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Add GPS/PARSE to 8xSERVO-MOTOR CODE in Oshonsoft

Code:
        If RCSTA.OERR Or RCSTA.FERR Then    'neither of these should ever occur.
            RCSTA.CREN = 0                'this is kinda wishful thinking
            While PIR1.RCIF            'if any bytes in the buffer
                rec = RCREG                'throw them away
            Wend
            RCSTA.CREN = 1                'as any data received is corrupt

Just fyi - a framing error (FERR) won't prevent the uart from getting more chars. It's set when a STOP bit wasn't detected at the right time, so it's usually a baud rate error. Nothing really needs to be done hardware-wise.

Overrun error (OERR) will completely block you out, so that one definitely has to be handled (you've lost chars). Usually it's good enough to just toggle CREN, but you might as well toss what's in the fifo too...
Code:
RCSTA.CREN = 0 
rec = RCREG                'throw them away
rec = RCREG                'throw them away
RCSTA.CREN = 1
 
Code:
        If RCSTA.OERR Or RCSTA.FERR Then    'neither of these should ever occur.
            RCSTA.CREN = 0                'this is kinda wishful thinking
            While PIR1.RCIF            'if any bytes in the buffer
                rec = RCREG                'throw them away
            Wend
            RCSTA.CREN = 1                'as any data received is corrupt

Just fyi - a framing error (FERR) won't prevent the uart from getting more chars. It's set when a STOP bit wasn't detected at the right time, so it's usually a baud rate error. Nothing really needs to be done hardware-wise.

Overrun error (OERR) will completely block you out, so that one definitely has to be handled (you've lost chars). Usually it's good enough to just toggle CREN, but you might as well toss what's in the fifo too...
Code:
RCSTA.CREN = 0
rec = RCREG                'throw them away
rec = RCREG                'throw them away
RCSTA.CREN = 1
Hi T,
Thanks. (It's a little beyond me, but I'll try to keep up)

I notice 2x RCREG ! This cropped up earlier, and I seem to recall that the buffer sometimes has 2x CHARs to clear.

I'm not sure what's happening at the moment, as it's gone quiet, and all of the later CODEs have the same title [ 18F4431 32MHz XTL REMOTE_SLAVE 164 160223 2330 ] which I change for my records, but ths causes mix ups.

I'm working through earlier working CODEs to get my bearings.
C
 
That's what happens when you don't have else if.

Mike.
Hi M,
But where do you put an 'else if' when it's needed?

I'm working through an older program, where there's an IF ENDIF, and it blocks, so I added ELSE print FAIL, and it now show FAIL, So this must be what M means?
C
 
Last edited:
Hi M and ALL,
The SERVO 'shift register' works fine, also the 1Hz LED flash, and I'm sure I'll figure out where the ELSE goes in the GPS READ section.
The 'shift register' was a test between alternative CODEs, but I think there has been so much time and effort spent, that I will adopt it permanently.
Thanks for all of your efforts.
Cheers, C.
 
Hi,
I went back to earlier CODE before the 2x$ problem, and it now controls the SERVOs and outputs LON and LAT.
This will 'do' for now, until we connect the 2xPICs via SPI, so no RC1 output (for testing) needed,
Next, once SPI has been sorted out, the actual flying CODE will be started.
C
 
Last edited:
Hi,
I tested the MAIN program and SERVO program which were both OK.

Here I've added the SERVO into the MAIN Program. (There are bits that need deleting and tidying up) I don't expect a full trouble shoot, but if some on would scan through it in case there are obvious mistakes, as I try to get it all working properly.
At the moment, the GPS sentences are being read, parsed and SEROUTED, but the SERVOs move in a jerky way. I'm sure this can be sorted out, but I'll hve to watch it for a while, to see what can be done.

Also this PIC is where the control calculations will be done, and I need to know where do these go, and what time can be taken up before it breaks the program?

C
Code:
'18F4431 32MHz XTL PCB9 BASE_SLAVE NO-MATCH SERVO E 220224 1500
'array buf removed, losing 50 bytes of program memory from use
'parse routinr modified to cope with gps() which now integrates
'the gps parse routine into the main program rather than having it as a separate
'stand alone module
'????copy into the sspbuf array module removed as it is not needed anymore -?????
'I am in 2 minds about tidying up the serial print the diagnostic string data
'but have Not DONE anything with  it yet
'TRIS direction information

Define CONFIG1L = 0x00
Define CONFIG1H = 0x06  '8mHz x4 =32
Define CONFIG2L = 0x0c
Define CONFIG2H = 0x20
Define CONFIG3L = 0x04
Define CONFIG3H = 0x80
Define CONFIG4L = 0x80  'Set for HVP
Define CONFIG4H = 0x00
Define CONFIG5L = 0x0f
Define CONFIG5H = 0xc0
Define CONFIG6L = 0x0f
Define CONFIG6H = 0xe0
Define CONFIG7L = 0x0f
Define CONFIG7H = 0x40

'OSH config
Define CLOCK_FREQUENCY = 32
Define SINGLE_DECIMAL_PLACES = 2
Define STRING_MAX_LENGTH = 45  '20 too short@
Define SEROUT_DELAYUS = 1000

'**********************************************************************
'*                                                                    *
'*      Register configuration                                        *
'*                                                                    *
'**********************************************************************
'------------- TARGET SETUP  ------------------
Const PR2set = 125  'use this for the live board: gets 5ms per interrupt
'Const PR2set = 2  'use this for fast timing to speed up simulator
'Define SIMULATION_WAITMS_VALUE = 1  'Comment in for SIM out for PIC

