Hserin parsing string...again?

Hello all,

This has probably been answered in a million different threads...all of which I have read, which leads me to my question.
What I'de like to do is receive a string into the usart similar to this:

ABC123

What I would like to do is store the ABC in a word var to send through a
select case statement and...
store the 123 in a byte var to use later in code.

The commands coming into the usart will always be this format, for ex:

ABC123
XYZ255
PQR002

LETTER-LETTER-LETTER-NUMBER-NUMBER-NUMBER

NUMBER-NUMBER-NUMBER not to exceed 256.

Any help parsing these from the RCREG or a 6 byte ring buffer?

Thanks to all,
Chris

Follow up?

Am I on the right track?

Code:

Ser_Cmd_Word var word Ser_Cmd_Val var byte Start: ... If PIR1.5 = 1 Then Goto New_SerIn ... GOTO Start New_SerIn: PIE1 = %00000000 'Disable interrupts hserin [dec3 Ser_Cmd_Word, dec3 Ser_Cmd_Val] LCDout $fe, 1, "COMMAND RECEIVED" Lcdout $fe, $c0, "-----", Ser_Cmd_Word, Ser_Cmd_Val, "-----" pause 3000 'Pause for 3 seconds for user viewing PIE1 = %01110000 'Enable interrupts Return

Thanks much

3 letters won't fit in a word variable very easily.
Although it can be done, with limitations.

The second part ...
dec3 Ser_Cmd_Val
should work fine.

Is there a limit to the 3 letter sequences, or could it be anything?

Do you have PBP 2.60?
<br>

Thanks Darrel

If I understand your question correctly...yes, 3 characters- no more - no less. I did discover the 16 bit word size after my post...newbie move, i admit :). How about me changing the command to:

LETTER LETTER NUMBER NUMBER NUMBER

Easier coding that way? The ultimate goal is to run the LETTER LETTER through
a select case statement like:

Code:

Chk_Cmd: select case Ser_Cmd_word case TT 'Torch Target TTV_val = Ser_Cmd_Val Case XX 'Another Command 'SomeByteVar = Ser_Cmd_Val Case else LCDout $fe, 1, " COMMAND NOT IN " Lcdout $fe, $c0, " DEFINED SCOPE! " END SELECT RETURN

Am I on the right track?
Thanks again.

Well, I was referring to how many 3-letter combinations, and if you have PBP 2.60 it could be done differently.
However, let's go with what you have ...

First, I'd recommend starting the command sequence with a known character, like "$". This can keep the data "synced" by making it easy to find the beginning of each "packet". Then use the WAIT("$") modifier in HSERIN.

If you only have a few different commands, they can be reduced to 1 letter, which makes it work well with the Select Case statement. Then the packets might look like ...

$T123
$P255

Also, don't enable interrupts.
HSERIN does not use interrupts. And enabling them without handler routines being defined will cause the program to lock up.

If you want to keep the 2-letter commands, that can be done too, but it's a little trickier.
<br>

Will this fly...nearest you can tell?

Code:

