a time, so I can create an array with the bytes myarray[0] = $, myarray[1] = 1, myarray[2] = 0 etc, but I cannot use this data to set my servo position. I need a full string in one var ie servopos1 = 1000, servopos2 = 1500, servopos3 = 1250, servopos4 = 2000.

how do I convert myarray[#] into a "string"?

bytemove just ends up with another array[#] of individual letters.

I have tried recoding the gps readNEMA code, as it is a stream of bytes, no luck.

I have a working parsing code, but it needs a full string (myString := "1000|1500|1250|2000|<CR>") to work.

I am stuck with a one byte array string that wont convert into a full sentence and is the only thing stopping my project.

Mike G · 2013-09-02 09:43

Welcome to the forum zlantz,

I'm thinking - you don't want to convert the incoming byte array to a string. It looks like a packet protocol, where the packet starts with a "$" and ends with a <CR>. In between the positions are 2 byte values - most likely- sent as [LSB][MSB].

For example, the value 1000 decimal is 0x03E8 hexadecimal. When received it looks like [0xE8][0x03].

But that's just a guess since there's no datasheet or reference accompanying the original post.

zlantz · 2013-09-02 10:29

I think I have solved my problem just now...

Con

_clkmode = xtal1 + pll16x
_xinfreq = 5_000_000

obj

ser : "fullduplexserial"

VAR

PUB Main | mStr, aStr, bStr
ser.start (31, 30, 0, 115200)

aStr := string("ABCD")

repeat
mStr := 0

AddString(mStr, aStr, string("ABcd"))

AddString(mStr, mStr, string("1234"))

AddString(mStr, mStr, string("$"))
AddString(mStr, mStr, string("1"))
AddString(mStr, mStr, string("0"))
AddString(mStr, mStr, string("0"))
AddString(mStr, mStr, string("0"))
AddString(mStr, mStr, string("|"))

ser.str(mStr)
ser.tx(13)

PRI AddString( dstStrPtr, srcStrPtr1, srcStrPtr2 ) | len
len := StrSize(srcStrPtr1)
ByteMove(dstStrPtr, srcStrPtr1, len)
ByteMove(dstStrPtr += len, srcStrPtr2, StrSize(srcStrPtr2)+1) '+1 for zero termination

on to parsing the data and testing with servos.

as for a little more info on how i have it set up:

PC running program that connects to a Raspberry Pi via tcp/ip, sends servo position data and receives sensor data

RPi running serial to ip 2 way redirector. Connected via WiFi. (Couldnt get RN-171 working completely (no data flow))

Prop receives servo data from RPi via serial uart and sends sensor data back

Prop decodes servo position data & updates position.

zlantz · 2013-09-02 10:42

or not, seems to work fine if your typing the string in by hand, but not if i replace string("$") with myArray[0]

Mike G · 2013-09-02 10:45

Wrap the SPIN code in code tags to preserve the indentation format.
[ code ]
... Code here
[ / code]

Are you sure the transmitted data is ASCII?

zlantz · 2013-09-02 10:45

Booyah!

Con

_clkmode = xtal1 + pll16x
_xinfreq = 5_000_000

obj

ser : "fullduplexserial"

VAR

byte myArray[6]

PUB Main | mStr, aStr, bStr, tmp
ser.start (31, 30, 0, 115200)

aStr := string(" ")

myArray[0] := string("$")
myArray[1] := string("1")
myArray[2] := string("0")
myArray[3] := string("0")
myArray[4] := string("1")
myArray[5] := string("|")

repeat
mStr := 0

AddString(mStr, aStr, myArray[0])
AddString(mStr, mStr, myArray[1])
AddString(mStr, mStr, myArray[2])
AddString(mStr, mStr, myArray[3])
AddString(mStr, mStr, myArray[4])
AddString(mStr, mStr, myArray[5])

ser.str(mStr)
ser.tx(13)

PRI AddString( dstStrPtr, srcStrPtr1, srcStrPtr2 ) | len
len := StrSize(srcStrPtr1)
ByteMove(dstStrPtr, srcStrPtr1, len)
ByteMove(dstStrPtr += len, srcStrPtr2, StrSize(srcStrPtr2)+1) '+1 for zero termination

Ariba · 2013-09-02 11:00

In your first post you say you will receive a string with the servo positions from the PC. But in your following posts you send the string to the PC. So what will you do really?