ANSEL0 = %00000000
ANSEL1 = %00000000

Disable High  'Disable interrupts
Disable Low  'Disable interrupts

'**********************************************************************
'*                                                                    *
'*          IO Port configuration                                     *
'*                                                                    *
'**********************************************************************
'IN or OUT
Const TRISAinit = %11000000  '7=OSC, 6=OSC, 4=/ 3=/ 2=TEMP SEROUT
Const TRISBinit = %00000000
Const TRISCinit = %11110010  '7=1-RX, 6=1-slave4431_cs, 4-5=??, 3=74HC164 MR, 2=74HC164 CLK, 1=?, 0=74HC164 
Const TRISDinit = %00100000  '6=led, 7=led, 5=synch, 2=MOSI
Const TRISEinit = %00000000  '2=TEST INDICATOR, 0= S2M_BUF_FULL

LATC.0 = 0  'ensure data is low
LATC.2 = 0  'and clock
LATC.3 = 1  'Master reset HIGH for run.'<<<<<<<<<<<<<<

TRISA = TRISAinit
TRISB = TRISBinit
TRISC = TRISCinit
TRISD = TRISDinit
TRISE = TRISEinit

'SET BITS ON/OFF before TRIS!
Const LATAinit = %00000000  'ON/OFF
Const LATBinit = %00000000
Const LATCinit = %00000000
Const LATDinit = %00000000
Const LATEinit = %00000000  'POSS MCLR RE3

'*******************************************************
'*                                                     *
'*       GLOBAL VARIABLE DECLARATIONS                  *
'*                                                     *
'*******************************************************
'Comms

Const rxbufsize = 50  'keep this the same as the buffer size, check this.
Dim gnrmcpsn As Byte  'POSITION of character in UART RX buffer STRING.
Dim RXerr As Bit  'Errors in receiving $DATA

Dim RXIRQchar As Byte
Dim dumpchar As Byte  'For clearing Over run errors

Dim spipsn As Byte  'VARIABLE USED IN SSPBUF SEND/RECEIVE ROUTINE
Dim spichar As Byte

'SLAVE GPS
Dim strtim As String
Dim strlat As String
Dim strlong As String

'Dim qeideg As Word  ' Byte
'QEI section remove@
'QEICON.VELM = 1  '1 = Velocity mode disabled
'QEICON.QEIM2 = 1  '110 = QEI enabled in 4x Update mode; position counter is reset on period match (POSCNT = MAXCNT)
'QEICON.QEIM1 = 1
'QEICON.QEIM0 = 0
'QEICON.PDEC1 = 1  '11=1:64 Velocity Pulse Reduction Ratio bits
'QEICON.PDEC1 = 1
'PIR3.IC2QEIF = 0  'Has reached the MAXCNT value, INT QEI MODULE Interrupt flag bit
'PIR3.IC3DRIF = 0  'clr in s/w   REG file motion feedback filter

PIE1.RCIE = 0  '0= 'EUSART Receive Interrupt Enable bit

'CAP2BUFL = 0x00
'CAP2BUFH = 0x00
'CAP3BUFL = 0x9f  'CAP3BUFL = 0x67
'CAP3BUFH = 0x05  'CAP3BUFH = 0x01

''PIC18F4431

'FLAGS to indicate updated data
Symbol slave4431_cs = PORTC.6  'The port used as chip select
Dim gnrmc_buf_filling As Bit  'Message loading
Dim gnrmc_buf_full As Bit  'GPS-Buffer $ to W   1 = FULL 0 = Not FULL
'Dim gnrmc_buf_parsed As Bit  'parser found a GNRMC sentence and updated data
'gnrmc_buf_parsed = 0  'init new data flags (compiler may do this automatically)

'Dim s2m_buf_done As Bit  'S2M-buffer after PARSE
Symbol spi_pin_rdy = PORTE.0  'READY to send SPI DATA.
spi_pin_rdy = 0
Dim slave4431_cs_data As Bit  'The data state of the chip select line D added
Dim gnrmc_buf As String  '(45) As String'Byte  'received message comes to buf'Check size (Only for GNRMC)
Dim s2m(34) As Byte  '(34) As Byte  'Used to transfer data via SPI
'from the ssp buffer for receiving via the spi bus. The array has to be the same length as s2m buffer.
'onto the ssp buffer for transmitting via the spi bus. data includes the gps string,
'battery voltage and spare info.
Dim m2s(34) As Byte  'Used to transfer data to SLAVE via SPI

'********************* SERVO *******************************
Dim wordTemp As Word
Dim ServoCount As Byte
Dim i As Word
Dim ServoPos(8) As Word
Dim servoDir(8) As Byte
Dim frame As Word
'Dim gpsbuf(80) As Byte
Dim strCount As Byte
Dim rec As Byte
Dim isDone As Bit

Dim pos As Word'SERVO'<<<<<<<<<<<<<<<<<
Dim dir As Byte

Dim batvolt As Byte  'TEST Battery voltage from BASE-SLAVE
Dim sparedata As Byte  'TEST Spare data from BASE-SLAVE.

Symbol yled = PORTD.6
Symbol rled = PORTD.7

'*******************************************************
'*                                                     *
'*            End of variable declarations             *
'*                                                     *
'*******************************************************
'*******************************************************
'*                                                     *
'*            START UP CODE BEGINS HERE                *
'*                                                     *
'*******************************************************

'START UP LEDS
rled = 1
WaitMs 1000
rled = 0
WaitMs 1000
yled = 1
WaitMs 1000
yled = 0
WaitMs 1000

'setup USART for 9600 baud receive
RCSTA = %10010000  '7=SPEN: Serial Port Enable bit, 6=RX9: 9-Bit Receive Enable bit, 5=SREN: Single Receive Enable bit, 4=CREN: Continuous Receive Enable bit
TXSTA.BRGH = 1  'BRGH: High Baud Rate Select bit
BAUDCON.BRG16 = 1  '16-Bit Baud Rate Register Enable bi
SPBRG = 207
PIR1.RCIF = 0  'RCIF: EUSART Receive Interrupt Flag bit
PIE1.RCIE = 1  'EUSART Receive Interrupt Enable bit
PIE1.CCP1IE = 1  'CCP1IE: CCP1 Interrupt Enable bit
INTCON.PEIE = 1  'PEIE/GIEL: Peripheral Interrupt Enable bit
INTCON.GIE = 1  'GIE/GIEH: Global Interrupt Enable bit