'PIC 16F917 '------------------------------------------------------------------------------------------ 'Clock setup Define OSC 20 'Interrupt setups INTCON = %11000000 'Enable: Global interrupts, Peripheral interrupts PIE1 = %01110000 'Enable: ADC interrupt, Rx interrupt, Tx interrupt 'Pin setups ANSEL = %10000000 'Analog input on E.2/AN7, all others digital TRISA = %11000000 'PortA: 0-5 = output, 6-7 = input TRISB = %11111111 'PortB: 0-7 = input (defaults) TRISC = %11011111 'PortC: 0-5&7 = input, 6 = output TRISD = %11111111 'PortD: 0-7 = input (defaults) TRISE = %00000100 'PortE: 0&1 = output, 2 = input, 3-7 = N/A 'Vref setups VRCON = %10001111 'Enable Vref, set high range, set value (3.59 Vdc) 'Usart setups SPBRG = %00011001 'Set 9600 baud w/20MHz clock TXSTA = %00100110 'Enable transmit, set BRGH high RCSTA = %10010000 'Enable Usart, enable receiver 'ADC setups ADCON0 = %10011101 'Right justify (8 bit result in ADRESL), Select ch.7, enable ADC ADCON1 = %00100000 'Set ADC clock to 625kHz '------------------------------------------------------------------------------------------ 'LCD setup (16 x 2 lines) Define LCD_BITS 4 '4 data interface lines Define LCD_DREG PORTA 'LCD data port Define LCD_DBIT 0 'LCD data bits 0-4 Define LCD_RSREG PORTA 'LCD register select port Define LCD_RSBIT 4 'LCD register select bit Define LCD_EREG PORTA 'LCD enable port Define LCD_EBIT 5 'LCD enable bit '------------------------------------------------------------------------------------------ Ser_Cmd_Numb var byte Ser_Cmd_Val var byte THC_Enable_In var PORTC.0 TTV_Val var byte HYS_Val var byte Torch_V_Now var byte Torch_Up var PORTE.0 Torch_Dn var PORTE.1 TTV_Val = 120 HYS_Val = 0 pause 1000 'Pause for 1 second for LCD warmup LCDout $fe, 1, "---LCD WARMUP---" Lcdout $fe, $40, "----FINISHED----" pause 5000 'Pause for 5 seconds for user viewing Start: IF THC_Enable_In = 0 then PIE1.6 = 0 'Turn off ADC interrupt PIE1.5 = 1 'Turn on Rx interrupt LCDout $fe, 1, "READY TO RECEIVE" Lcdout $fe, $40, "COMMAND:C###V###" If PIR1.5 = 1 Then Goto New_SerIn PAUSE 500 GOTO START ELSE PIE1.6 = 1 'Turn on ADC interrupt PIE1.5 = 0 'Turn off Rx interrupt ADCON0.1 = 1 'Start ADC conversion if PIR1.6 = 1 THEN GOTO New_ADC LCDout $fe, 1, "TARGET VDC : ", dec TTV_Val Lcdout $fe, $40, "PLASMA VDC : ", dec Torch_V_Now select case Torch_V_Now case Torch_V_Now > TTV_Val + hys_val high torch_dn low torch_up case Torch_V_Now < TTV_Val - hys_val high torch_up low torch_dn case else low torch_up low torch_dn end select endif GOTO Start New_ADC: Torch_V_Now = ADRESL PIR1.6 = 0 Return New_SerIn: '******Command structure is: C###V### PIE1 = %00000000 'Disable interrupts hserin 100, start, [wait ("C"),dec3 Ser_Cmd_numb] hserin 100, start, [wait ("V"),dec3 Ser_Cmd_val] LCDout $fe, 1, "COMMAND RECEIVED" Lcdout $fe, $40, "-- C", dec Ser_Cmd_numb," V", dec Ser_Cmd_val, " --" pause 3000 'Pause for 3 seconds for user viewing GOTO Chk_Cmd PIE1 = %01110000 'Enable interrupts Return Chk_Cmd: select case Ser_Cmd_numb '001 to 256 case 1 'Torch Target Voltage TTV_val = Ser_Cmd_Val case 2 'Hysteresis Value HYS_Val = Ser_Cmd_Val Case else LCDout $fe, 1, " COMMAND NOT IN " Lcdout $fe, $40, " DEFINED SCOPE! " END SELECT RETURN

Cut and shuffle as you will :). Thanks guys.

Chris

Hello all,

Weird, I'm responding to my own thread :confused:. Well, I cut and shuffled my previous code for the better...I hope! Here it is, for the critique...