You can replace your code above with one line: ser.str(string("$1000|1500|1250|2000|",13))

Andy

zlantz · 2013-09-02 11:52

PC sends SERVO pos data to MCU,
MCU sends SENSOR data to PC.

At the same time.

the code above was to see if it worked by displaying the rebuilt string on the serial terminal.

in my code, ser.tx sends to propterm and rpi.tx sends to PC

btw im still having problems. that code works fine by itself, but when i join it in my big spin it gets all funky.

depending on how much code is running depends on weather my mcu sends/receives the correct data. one extra ser.tx(13) or anything basic can jam it all up.

but i have PLENTY of free space (nearly 6,000 longs)

i guess now i am having problems building the array from each recieved character. it needs to keep it self in order, $ starts <CR> ends data in the middle.

each time i try something new it garbles all my io data.

from the looks of it, as of right now, i can see the entire line, but it looks like the matrix on propTerm and it takes a while for one whole line to show up... i know its recieving very fast, i can un comment and recomment some code and it displays everything the pc is sending just fine.

Ariba · 2013-09-02 12:22

Okay, here is a possible solution.

This waits for Servo data and then sends the Sensor data back. Not both at the same time. You can use a second cog if you need it at the same time. I find it much simpler to receie and parse the characters in the same methode, than first receive a string and parse it later.

CON
 _clkmode = xtal1 + pll16x
 _xinfreq = 5_000_000

VAR
 long sensorData[4]
 long servoPos[4]

OBj
 ser : "FullDuplexSerial"

PUB Main
 ser.start (31, 30, 0, 115200)

 repeat
   rxServoData
   txSensorData


PRI txSensorData             'send 4 sensors decimal
 ser.tx("$")
 ser.dec(sensorData[0])
 ser.tx("|")
 ser.dec(sensorData[1])
 ser.tx("|")
 ser.dec(sensorData[2])
 ser.tx("|")
 ser.dec(sensorData[3])
 ser.tx("|")
 ser.tx(13)

   
PRI rxServoData : v | i,ch   'receive and parse servo data
 repeat until ser.rx=="$"
 repeat i from 0 to 3
   v := 0
   repeat
     ch := ser.rx
     case ch
       "0".."9":  v := v*10 + ch-"0"
       other:     quit
   servoPos[i] := v

this is not tested, but it compiles...

Andy

zlantz · 2013-09-02 12:44

this is in no way complete but this is what i have been using to test different areas, and right now is just returning trash

Con

  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000

  CR = 13

  RPitx  = 14
  RPirx  = 15

  
obj

  ser : "fullduplexserial"
  rpi : "fullduplexserial"
  

VAR

  long Servo1Pos, Servo2Pos, Servo3Pos, Servo4Pos, Servo5Pos, Servo6Pos, TxPower   ' RN-171 Storage
  long IR[12], BMP085_Pressure, HIH6130_Temp, HIH6130_Humidity                     ' Sensor Storage
  long Accel[3], Gyro[3], Magnet[3], RSSI                                          ' Sensor Storage

  long Altitude, Valid, Speed, Heading, Date, GPSaltitude, Time                    ' GPS Info
  long Latitude, N_S, Longitude, E_W, Satellites, Hdop, Vdop                       ' GPS Info                   

  long Data_stack[20], Build_stack[20]  
  long cog, cog2, cptr

  byte SVO_buff[23], sPos     

  
PUB Main | mStr, aStr
  ser.start (31, 30, 0, 115200)                ' To Prop Term
  rpi.start (RPirx, RPitx, 0, 57600)           ' To Raspberry Pi to PC
  
  cog  := cognew(DoRelay,    @Data_stack)  + 1 ' Data Relay
  cog2 := cognew(BuildArray, @Build_stack) + 1 ' Data Relay

  repeat

    SendDataRPi
     
    'Tmp := MakeStr
     
    ser.str(sPos)
    ser.tx(13)
     
    'if strsize(sPos) > 0
    '  ser.tx(sPos)
    '  ser.tx(13)
      
     
Pri BuildArray                  ' *** Runs in own cog

  repeat
     
    bytefill(svo_buff , 0, 23)
    
    repeat until sPos == "$"      ' wait for the $ to insure we are starting with

    cptr := 0

     
    repeat until sPos == CR       '  continue to collect data until the end of the NMEA sentence 

      svo_buff[cptr++] := sPos   '  else save the character                        
       
        
     