Gosub irqinitbuf  'INIT RX'<<<<<<<<<<<<<<<¦
Serout PORTB.0, 9600, "RDY  ", CrLf  '"slave ready", CrLf  'USART?<<<<<<<<<<<<<<<<<<<<<<<<<<

'fire up the UART
Enable High  'enable the high interrupts

'INITIALIZE SPI
Call init_spi()  'initialise spi -here SSPEN=1 sets the pin directions for SPI

'ms20_reporttimer = 0  'force reports on entry to main loop

'++++++++++++++++++++++++++++++++++++++ SERVO ++++++++++++++++++++++++++++++++++++++++++++++++++


'If PIR1.RCIF Then
    'rec = RCREG  'get the received character
    'If RCSTA.OERR Or RCSTA.FERR Then  'neither of these should ever occur.
            'RCSTA.CREN = 0  'this is kinda wishful thinking
        'If PIR1.RCIF Then
            'rec = RCREG
        'Endif
        'RCSTA.CREN = 1  'as any data received is corrupt
        'strCount = 0  'however, reset everything
        'isDone = 0  'and hope for the best
    'Else  'no errors so use the data
        'If strCount = 0 And isDone = 0 Then  'are we already receiving
                ''waiting for $           'no so wait
            'If rec = "$" Then  'for $ to appear'<<<<<<<<<<<<<<<<<<<<<<<<
                'gpsbuf(strCount) = rec  'start receiving
                'strCount = strCount + 1
            'Endif
        'Else
            'If isDone = 0 And strCount < 79 Then  'have we collected a full string?
                'gpsbuf(strCount) = rec  'no so carry on storing
                'strCount = strCount + 1
                'If rec = "W" Then  'have we got the "endOfString" character'<<<<<<<<<<<<
                    'isDone = 1  'yes, so set done true
                    ''put break here
                'Endif
            'Else
                'If isDone = 0 Then  '?????????<<<<<<<<<<<<<<<<<<<<<<<
                '    ''still waiting to start or buffer overflow
                    'strCount = 0
                'Endif
            'Endif
        'Endif  '<<<<<<<<<<<<<<<
    'Endif
'Endif  'end RS232 if
'Resume
'++++++++++++++++++++++++++++++++++++++++ SERVO END ++++++++++++++++++++++++++++++++++++++++++++++


For i = 0 To 7
LATC.2 = 1  'send positive clock edge
ServoPos(i) = i * 250 + 2000  '1ms(2000) to 1.875(1 7/8ths - 3750)ms in 1/8th mS steps
LATC.2 = 0  'send negative edge
servoDir(i) = i And 1  '<<<<<<<added
Next i

'TRISC = %11111010  'CCP0 (RC2) & RC0 output'<<<<<<<<<<<<<<<<<<<<
ServoCount = 8  'cause it to reset
T1CON = %00100000  'prescaler = 4
T1CON.0 = 1  'start timer
CCP1CON = %1000  'will go high on interrupt - will start a 0.5mS pulse
frame = 1000  'start everything in 4000 cycles
strCount = 0
isDone = 0

''*******************************************************
''*                                                     *
''*            Main loop BEGINS                         *
''*                                                     *
''*******************************************************

'$GNRMC,111111.00,A,3723.02837,N,00150.39853,W,0.820,188.36,110706,,,A*74
'$GNRMC,000000.00,A,3723.02837,N,00150.00000,W,0.820,188.36,110706,,,A*74$GNRMC,111111.00,A,3723.02837,N,00150.11111,W,0.820,188.36,110706,,,A*74$GNRMC,222222.00,A,3723.02837,N,00150.22222,W,0.820,188.36,110706,,,A*74$GNRMX,333333.00,A,3723.02837,N,00150.33333,W,0.820,188.36,110706,,,A*74$GNRMC, 444444.00, A, 3723.02837, N, 00150.55555, W, 0.820, 188.36, 110706,,, A * 74$GNRMC, 555555.00, A, 3723.02837, N, 00150.39853, W, 0.820, 188.36, 110706,,, A * 74$GNRMC,666666.00,A,3723.02837,N,00150.66666,W,0.820,188.36,110706,,,A*74$GNRMX,777777.00,A,3723.02837,N,00150.77777,W,0.820,188.36,110706,,,A

main_loop:  '/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

Toggle rled

'Toggle PORTE.0

'Serout PORTB.0, 9600, "TEST", CrLf '<<<<<<<<<<<<<<<<<

If gnrmc_buf_full = 1 Then
    'Break  '<<<<<<<<<<<

    Gosub gnrmc_parse

    'Update the transmit to master buffer with current data
    batvolt = 12
    sparedata = 123
Endif

If spi_pin_rdy = 1 Then  'Tell MASTER SPI ready.<<<<<<<<<<<<<<<<<<<<<<<<<<<<
    Serout PORTB.0, 9600, "SLAVE GNRMC PARSED  ", s2m(0), s2m(1), s2m(2), s2m(3), s2m(4), s2m(5), s2m(6), s2m(7), s2m(8), s2m(9), s2m(10), s2m(11), s2m(12), s2m(13), s2m(14), s2m(15), s2m(16), s2m(17), s2m(18), s2m(19), s2m(20), s2m(21), s2m(22), s2m(23), s2m(24), s2m(25), s2m(26), s2m(27), s2m(28), s2m(29), s2m(30), s2m(31), #s2m(32), #s2m(33), CrLf
    WaitMs 1  'Lower till not work
    'Gosub irqinitbuf
Endif
    'If gnrmc_buf_parsed = 0 Then  'parse tried but string was unknown, corrupt or wrong length
        'Hserout "Parse fail ", CrLf
        'Gosub IRQinitBuf  '++++++¦
    'endif
    'Return
    yled = 1
    While slave4431_cs = 1  'If 1 then it waits till the CS makes it 0 then it LOOPs
        For spipsn = 0 To 33  'GPS=0to29-$toW INC, QEI=30,31 BATVOLT=32 SPARE DATA=33 'QEI?@
            SSPBUF = s2m(spipsn)  'Transfer S2M(spipsn) into SSPBUF
            While SSPSTAT.BF = 0
            Wend
            m2s(spipsn) = SSPBUF  'Transfer M2S(spipsn) BYTE from SSPBUF into M2S(spipsn)
        Next spipsn
            spi_pin_rdy = 0
    Wend
    spipsn = 0
    yled = 0
    RCSTA.CREN = 1
    PIE1.RCIE = 1
'Endif