Code:

'PIC 16F76 '---------------------------------------------------------------------------- 'Clock setup Define OSC 20 'Interrupt setups INTCON = %11000000 'Enable: Global interrupts, Peripheral interrupts PIE1 = %01000000 'Enable: ADC interrupt 'ADC setups ADCON0 = %10000001 'ADC CLOCK = 625kHz, Select ch.0, enable ADC 'Pin setups TRISA = %00000001 'PortA: 1-5 = output, 0 = input, 6-7 = N/A TRISB = %11111111 'PortB: 0-7 = input (defaults) TRISC = %11111111 'PortC: 0-7 = input (defaults) 'Usart setups SPBRG = %00011001 'Set 9600 baud w/20MHz clock TXSTA = %00100110 'Enable transmit, set BRGH high RCSTA = %10010000 'Enable Usart, enable receiver '---------------------------------------------------------------------------- 'LCD setup (16 x 4 lines) DEFINE LCD_LINES 4 Define LCD_BITS 4 '4 data interface lines Define LCD_DREG PORTB 'LCD data port Define LCD_DBIT 4 'LCD data bits 0-4 Define LCD_RSREG PORTB 'LCD register select port Define LCD_RSBIT 3 'LCD register select bit Define LCD_EREG PORTB 'LCD enable port Define LCD_EBIT 0 'LCD enable bit '---------------------------------------------------------------------------- Setup_YN var byte Torch_Lock_Val var byte CNT VAR BYTE CNT2 VAR BYTE Hyst_Val var byte First_Run var bit Enable_In var PORTC.0 Torch_V_Now var byte Torch_Up var PORTE.0 Torch_Dn var PORTE.1 Torch_Lock_Val = 120 Hyst_Val = 0 first_run = 1 low enable_in pause 1000 LCDout $fe, 1 LCDout $fe, $03, "WELCOME TO THE" Lcdout $fe, $42, "DOUBLE DOWN IND." Lcdout $fe, $14, "TORCH HEIGHT CONTROL" Lcdout $fe, $54, "LCD WARMING UP" FOR CNT2 = 1 TO 5 FOR CNT = 0 TO 4 Lcdout $fe, $63 + CNT, "." PAUSE 400 Lcdout $fe, $63 + CNT, $20 NEXT CNT NEXT CNT2 Start: IF Enable_In = 0 then PIE1.6 = 0 'Turn off ADC interrupt '***** START MSG1 ***** LCDout $fe, 1 LCDout $fe, $03, "CONTROL IS IN" Lcdout $fe, $43, "STANDBY MODE." LCDout $fe, $15, "WOULD YOU LIKE TO" Lcdout $fe, $55, "RUN SETUP? (Y/N)" Lcdout $fe, $66 LCDOUT $fe, $0F '***** END MSG1 ***** HSERIN [Setup_YN] if setup_yn != "Y" then goto start Bad_Torch_Lock_Val: '***** START MSG2 ***** LCDout $fe, 1 LCDout $fe, $01, "ENTER A ", $22, "LOCK TO", $22 Lcdout $fe, $40, "TORCH VOLTAGE VALUE:" LCDout $fe, $17, $22, "X", $22, " TO EXIT OR" Lcdout $fe, $56, "(000 - 256) ___" Lcdout $fe, $63 LCDOUT $fe, $0F '***** END MSG2 ***** HSERIN [DEC Torch_Lock_Val] if (Torch_Lock_Val >= 0) and (Torch_Lock_Val <= 256) then goto Bad_Hyst_Val if Torch_Lock_Val = "X" then goto start '***** START ERR_MSG1 ***** LCDout $fe, 1 LCDout $fe, $02, "ONLY (000 - 256)" Lcdout $fe, $40, "ALLOWED!" LCDout $fe, $17, "PLEASE STANDBY" FOR CNT = 0 TO 19 Lcdout $fe, $54 + CNT, "." PAUSE 150 NEXT CNT '***** END ERR_MSG1 ***** GOTO Bad_Torch_Lock_Val Bad_Hyst_Val: '***** START MSG3 ***** LCDout $fe, 1 LCDout $fe, $01, "ENTER A HYSTERESIS" Lcdout $fe, $42, "+/- VOLTAGE VALUE:" LCDout $fe, $17, $22, "X", $22, " TO EXIT OR" Lcdout $fe, $58, "(0 - 5) _" Lcdout $fe, $63 LCDOUT $fe, $0F '***** END MSG3 ***** HSERIN [DEC hyst_Val] if (hyst_Val >= 0) and (hyst_Val < 6) then '***** START MSG4 ***** LCDout $fe, 1 LCDout $fe, $03, "SETUP COMPLETE" Lcdout $fe, $40, "TORCH LOCK VALUE=", Torch_Lock_Val LCDout $fe, $15, "HYSTERESIS VALUE=", hyst_Val FOR CNT = 0 TO 19 Lcdout $fe, $54 + CNT, "." PAUSE 300 NEXT CNT '***** END MSG4 ***** goto start endif if hyst_Val = "X" then goto start '***** START ERR_MSG2 ***** LCDout $fe, 1 LCDout $fe, $04, "ONLY (0 - 5)" Lcdout $fe, $46, "ALLOWED!" LCDout $fe, $17, "PLEASE STANDBY" FOR CNT = 0 TO 19 Lcdout $fe, $54 + CNT, "." PAUSE 150 NEXT CNT '***** END ERR_MSG2 ***** GOTO Bad_Hyst_Val first_run = 1 ELSE PIE1.6 = 1 'Turn on ADC interrupt ADCON0.2 = 1 'Start ADC conversion if PIR1.6 = 1 THEN GOTO New_ADC 'New ADC interrupt flag if first_run = 1 then LCDout $fe, 1 Lcdout $fe, $01, "PLASMA VOLTAGE=", Torch_V_Now Lcdout $fe, $40, "--------------------" Lcdout $fe, $14, "TORCH LOCK VALUE=", Torch_Lock_Val LCDout $fe, $55, "HYSTERESIS VALUE=", hyst_Val FIRST_RUN = 0 ELSE Lcdout $fe, $10, Torch_V_Now ENDIF select case Torch_V_Now case Torch_V_Now > Torch_Lock_Val + hysT_val high torch_dn low torch_up case Torch_V_Now < Torch_Lock_Val - hysT_val high torch_up low torch_dn case else low torch_up low torch_dn end select endif GOTO Start New_ADC: Torch_V_Now = ADRES 'Read ADC value into VAR PIR1.6 = 0 'Clear ADC interrupt flag Return