Pri DoRelay | TmpData, TmpData2  ' *** Runs in own cog    ( Any Delay will cause data to become garbled )

  repeat
          
    TmpData := rpi.rxCheck       ' Echo RPi Data  *** Had to use .rxCheck as .rx would just hang
    TmpData2 := ser.rxCheck      ' Echo Ser Data
                                                                                                     
    if TmpData > 0               ' Send RPi to PropTerm                                  
      sPos := TmpData            ' Export Data to Main Loop
      
    if TmpData2 > 0              ' Send PropTerm to RPi                                  
      rpi.tx(TmpData2)           ' *** Contains Debug Raw Write

      
Pri MakeStr | mStr, aStr  
                                     
  ' Currently Data = "$1500|1000|1250|2000|<CR>"  for servos 1, 2, 3, & 4   but sPos is only 1 char per rx     

  aStr := 13    ' *** Must Start with "something"

  mStr := 0     ' Reset myString
   
  ' 22 chars including CR
   
  AddString(mStr, aStr, SVO_buff[0])     ' Starts with <CR>
  AddString(mStr, mStr, SVO_buff[1])     ' $
  AddString(mStr, mStr, SVO_buff[2])
  AddString(mStr, mStr, SVO_buff[3])
  AddString(mStr, mStr, SVO_buff[4])
  AddString(mStr, mStr, SVO_buff[5])     
  AddString(mStr, mStr, SVO_buff[6])     ' |
  AddString(mStr, mStr, SVO_buff[7])
  AddString(mStr, mStr, SVO_buff[8])
  AddString(mStr, mStr, SVO_buff[9])
  AddString(mStr, mStr, SVO_buff[10])    
  AddString(mStr, mStr, SVO_buff[11])    ' |
  AddString(mStr, mStr, SVO_buff[12])
  AddString(mStr, mStr, SVO_buff[13])
  AddString(mStr, mStr, SVO_buff[14])
  AddString(mStr, mStr, SVO_buff[15])    
  AddString(mStr, mStr, SVO_buff[16])    ' |
  AddString(mStr, mStr, SVO_buff[17])
  AddString(mStr, mStr, SVO_buff[18])
  AddString(mStr, mStr, SVO_buff[19])
  AddString(mStr, mStr, SVO_buff[20])    
  AddString(mStr, mStr, SVO_buff[21])    ' |
  AddString(mStr, mStr, SVO_buff[22])    ' <CR>     *** Might get removed
   
      
  return mStr   

  
Pri AddString( dstStrPtr, srcStrPtr1, srcStrPtr2 ) | len
  len := StrSize(srcStrPtr1)
  ByteMove(dstStrPtr, srcStrPtr1, len)
  ByteMove(dstStrPtr += len, srcStrPtr2, StrSize(srcStrPtr2)+1)   '+1 for zero termination
            
 
Pri SendDataRPi                    ' Send Data to Base Station (Wifi Out)
     
    ' $GPRMC,081836,A,3751.6565,S,14507.3654,E,000.0,360.0,130998,011.3,E*62
    ' $GPGGA,170834,4124.8963,N,08151.6838,W,1,05,1.5,280.2,M,-34.0,M,,,*75
    ' $PGRMZ,453,f,2*18

    rpi.str(string("$GPS"))    ' GPS
    rpi.str(string(","))
    rpi.dec(0)
    'rpi.dec(GPS.Altitude)
    rpi.str(string(","))
    'rpi.dec(GPS.Valid)
    rpi.dec(0)
    rpi.str(string(","))
    'rpi.dec(GPS.Speed)
    rpi.dec(0)
    rpi.str(string(","))
    'rpi.dec(GPS.Heading)
    rpi.dec(0)
    rpi.str(string(","))
    'rpi.dec(GPS.Date)
    rpi.dec(0)
    rpi.str(string(","))
    'rpi.dec(GPS.GPSaltitude)
    rpi.dec(0)
    rpi.str(string(","))
    'rpi.dec(GPS.Time)
    rpi.dec(0)
    rpi.str(string(","))
    'rpi.dec(GPS.Latitude)
    rpi.dec(0)
    rpi.str(string(","))
    'rpi.dec(GPS.N_S)
    rpi.dec(0)
    rpi.str(string(","))
    'rpi.dec(GPS.Longitude)
    rpi.dec(0)
    rpi.str(string(","))
    'rpi.dec(GPS.E_W)
    rpi.dec(0)
    rpi.str(string(","))
    'rpi.dec(GPS.Satellites)
    rpi.dec(0)
    rpi.str(string(","))    
    'rpi.dec(GPS.Hdop)
    rpi.dec(0)
'    rpi.str(string(","))
'    rpi.dec(GPS.Vdop)
'    rpi.tx(13)