    While ServoCount = 0  'wait for 20mS to pass (=1/50th of a second)
    Wend
    While ServoCount <> 0
    Wend
    For i = 0 To 7
        dir = servoDir(i)  'doesn't matter if ISR happens as servoPos isn't changed by ISR
        pos = ServoPos(i)
        If dir = 1 Then
            pos = pos + 40  'add 1/50th to the servo position
        Else
            pos = pos - 40  'subtract it
        Endif
        If pos < 2000 Then  'have we gone past the end?
            pos = 2000  'yes so make it the end stop
            dir = 1  'and turn it around
        Endif
        If pos > 4000 Then  'same for other end
            pos = 4000
            dir = 0
        Endif
        INTCON.GIE = 0
        ServoPos(i) = pos
        INTCON.GIE = 1
        servoDir(i) = dir  'servoDir not used by ISR
    Next i
'Wend



Goto main_loop

End

'*******************************************************
'*                                                     *
'*            Functions BEGIN                          *
'*                                                     *
'*******************************************************
'---------------------- RX/TMR2 INTERRUPT SERVICE  ----------------------
'Captures one sentence from '$' to 'W' in buf.
'Sentences must fit entirely in buf from $ to W
'Re-inits buf on any error and when any $ is received, even if in middle of sentence
'Stops UART and sets gps_buf_done when 'W' is received.

'Sentence in progress will be discarded, buffer reset and UART re-enabled when:
'Any UART error occurs
'A new '$' in the middle of a reception is found
'The buffer overflows before a 'W' is received. Non-fatal, it will just begin looking for the next
'sentence.  err will be set when this happens so that main knows about it.

'Returns gps_buf_done=1 and buffer loaded with $,data,W on successful receipt of a complete sentence.
'Requires:
'rxBufSize defined as the size of buf in bytes.  Declare the buffer like this:
'Const rxBufSize = 50
'Dim buf(50) As Byte  'Valid buf index range is 0 to rxBufSize-1.  After $, index points to last character stored

'Expects:
'Call IRQinitBuf with PIE1.RCIE = 0 to set up for next sentence
'$GNRMC,111111.00,A,3723.02837,N,00159.39853,W,0.820,188.36,110706,,,A*74'For SIM

On High Interrupt
Save System

'OVERRUN ERROR
If PIE1.RCIE = 1 Then  'EUSART Receive Interrupt Enable bit
    If RCSTA.OERR = 1 Then
        Gosub irqinitbuf  're-init buffer, discard bad sentence
        Goto RXIRQdone  'done, wait for next character
    Endif  'OERR

    'FRAMING ERROR
    If RCSTA.FERR = 1 Then
        dumpchar = RCREG  'Read char to clear RCIF and FERR
        Gosub irqinitbuf  'Re-init buffer, discard bad sentence
        Goto RXIRQdone  'wait for next
    Endif  'FERR

    'No UART errors, process character
    If PIR1.RCIF = 1 Then
        RXIRQchar = RCREG  'read the received char, clears RCIF

        'Look for $, start/restart filling buf when found
        If RXIRQchar = "$" Then  'Start (re)filling buf on any $
            Gosub irqinitbuf  'init buffer, index and flags@
            gnrmc_buf(gnrmcpsn) = RXIRQchar  'store $ $ ADDED instead of RXIRQchar, because no $ was being stored
            gnrmc_buf_filling = 1  'start storing the sentence
            Goto RXIRQdone  'done with this character
        Endif  'char was $



        'no UART errors and character was not $
        'If $ was found previously, process character looking for W and no buffer overflow.
        'If haven't found $ yet, just ignore character.

        If gnrmc_buf_filling = 1 Then  'if filling buffer, see if there is room in buf
        'Break  '<<<<<<<<<<<,
            If gnrmcpsn >= (rxbufsize - 1) Then  'last char was at end of buf - buffer overflow so..
                Gosub irqinitbuf  'restart buffer, discard sentence
                RXerr = 1  'let main know that the buffer overflowed and is restarting
                Goto RXIRQdone  'done, resume looking for next $
            Endif  'buffer overflow

            gnrmcpsn = gnrmcpsn + 1  'else, there's room in buf so bump index and store character, might be W
            gnrmc_buf(gnrmcpsn) = RXIRQchar

            If RXIRQchar = "W" Then  'if end of sentence..
                RCSTA.CREN = 0  'shut down UART
                PIE1.RCIE = 0  'Enable off
                gnrmc_buf_filling = 0
                gnrmc_buf_full = 1
                Goto RXIRQdone  'and bye!
            Endif  'RXIRQchar was W
        Endif  'If gnrmc_buf_filling = 1
    Endif  'RCIF=1
Endif  'RCIE=1

    'Exit point for each RXinterrupt. Process timers
    RXIRQdone:

'Resume
'On High Interrupt  'go via location 0x0008
'Save System

If PIR1.CCP1IF Then  'has CCP1 triggered?
    wordTemp.HB = CCPR1H  'get value of CCPR1 into wordTemp
    wordTemp.LB = CCPR1L
    If CCP1CON = 0x08 Then  'have we started the 1000 cycle pulse
        CCP1CON = 0x09  'yes so end the pulse after 0.5mS
        wordTemp = wordTemp + 1000  'adding 1000 will make pulse 0.5mS long
    Else
        LATC.0 = 0  'clear the data pin
        CCP1CON = 0x08  'No so output the timed gap
        If ServoCount < 8 Then
            'still doing the servos so add remainder of time
            wordTemp = wordTemp + ServoPos(ServoCount)
            wordTemp = wordTemp - 1000  'knock of the 1000 (0.5mS) already elapsed
            frame = frame - ServoPos(ServoCount)
            ServoCount = ServoCount + 1
        Else
            'done all the servos so just the frame gap to do
            wordTemp = wordTemp + frame
            frame = 39000  '40,000(20mS) minus time of positive pulse(0.5mS)
            ServoCount = 0  'start all over again
            LATC.0 = 1  'will become first pulse (is data pin of shift register)
        Endif
    Endif
        CCPR1H = wordTemp.HB  'put value back into CCPR1
        CCPR1L = wordTemp.LB
        PIR1.CCP1IF = 0  'clear interrupt flag
Endif
Resume

'--------------- PARSE COMPLETE SENTENCE IN BUFFER -------------------------
'parse: extracts the main values from GPS,REMOTE and QEIDEG sentences in RXbuf 'QEI@
'into named value messages using the parse utilities above.
'Flags:
'returns prsed_gnrmc =1 if it found A good sentence
'if prsed_gnrmc =0, has bad sentence
'posted to respective string(s).?¦

'Expects: gnrmcpsn = index in buffer of the termininating 'W' char (one less than number of chars):
'Const ixGNRMC_W = 15  '$gnrmc,025,4,75,W
Const ixGNRMC_W = 44

gnrmc_parse:
    'Break  '<<<<<<<<<<<<<<<<<<<<<<<<<
    gnrmc_buf_full = 0
    'Dim tempIX As Byte  'used as index for building/adding to strings
    'tempIX = 0  'string building begins at 0 for any

    If gnrmcpsn <> ixGNRMC_W Then Goto gnrmc_buf_parsed  '-->
    'Endif
    s2m(0) = "&"  '  [TOT 34 BYTES ] $TEST¦
    s2m(1) = gnrmc_buf(7)  'Time
    s2m(2) = gnrmc_buf(8)  'Time
    s2m(3) = gnrmc_buf(9)  'Time
    s2m(4) = gnrmc_buf(10)  'Time
    s2m(5) = gnrmc_buf(11)  'Time
    s2m(6) = gnrmc_buf(12)  'Time
    s2m(7) = gnrmc_buf(14)  'Time
    s2m(8) = gnrmc_buf(15)  'Time
    s2m(9) = gnrmc_buf(19)  'Lat
    s2m(10) = gnrmc_buf(20)  'Lat
    s2m(11) = gnrmc_buf(21)  'Lat
    s2m(12) = gnrmc_buf(22)  'Lat
    s2m(13) = gnrmc_buf(24)  'Lat
    s2m(14) = gnrmc_buf(25)  'Lat
    s2m(15) = gnrmc_buf(26)  'Lat
    s2m(16) = gnrmc_buf(27)  'Lat
    s2m(17) = gnrmc_buf(28)  'Lat
    s2m(18) = gnrmc_buf(30)  'N
    s2m(19) = gnrmc_buf(32)  'Lon
    s2m(20) = gnrmc_buf(33)  'Lon
    s2m(21) = gnrmc_buf(34)  'Lon
    s2m(22) = gnrmc_buf(35)  'Lon
    s2m(23) = gnrmc_buf(36)  'Lon
    s2m(24) = gnrmc_buf(38)  'Lon
    s2m(25) = gnrmc_buf(39)  'Lon
    s2m(26) = gnrmc_buf(40)  'Lon
    s2m(27) = gnrmc_buf(41)  'Lon
    s2m(28) = gnrmc_buf(42)  'Lon
    s2m(29) = gnrmc_buf(44)  'W
    's2m(30) = POSCNTL  'QEIDEGLB
    's2m(31) = POSCNTH  'QEIDEGHB
    s2m(32) = batvolt  'Bat volt
    s2m(33) = sparedata  'Spare DATA

    gnrmc_buf_parsed:  '<-- <--

    spi_pin_rdy = 1  'S2M Buffer ready to SPI to MASTER
    'Break  '<<<<<<<<<<<<  CS RC6 OFF
    'ms20_gnrmcguard = gnrmcguardset  '??????????
Return


'------------- UART SETUP UTILITIES  -----------------

'Stops UART, selects channel indicated by datasw (0-2)
'Inits RX buffer then restarts UART and enables RX interrupt
'Expects:
'GIE is enabled
'port directions and basic TX/RX

''--------------------  INIT SENTENCE BUFFER  ------------------
''Sets up index and flags for next sentence.  Overwrites
''old buffer data
''May be used by main (non-interrupt code) when PIR1.RCIE = 0

irqinitbuf:
    gnrmcpsn = 0  'init index
    RXerr = 0  'no error
    RCSTA.CREN = 1
    dumpchar = RCREG  '1    'clear UART RX registers
    dumpchar = RCREG  '2
    PIE1.RCIE = 1
Return

'*******************************************************
'*                                                     *
'*            START UP SPI ROUTINE                     *
'*                                                     *
'*******************************************************

Proc init_spi()  'PIC 18F4431
'4431
TRISC.6 = 1  '4431_CS=1
TRISD.3 = 1  'SCK from MASTER ******INPUT*****
TRISD.1 = 0  'MISO  ****** OUTPUT *******
TRISD.2 = 1  'MOSI  ****** INPUT *******