Does that seem to eliminate the string parsing gig altogether? I think I'm so stuck in the thinking of no LCD... First time I've messed with 'em. I think it just saved me a load of brain fry... I dunno?

Comments greatly appreciated!
Thanks all,
Chris

Can one of you fine folks look this revised code over to see if you think it'll do the trick. I heavily commented it for sake of keeping my head straight :confused: Anyhow, any thought are helpful thoughts at this point.
Thanks all,
Chris

Code:

'PIC 16F917 '---------------------------------------------------------------------------- 'Clock setup Define OSC 20 'Interrupt setups INTCON = %11000000 'Enable: Global interrupts, Peripheral interrupts PIE1 = %01100000 'Enable: ADC interrupt, Receive interrupt 'ADC setups ADCON0 = %10100001 'Rt justified, VRef + pin, Select ch.0, enable ADC ADCON1 = %00100000 'Fosc / 32 'Pin setups ANSEL = %00000001 'Port A.0 = analog input TRISA = %11101001 'PortA: 1,2,4 = output, 0,3,5,6,7 = input TRISB = %11000000 'PortB: 0-5 = LCD output, 6,7 = ICSP input TRISC = %11111111 'PortC: 0-7 = input (defaults) TRISD = %11111111 'PortD: 0-7 = input (defaults) TRISE = %11111111 'PortE: 0-2 = input (defaults), 3-7 = N/A 'Usart setups SPBRG = %00011001 'Set 9600 baud w/20MHz clock TXSTA = %00100110 'Enable transmit, set BRGH high RCSTA = %10010000 'Enable Usart, enable receiver '---------------------------------------------------------------------------- 'LCD setup (16 x 4 lines) DEFINE LCD_LINES 4 Define LCD_BITS 4 '4 data interface lines Define LCD_DREG PORTD 'LCD data port Define LCD_DBIT 4 'LCD data bits, pic starting pin 0 or 4 Define LCD_RSREG PORTD 'LCD register select port Define LCD_RSBIT 2 'LCD register select bit Define LCD_EREG PORTD 'LCD enable port Define LCD_EBIT 3 'LCD enable bit '---------------------------------------------------------------------------- 'Variable setups RxFlag VAR PIR1.5 RxInt var PIE1.5 ADCFlag var PIR1.6 ADCInt var PIE1.6 ADCGo var ADCON0.2 SerInStr var byte(25) X VAR BYTE ' Holds "$" start position Y VAR BYTE ' Holds "=" mid position Z VAR BYTE ' Holds "*" end position Index VAR BYTE ' Index pointer B0 VAR WORD B1 VAR WORD TorchLockVal var word CNT VAR BYTE CNT2 VAR BYTE TorchHystVal var byte FirstRun var bit TorchVNow var byte ControlIsTracking var PORTA.1 TorchUp var PORTA.2 TorchDn var PORTA.4 EnableIn var PORTA.5 InMotion var PORTE.1 'Initial variable values TorchLockVal = 120 TorchHystVal = 0 firstrun = 1 pause 1000 LCDout $fe, 1 LCDout $fe, $03, "WELCOME TO THE" Lcdout $fe, $42, "DOUBLE D ENT." Lcdout $fe, $14, "TORCH HEIGHT CONTROL" Lcdout $fe, $54, "LCD WARMING UP" FOR CNT2 = 1 TO 5 FOR CNT = 0 TO 4 Lcdout $fe, $63 + CNT, "." PAUSE 400 Lcdout $fe, $63 + CNT, $20 NEXT CNT NEXT CNT2 Start: 'Enter here if no Toolpath is running AND THC is not enabled IF (EnableIn = 0) and (InMotion = 0) then RxInt = 1 'Enable receive interrupt ADCInt = 0 'Disable ADC interrupt '***** START MSG1 ***** LCDout $fe, 1 LCDout $fe, $03, "CONTROL IS IN" Lcdout $fe, $43, "STANDBY MODE." LCDout $fe, $15, "READY TO RECEIVE" Lcdout $fe, $55, "A COMMAND" Lcdout $fe, $66 LCDOUT $fe, $0F '***** END MSG1 ***** firstrun = 1 'Enter here if Toolpath is running OR THC is enabled OR both ELSE RxInt = 0 'Disable receive interrupt ADCInt = 1 'Enable ADC interrupt ADCGo = 1 'Start ADC conversion if ADCFlag = 1 THEN GOTO NewADC 'New ADC interrupt flag if firstrun = 1 then 'Write the entire message LCDout $fe, 1 Lcdout $fe, $01, "PLASMA VOLTAGE=", TorchVNow Lcdout $fe, $40, "--------------------" Lcdout $fe, $14, "TORCH LOCK VALUE=", TorchLockVal LCDout $fe, $55, "HYSTERESIS VALUE=", TorchhystVal FIRSTRUN = 0 ELSE 'Write just the changed values Lcdout $fe, $10, TorchVNow ENDIF select case TorchVNow case TorchVNow > TorchLockVal + TorchhysTval 'Torch is too high, tell CNC to lower it high torchdn low torchup case TorchVNow < TorchLockVal - TorchhysTval 'Torch is too low, tell CNC to raise it high torchup low torchdn case else 'Torch is locked on, we're good low torchup low torchdn end select endif GOTO Start 'ADC interrupt routine------------------------------------------------------- NewADC: TorchVNow = ADRESL 'Read ADC value into VAR ADCFlag = 0 'Clear ADC interrupt flag Return '---------------------------------------------------------------------------- 'Serial interrupt routine---------------------------------------------------- SerialInt: 'Command structure ex: ' $CommandWord=###* RxInt = 0 'Disable receive interrupt SerInStr = 0 'Clear the buffer hserin[str SerInStr\25\42] 'Fill the buffer. Move on when "*" is found 'Thanks to Bruce: www.rentron.com for the parsing routine Get_Start: 'X will hold the start "$" position FOR X = 0 TO 24 'Iterate through the entire buffer IF SerInStr[X] = "$" THEN Get_Mid 'We found it, move on to next find NEXT X GOTO Start 'Buffer is empty or improper Command string Get_Mid: 'Y will hold the end "=" position FOR Y = X+1 TO 24 'Iterate through the buffer from last found to end IF SerInStr[Y] = "=" THEN Get_End 'We found it, move on to next find NEXT Y GOTO Start 'Buffer is empty or improper Command string Get_End: 'Z will hold the end "*" position FOR Z = Y+1 TO 24 'Iterate through the buffer from last found to end IF SerInStr[Z] = "*" THEN ParseCommand 'We found it, now let's parse it NEXT Z GOTO Start 'Buffer is empty or improper Command string