zlantz · 2013-09-02 12:52

Ok u did it! had to swap a few things around but this is showing correct data from my pc now:

CON
 _clkmode = xtal1 + pll16x
 _xinfreq = 5_000_000

 
VAR
 long sensorData[4]
 long servoPos[4]

 
OBj
 ser : "FullDuplexSerial"
 rpi : "fullduplexserial"  
 
PUB Main
 ser.start (31, 30, 0, 115200)
 rpi.start (15, 14, 0, 57600)           ' To Raspberry Pi to PC
 
 repeat
   rxServoData
   ShowServoData


PRI ShowServoData  | i           'send 4 sensors decimal

  ser.tx(0)

  repeat i from 0 to 3
    ser.str(string("Servo "))
    ser.dec(i)
    ser.str(string(" Pos: "))
    
    ser.dec(servoPos[i])

    ser.tx(13)
   
PRI rxServoData : v | i,ch   'receive and parse servo data
 repeat until rpi.rx=="$"
 repeat i from 0 to 3
   v := 0
   repeat
     ch := rpi.rx
     case ch
       "0".."9":  v := v*10 + ch-"0"
       other:     quit
   servoPos[i] := v

JonnyMac · 2013-09-02 12:59

I am recieving via serial a string of bytes "$1000|1500|1250|2000|<CR>" that is servo position data from my pc.

As a matter of curiosity, what PC program are you using to send this data? (I do a lot of work with animatronics)

zlantz · 2013-09-02 13:02

OMFG IT WORKS! HAHA! on to getting this thing hooked up to my helicopter!

Thank you soo much!

Zack

but exactly how does that handle the parsing?? if i were to change my chars around i would have no clue were to start. (notibly i probibly wont, but would still like to know)

zlantz · 2013-09-02 13:03

JonnyMac - i wrote my own vb6 progrm to handle it

JonnyMac · 2013-09-02 13:12

Got it.

You may want to add a bit of flexibility to your receive and parse routine -- right now it's locked into a specific array and number of servos. Simple changes let you point that code to another/different array, and work with any number of servos.

pub rx_servos(p_dest) | c, idx, value

'' Receive and parse servo positions
'' -- p_dest is address of servo positions array (words)

  repeat
    c := serial.rx
    if (c == "$")
      quit

  idx := 0

  repeat
    value := 0
    repeat
      c := serial.rx
      case c
        CR:
          return
      
        "0".."9":
          value := (value * 10) + (c - "0")

        other:
          word[p_dest][idx++] := value
          quit

Ariba · 2013-09-02 13:20

zlantz wrote: »

OMFG IT WORKS! HAHA! on to getting this thing hooked up to my helicopter!

Thank you soo much!

Zack

but exactly how does that handle the parsing?? if i were to change my chars around i would have no clue were to start. (notibly i probibly wont, but would still like to know)

Cool that it works (no clue what the F in OMFG could mean ;-)

How the parsing works:
First it waits until a "$" is received.
Then it receives every numeric character and "shifts" it in as the lowest digit of the decimal number.
If a not numerical character is received it must be the ending "|" and the decimal value is stored to the ServoData array.
This is repeated 4 times.
The CR is not tested (it is not necessary for the data, but it is useful if you show it on the Terminal).

Andy

zlantz · 2013-09-02 17:05

so if i wanted to add some extra data other than servo positions, how would i be able to include it?

JonnyMac · 2013-09-02 19:04

so if i wanted to add some extra data other than servo positions, how would i be able to include it?

Any way you want! -- you wrote the PC program that's sending values.

One thought is to use a different header character to send different groups of values. Of course, you'd have to modify the parser routine as the header character would now be used to determine the destination of values.

Array of Bytes to a "String" --- HELP!!!

Comments