'MODE 0,0
SSPSTAT.SMP = 0  'Input data sampled at middle of data output time ** not about clock generation **
SSPSTAT.CKE = 0  '0 Output data changes on clock transition from active to idle ** AS ABOVE **
SSPSTAT.5 = 0  'I2C only
SSPSTAT.4 = 0  'I2C only
SSPSTAT.3 = 0  'I2C only
SSPSTAT.2 = 0  'I2C only
SSPSTAT.1 = 0  'I2C only

SSPCON = 0  'RESET THE CONTROL REGISTER
SSPCON.WCOL = 0  'Collision detect
SSPCON.SSPOV = 0  'Overflow
SSPCON.SSPEN = 1  'Configure SCK,SD0,SDI,/SS ** HAS TO BE 1. To reset or reconfigure SPI mode, clear the SSPEN bit,
'reinitialize the sspcon registers And Then set the SSPEN Bit from the datasheet !!!!!!!!!!!!!!!!
SSPCON.CKP = 1  '0 = Idle state for clock is a HIGH level
SSPCON.SSPM3 = 0  '0100 = SPI SLAVE mode, clock = FOSC/64
SSPCON.SSPM2 = 1
SSPCON.SSPM1 = 0  'SLAVE MODE
SSPCON.SSPM0 = 0
End Proc
 
You try to stop receiving RS232 by disabling the interrupt but another thing may interrupt and cause it to read the char.
To prevent this change the line,
If PIR1.RCIF = 1 Then
to
If PIR1.RCIF = 1 AND PIE1.RCIE=1 Then

It would be better to turn of the RS232.

Mike.
 
You try to stop receiving RS232 by disabling the interrupt but another thing may interrupt and cause it to read the char.
To prevent this change the line,
If PIR1.RCIF = 1 Then
to
If PIR1.RCIF = 1 AND PIE1.RCIE=1 Then

It would be better to turn of the RS232.

Mike.
Hi M,
Thanks for taking the time.

The 'If PIR1.RCIF = 1 AND PIE1.RCIE=1 Then' line didn't make any difference.

I think I have to roll back a bit to before adding the SERVO CODE, and make sure the MAIN program is running correctly.
If you agree and want me to post that program, I will.
C
 
The 'If PIR1.RCIF = 1 AND PIE1.RCIE=1 Then' line didn't make any difference.
It won't until PIE1.RCIE is set to zero which it is a little lower in the program.
However, you will still get overrun errors. Therefore it will be safer to disable the USART with RCSTA.SPEN=0.

Note, just checking the RCIF is dangerous if RCIE is set to zero.

Mike.
 
It won't until PIE1.RCIE is set to zero which it is a little lower in the program.
However, you will still get overrun errors. Therefore it will be safer to disable the USART with RCSTA.SPEN=0.

Note, just checking the RCIF is dangerous if RCIE is set to zero.

Mike.
Hi M,
Ok, thanks.
It will take me a while to understand this.

EDIT: Just spotted this which proves my point about taking me a while!
C.
 
Last edited:
Hi,
I can see that this UART probelem has been going for a long time, and still not correct.
Looking through it I thought I had addressed it, but it appears not.

Here is the CODE on the REMOTE SLAVE, also the 'irqinitbuf' that is GOSUB'ed

If someone would correct it please, I can test it.
C

Code:
On High Interrupt
Save System

'OVERRUN ERROR
If PIE1.RCIE = 1 Then  'EUSART Receive Interrupt Enable bit
    If RCSTA.OERR = 1 Then
        Gosub irqinitbuf  're-init buffer, discard bad sentence
        Goto RXIRQdone  'done, wait for next character
    Endif  'OERR

    'FRAMING ERROR
    If RCSTA.FERR = 1 Then
        dumpchar = RCREG  'Read char to clear RCIF and FERR
        Gosub irqinitbuf  'Re-init buffer, discard bad sentence
        Goto RXIRQdone  'wait for next
    Endif  'FERR

    'No UART errors, process character
    If PIR1.RCIF = 1 Then
        RXIRQchar = RCREG  'read the received char, clears RCIF

        'Look for $, start/restart filling buf when found
        If RXIRQchar = "$" Then  'Start (re)filling buf on any $
            Gosub irqinitbuf  'init buffer, index and flags@
            gnrmc_buf(gnrmcpsn) = RXIRQchar  'store $ $ ADDED instead of RXIRQchar, because no $ was being stored
            gnrmc_buf_filling = 1  'start storing the sentence
            Goto RXIRQdone  'done with this character
        Endif  'char was $



        'no UART errors and character was not $
        'If $ was found previously, process character looking for W and no buffer overflow.
        'If haven't found $ yet, just ignore character.

        If gnrmc_buf_filling = 1 Then  'if filling buffer, see if there is room in buf
        'Break  '<<<<<<<<<<<,
            If gnrmcpsn >= (rxbufsize - 1) Then  'last char was at end of buf - buffer overflow so..
                Gosub irqinitbuf  'restart buffer, discard sentence
                RXerr = 1  'let main know that the buffer overflowed and is restarting
                Goto RXIRQdone  'done, resume looking for next $
            Endif  'buffer overflow

            gnrmcpsn = gnrmcpsn + 1  'else, there's room in buf so bump index and store character, might be W
            gnrmc_buf(gnrmcpsn) = RXIRQchar

            If RXIRQchar = "W" Then  'if end of sentence..
                RCSTA.CREN = 0  'shut down UART
                PIE1.RCIE = 0  'Enable off
                gnrmc_buf_filling = 0
                gnrmc_buf_full = 1
                Goto RXIRQdone  'and bye!
            Endif  'RXIRQchar was W
        Endif  'If gnrmc_buf_filling = 1
    Endif  'RCIF=1
Endif  'RCIE=1

    'Exit point for each RXinterrupt. Process timers
    RXIRQdone:

'Resume
'On High Interrupt  'go via location 0x0008
'Save System

If PIR1.CCP1IF Then  'has CCP1 triggered?
    wordTemp.HB = CCPR1H  'get value of CCPR1 into wordTemp
    wordTemp.LB = CCPR1L
    If CCP1CON = 0x08 Then  'have we started the 1000 cycle pulse
        CCP1CON = 0x09  'yes so end the pulse after 0.5mS
        wordTemp = wordTemp + 1000  'adding 1000 will make pulse 0.5mS long
    Else
        LATC.0 = 0  'clear the data pin
        CCP1CON = 0x08  'No so output the timed gap
        If ServoCount < 8 Then
            'still doing the servos so add remainder of time
            wordTemp = wordTemp + ServoPos(ServoCount)
            wordTemp = wordTemp - 1000  'knock of the 1000 (0.5mS) already elapsed
            frame = frame - ServoPos(ServoCount)
            ServoCount = ServoCount + 1
        Else
            'done all the servos so just the frame gap to do
            wordTemp = wordTemp + frame
            frame = 39000  '40,000(20mS) minus time of positive pulse(0.5mS)
            ServoCount = 0  'start all over again
            LATC.0 = 1  'will become first pulse (is data pin of shift register)
        Endif
    Endif
        CCPR1H = wordTemp.HB  'put value back into CCPR1
        CCPR1L = wordTemp.LB
        PIR1.CCP1IF = 0  'clear interrupt flag
Endif
Resume

===============================================

Code:
'Stops UART, selects channel indicated by datasw (0-2)
'Inits RX buffer then restarts UART and enables RX interrupt
'Expects:
'GIE is enabled
'port directions and basic TX/RX

''--------------------  INIT SENTENCE BUFFER  ------------------
''Sets up index and flags for next sentence.  Overwrites
''old buffer data
''May be used by main (non-interrupt code) when PIR1.RCIE = 0

irqinitbuf:
    gnrmcpsn = 0  'init index
    RXerr = 0  'no error
    RCSTA.CREN = 1
    dumpchar = RCREG  '1    'clear UART RX registers
    dumpchar = RCREG  '2
    PIE1.RCIE = 1
Return
 
Hi,

Just had a thought!
Is this better for the irqinitbuf: GOSUB?
C.
============================================
irqinitbuf:
gnrmcpsn = 0 'init index
RXerr = 0 'no error
RCSTA.CREN = 0
PIE1.RCIE = 0
dumpchar = RCREG '1 'clear UART RX registers
dumpchar = RCREG '2
RCSTA.CREN = 1
PIE1.RCIE = 1
Return
 
The 'If PIR1.RCIF = 1 AND PIE1.RCIE=1 Then' line didn't make any difference.
It likely won't since the entire uart receive code is already surrounded by a check for RCIE=1:
Code:
'OVERRUN ERROR
If PIE1.RCIE = 1 Then  'EUSART Receive Interrupt Enable bit
    If RCSTA.OERR = 1 Then
        Gosub irqinitbuf  're-init buffer, discard bad sentence
        Goto RXIRQdone  'done, wait for next character
    Endif  'OERR

    'FRAMING ERROR
    If RCSTA.FERR = 1 Then
        dumpchar = RCREG  'Read char to clear RCIF and FERR
        Gosub irqinitbuf  'Re-init buffer, discard bad sentence
        Goto RXIRQdone  'wait for next
    Endif  'FERR

    'No UART errors, process character
    If PIR1.RCIF = 1 Then
Just checking for RCIF should be ok here since you've already checked for RCIE

Now, for the OERR handling... if OERR=1 then you have to clear it by either
clearing the CREN bit or by resetting the EUSART by clearing the SPEN bit.

The irqinitbuf code in post #295 does this... prior versions didn't.
 
It likely won't since the entire uart receive code is already surrounded by a check for RCIE=1:
Code:
'OVERRUN ERROR
If PIE1.RCIE = 1 Then  'EUSART Receive Interrupt Enable bit
    If RCSTA.OERR = 1 Then
        Gosub irqinitbuf  're-init buffer, discard bad sentence
        Goto RXIRQdone  'done, wait for next character
    Endif  'OERR

    'FRAMING ERROR
    If RCSTA.FERR = 1 Then
        dumpchar = RCREG  'Read char to clear RCIF and FERR
        Gosub irqinitbuf  'Re-init buffer, discard bad sentence
        Goto RXIRQdone  'wait for next
    Endif  'FERR

    'No UART errors, process character
    If PIR1.RCIF = 1 Then
Just checking for RCIF should be ok here since you've already checked for RCIE

Now, for the OERR handling... if OERR=1 then you have to clear it by either
clearing the CREN bit or by resetting the EUSART by clearing the SPEN bit.

The irqinitbuf code in post #295 does this... prior versions didn't.
Hi T and M,
Thanks, I'll use the #295 irqinitbuf
With the SEROUT commented out, the CODE is running much better.
I'll have to figure the best way of 'seeing' what's going on.
C
 
Hi M,
I'm trying to figure out how to send the SERVO Channels with individual numbers, instead of the #260 sweeping each channel.

I notice OSCCON = %01110000 '& h70.
The PIC has an 8mHz Crystal with 4xPLL, can I remove the OSCCON?
Is the timing the same?

EDIT: No reply! I'm a bit stuck with the calculations of the clock being 8mHz x4 (PLL). I'll ask on AAC.
C
 
Last edited:
Hi,
Here's my attempt at getting OSC changed from 8mHz to 32mHz.