Continued below... over 10000 characters... sorry:(

Code:

ParseCommand: CmdLen var byte 'Declare byte var to hold "command word" string length cmdlen = y-x-1 'Calc string length by: "=" position - "$" position -1 CmdWord var byte(cmdlen) 'Declare byte array based on string length For Index = 0 to cmdlen-1 CmdWord[index] = SerInStr[index+x+1] 'Fill byte array with "command word" next index ValLen var byte 'Declare byte var to hold "command value" string length ValLen = z-y-1 'Calc string length by: "*" position - "=" position -1 CmdVal var byte(ValLen) 'Declare byte array based on string length For Index = 0 to ValLen-1 CmdVal[index] = (SerInStr[index+y+1]-"0") 'Fill byte array with "command value" next index if CmdWord = "SetTorchLockVal" then 'Compare variable "command word" with static string select case ValLen 'Do math to get byte value based on "command value" length case 1 TorchLockVal = CmdVal case 2 TorchLockVal = (CmdVal[0] * 10) + CmdVal[1] case 3 TorchLockVal = (CmdVal[0] * 100) + (CmdVal[1] * 10) + CmdVal[2] case else goto err_TorchLockVal end select if TorchLockVal > 255 then 'If we're NOT 8 bit, bad news err_TorchLockVal: '***** START ERR_MSG1 ***** LCDout $fe, 1 LCDout $fe, $02, "ONLY (000 - 255)" Lcdout $fe, $40, "ALLOWED!" LCDout $fe, $17, "PLEASE STANDBY" FOR CNT = 0 TO 19 Lcdout $fe, $54 + CNT, "." PAUSE 150 NEXT CNT '***** END ERR_MSG1 ***** SerInStr = 0 'Flush the buffer TorchLockVal = 0 'Flush the "Lock Value" RxInt = 1 'Enable receive interrupt GOTO Start 'Start over ELSE 'We're 8 bit, good '***** START MSG3 ***** LCDout $fe, 1 LCDout $fe, $01, "RECEIVED COMMAND:" Lcdout $fe, $42, CmdWord, "=",TorchLockVal LCDout $fe, $17, "TORCH LOCK VALUE" Lcdout $fe, $58, "SET TO: ", TorchLockVal '***** END MSG3 ***** SerInStr = 0 'Flush the buffer PAUSE 5000 '5 second view of LCD confirmation GOTO Start 'Start over endif endif if CmdWord = "SetTorchHystVal" then TorchHystVal = CmdVal if TorchHystVal > 6 then '***** START ERR_MSG2 ***** LCDout $fe, 1 LCDout $fe, $04, "ONLY (0 - 5)" Lcdout $fe, $46, "ALLOWED!" LCDout $fe, $17, "PLEASE STANDBY" FOR CNT = 0 TO 19 Lcdout $fe, $54 + CNT, "." PAUSE 150 NEXT CNT '***** END ERR_MSG2 ***** SerInStr = 0 TorchHystVal = 0 RxInt = 1 GOTO Start ELSE '***** START MSG3 ***** LCDout $fe, 1 LCDout $fe, $01, "RECEIVED COMMAND:" Lcdout $fe, $42, CmdWord, "=",TorchHystVal LCDout $fe, $17, "TORCH HYST. VALUE" Lcdout $fe, $58, "SET TO: ", TorchHystVal '***** END MSG3 ***** SerInStr = 0 PAUSE 5000 GOTO Start endif endif Return

Sorry guys for not compiling the above code before posting! Shame on me. I did fix all the errors with variables, with the exception of these:

Code:

... CmdWord var byte(cmdlen) '^^^^^Bad data type^^^^^ ... CmdVal var byte(ValLen) '^^^^^Bad data type^^^^^ ... if CmdWord = "SetTorchLockVal" then '^^^^^Bad expression^^^^^ ... if CmdWord = "SetTorchHystVal" then '^^^^^Bad expression^^^^^

Any thoughts as to what I'm doing wrong? Probably a newbie mistake, I hope.
Thanks again all,
Chris

Code:

... CmdWord var byte(cmdlen) '^^^^^Bad data type^^^^^ cmdlen is a variable. Array sizes can't be changed at run-time. It must be a constant. CmdVal var byte(ValLen) '^^^^^Bad data type^^^^^ ditto if CmdWord = "SetTorchLockVal" then '^^^^^Bad expression^^^^^ Do not pass GO, Do not collect $200. Do not attempt to compare strings. PBP doesn't have them. if CmdWord = "SetTorchHystVal" then '^^^^^Bad expression^^^^^ ditto

Thanks DT,

I kinda thought that was the deal... So I think I'm going to go with the "KISS" method and do something like my original thought:

Command String...

C###V###

Code:

CmdWord VAR word CmdVal VAR word HSERIN(wait ("C"), DEC3 CmdWord) HSERIN(wait ("V"), DEC3 CmdVal)

I think that will save me a load of code...I'll just have to write a command destruction manual so I know what command does what. Small price to pay, I think.

On a programming note: Say I want to make sure the CmdWord and CmdVal vars are within a byte sized var. I declare them as words, so I can compare later in code.
Would this be a simple way to do this...

If CmdWord < 255 Then
'We're good, do something with it
Else
'We are greater than 8 bit, bad command, start over
EndIf

Should I declare them as bytes right up front, and look for >255? What happens to the byte if say "500" is sent. Does it overflow to (500 - 255)... does the byte become "0" or "245". Hopefully that is not a way dumb question, just trying to not have to flash my chip a hundred times to change 1 line of code each time:o.

Thanks for your input DT,
Chris

Yeah, I think they should be words.

If they were bytes, anything received over 255 would truncate and become a smaller number that you could not detect as an error.

And if you're worried about errors, the addition of a checksum to your packet might help too.
<br>

Thanks DT,

Good idea on the checksum. I'll run with it from here, and see what happens. Thanks a ton for your help!

'Til next time,
Chris

Re: Hserin parsing string...again?

Hi All,
Can anyone offer an opinion on if this will work? I don't seem to be having much luck.

I'm trying to capture streaming data and there are a few sequences that I can key on to determine if I have a valid combination. So far the simplest is to look for the word "INVALID".
Here is one attempt:

Code:

' * * * * * * Interrupt handler ******* serialin: ' Buffer the character received buffer[7] = buffer[5] ' get the newest character into the buffer buffer[6] = buffer[5] ' and shift them into a sliding form buffer[5] = buffer[4] buffer[4] = buffer[3] buffer[3] = buffer[2] buffer[2] = buffer[1] buffer[1] = buffer[0] HSerin [buffer[0]] ' Read USART and store character in first position IF buffer[0]="I" and buffer[1]="N" and buffer[2]="V" and buffer[3]="A" then goto Freeze endif IF RCIF Then serialin ' Check for another character while we're here @ INT_RETURN ; Return to program

I'm under the belief that by " "ing an alpha character that it will recognize it as the ASCII character and do the compare. Can anyone explain what I'm missing?