It doesn't work?
C
Code:
'18F4431 32MHz PCB9 REMOTE_SLAVE SERVO 030324 0900

Define CONFIG1L = 0x00
Define CONFIG1H = 0x06  '8mHz XTL x4 =32mHz
Define CONFIG2L = 0x0c
Define CONFIG2H = 0x20
Define CONFIG3L = 0x04
Define CONFIG3H = 0x80
Define CONFIG4L = 0x80  'Set for HVP
Define CONFIG4H = 0x00
Define CONFIG5L = 0x0f
Define CONFIG5H = 0xc0
Define CONFIG6L = 0x0f
Define CONFIG6H = 0xe0
Define CONFIG7L = 0x0f
Define CONFIG7H = 0x40

Define CLOCK_FREQUENCY = 32
Define SINGLE_DECIMAL_PLACES = 2
Define STRING_MAX_LENGTH = 20

'Define SIMULATION_WAITMS_VALUE = 1  'Comment in for SIM out for PIC

Dim wordTemp As Word
Dim CHAN_Count As Byte
Dim i As Word
Dim Servo_CHAN(8) As Word
Dim servoDir(8) As Byte
Dim frame As Long 'Word
Dim rec As Byte
Dim pos As Word
Dim dir As Byte

Symbol rled = PORTD.7

'OSCCON = %01110000  '& h70 Using 8mHz XTL X4PLL
TRISA = %11000000  '7=OSC, 6=OSC,
TRISB = %00000000  '0=SEROUT
TRISC = %11110010  '6=1-slave4431_cs, 3=74HC164 MR, 2=74HC164 CLK, 0=74HC164 DATA'<<<<<<<<<<<<
TRISD = %00000000
LATC.0 = 0  'ensure data is low
LATC.2 = 0  'and clock
LATC.3 = 1  'Master reset HIGH for run.'<<<<<<<<<<<<<<

For i = 0 To 7
LATC.2 = 1  'send positive clock edge
'Servo_CHAN(i) = i * 250 + 2000  '250=1/8th-1ms(2000) to 1.875(1 7/8ths - 3750)ms in 1/8th mS steps
Servo_CHAN(i) = i * 1000 + 8000  '250=1/8th-1ms(2000) to 1.875(1 7/8ths - 3750)ms in 1/8th mS steps
LATC.2 = 0  'send negative edge
servoDir(i) = i And 1  '<<<<<<<added
Next i

'Start up led
rled = 1
WaitMs 1000
rled = 0
WaitMs 1000
rled = 1
WaitMs 1000
rled = 0
WaitMs 1000

'TRISC = %11111010  'CCP0 (RC2) & RC0 output'<<<<<<<<<<<<<<<<<<<<
CHAN_Count = 8  'cause it to reset
T1CON = %00100000  '=All values are divided by PRESCALE=4.
T1CON.0 = 1  '&00000001=EN start timer
CCP1CON = %1000  'will go high on interrupt - will start a 0.5mS pulse
'frame = 1000  'start everything in 4000 cycles
frame = 4000  'start everything in 16000 cycles
PIR1.RCIF = 0  'RCIF: EUSART Receive Interrupt Flag bit
PIE1.RCIE = 1  'EUSART Receive Interrupt Enable bit
PIE1.CCP1IE = 1  'CCP1IE: CCP1 Interrupt Enable bit
INTCON.PEIE = 1  'PEIE/GIEL: Peripheral Interrupt Enable bit
INTCON.GIE = 1  'GIE/GIEH: Global Interrupt Enable bit

While 1  '\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

    While CHAN_Count = 0  'wait for 20mS to pass (=1/50th of a second)
    Wend
    While CHAN_Count <> 0
    Wend
    For i = 0 To 7
        dir = servoDir(i)  'doesn't matter if ISR happens as servo_CHAN isn't changed by ISR
        pos = Servo_CHAN(i)
        If dir = 1 Then
            pos = pos + 160 '40  'add 1/50th to the servo position
        Else
            pos = pos - 160 '40  'subtract it
        Endif
        'If pos < 2000 Then  'have we gone past the end?
            'pos = 2000  'yes so make it the end stop
        If pos < 8000 Then  'have we gone past the end?
            pos = 8000  'yes so make it the end stop
            dir = 1  'and turn it around
        Endif
        'If pos > 4000 Then  'same for other end
            'pos = 4000
        If pos > 16000 Then  'same for other end
            pos = 16000
            dir = 0
        Endif
        INTCON.GIE = 0
        Servo_CHAN(i) = pos
        INTCON.GIE = 1
        servoDir(i) = dir  'servoDir not used by ISR
    Next i

Wend

End

On High Interrupt  'go via location 0x0008
Save System

If PIR1.CCP1IF Then  'has CCP1 triggered?
    wordTemp.HB = CCPR1H  'get value of CCPR1 into wordTemp
    wordTemp.LB = CCPR1L
    If CCP1CON = 0x08 Then  'have we started the 1000 cycle pulse
        CCP1CON = 0x09  'yes so end the pulse after 0.5mS
        'wordTemp = wordTemp + 4000  'adding 4000 will make pulse 0.5mS long
        wordTemp = wordTemp + 16000  'adding 16000 will make pulse 0.5mS long
    Else
        LATC.0 = 0  'clear the data pin
        CCP1CON = 0x08  'No so output the timed gap
        If CHAN_Count < 8 Then
            'still doing the servos so add remainder of time
            wordTemp = wordTemp + Servo_CHAN(CHAN_Count)
            'wordTemp = wordTemp - 4000  'knock of the 4000 (0.5mS) already elapsed
            wordTemp = wordTemp - 16000  'knock of the 16000 (0.5mS) already elapsed
            frame = frame - Servo_CHAN(CHAN_Count)
            CHAN_Count = CHAN_Count + 1
        Else
            'done all the servos so just the frame gap to do
            wordTemp = wordTemp + frame
            'frame = 39000  '40,000(20mS) minus time of positive pulse(0.5mS)
            frame = 165000  '160,000(20mS) minus time of positive pulse(0.5mS)
            CHAN_Count = 0  'start all over again
            LATC.0 = 1  'will become first pulse (is data pin of shift register)
        Endif
    Endif
        CCPR1H = wordTemp.HB  'put value back into CCPR1
        CCPR1L = wordTemp.LB
        PIR1.CCP1IF = 0  'clear interrupt flag
Endif

Resume
 

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