A related question is " how do I catch a STX ($02) and a ETX ($03) with a number (4) and a non control character (X)in the middle? The data stream is STX, 4, X, $FF and I'm struggling how to compare mixed forms. Can I just use the ASCII numbers and compare them?

Sorry for such a simple question, but it's kicking my butt.

Thanks
Bo

Re: Hserin parsing string...again?

If this is a cut and paste, you have a mistake in the first line (buffer[7] = buffer[5] should be buffer[7] = buffer[6])

Re: Hserin parsing string...again?

I have a question.... Why not just move a pointer instead of copying all of the data each time a new character is received?
As far as comparing the data bytes, just compare the Hex or Decimal ascii equivelents? After all thats all your "buffer[0]="I" statement is doing, comparing the ASCII equivelent of the received byte.

Re: Hserin parsing string...again?

Hi Guys,
Thanks for the replies.
The (buffer[7] = buffer[5] error was because it was 4 in the morning and I had worked on it way too long. The characters after the 5th weren't used in the compare, they were only for display so that I could get some idea on if it were successful. Thanks for seeing that.

Dave, I have looked at quite a few examples of compares and they are not yet clicking with me. The data is coming in @ 9600, so its not too fast, but I still manage to miss it.
I've looked at this, this, and this. They all have good examples and I should be able to build something, but as of yet, no banana.

I think my best answer is to just try again and dissect these and try to code them for my use. I will have to understand this better.

Thanks
Bo

Re: Hserin parsing string...again?

Remember that it's all just numbers, if you want to check if a byte contains 'I' either of these will work

Code:

IF myByte = 73 THEN.... If myByte = "I" THEN.... IF myByte = $49 THEN.... IF myByte = %00110001 THEN...

They all do the same thing - they compare the content of myByte with the decimal value 73, which is the ASCII code for the letter 'I'.

Instead of using AND you might try something like:

Code:

IF Buffer[0] = "I" THEN IF Buffer[1] = "N" THEN IF Buffer[2] = "V" THEN IF Buffer[3] = "A" THEN GOTO Freeze ENDIF ENDIF ENDIF ENDIF

There's nothing wrong with the AND approach but I think using multiple IF statements will produce smaller code.

/Henrik.

Re: Hserin parsing string...again?

Thanks Henrik,

I just needed a sanity check. Too many hours and poor results.

I'll have a look at it when I get back to the shop. Maybe something obvious after some sleep and a fresh look.

Bo

Re: Hserin parsing string...again?

Dave, (and, of course, anyone else that care to respond)
I'm a bit confused about checking the data with a pointer. Do you mind explaining more?

I understand setting up a ring buffer similar to DT's serial LCD program. What I'm not sure is if I need to keep it cleaned out or something similar. If I just keep stepping the pointer around the loop, what happens when you fill the buffer? Does it just overwrite the previous data and keep circling the ring? After looking at that program for a long time, I finally believe that is what happens.

Still trying to work towards for that "Neo" moment when the Matrix just starts to come into focus....

Bo

Re: Hserin parsing string...again?

Dave, (and, of course, anyone else that care to respond)
I'm a bit confused about checking the data with a pointer. Do you mind explaining more?

I understand setting up a ring buffer similar to DT's serial LCD program. What I'm not sure is if I need to keep it cleaned out or something similar. If I just keep stepping the pointer around the loop, what happens when you fill the buffer? Does it just overwrite the previous data and keep circling the ring? After looking at that program for a long time, I finally believe that is what happens.

Still trying to work towards for that "Neo" moment when the Matrix just starts to come into focus....

Bo