1. Be sure you are in right bank for the handling the byte and any other
ports you use.

2. make sure you are using the correct syntax for numbers, you may be giving
the function the wrong char to test with.  A good way is to give it 'A'
instead of 65 decimal or 41 hex.

3. If you have transmit routines in chip too, start by echoing the char back
to the host to verify what you recieved.

4. Check logic and make sure you jump when you are supposed to.

Theese are just simple pointers that may help find your problem.

    KreAture

----- Original Message -----
From: "Olden A (SApS)" <aolden@GLAM.AC.UK>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Wednesday, January 22, 2003 9:00 PM
Subject: [PIC:] NEWBIE - Check To See What Letter Is Being Received from U
ART


> Hello Everybody,
>
> I've got a program, that should when it's finished receive a character in
> the range A-G from the UART, and depending on the character received
perform
> an AD Conversion of one of the pins, and transfer the result back to a PC
>
> now I've got the Serial Input Working, and the A/D Conversion, and (some
> form of transmission back)., but I think theres a problem in my logic to
> find out what character was being received.
>
> I thought that if I took the letter that received (the hex equilanant off
> anyway) and then checking the set/clear status of the Z bit, then I could
> find out which letter was received, ie. H'42' - H'42' would equal Z bit
set.
> But that doesn't seem to be happening, can anybody suggest a problem with
> that, either logically (ie I'm being stupid) or from the code below.
>
> Please Help.
> Andrew.
>
>
>
> loop
>      call               ser_in                  ; Call ser_in,
>      call               doconverstion           ; when finished in ser_in
> goto transmit w
>      goto       loop                    ; when finished transmitted, start
> ago.
>
> ser_in
>         btfsc   rcsta,oerr              ; does rcsta indicate an overflow
> error
>         goto    overerror               ; if so goto overerr
>         btfsc   rcsta,ferr              ; does rcsta indicate an frameing
> error
>         goto    frameerror              ; if so goto frameing error.
>
> uart_ready
>
>         btfss   pir1,rcif               ; Check If Data Received.
>         goto    ser_in          ; If Not goback and recheck.
>
> uart_gotit
>         bcf     intcon,gie              ; Clear This Pin
>         btfsc intcon,gie                ; Check If Cleared.
>         goto    uart_gotit              ; If Not Clear reset.
>
>         movf    rcreg,w                 ; recover UART data
>         bsf     intcon,gie              ; reanable interrupts
>         movwf   rx_data         ; save for later
>
>         return
>
> overerror
>                                         ; This Would Be Called if the UART
>                                         ; Subsystem went into a failure
>
>         bcf     rcsta,cren              ; recover from the error
>         movf    rcreg,w                 ; Flush The Input Buffer
>         movf    rcreg,w
>         movf    rcreg,w                 ; As Its Three Deep it will be
fine
> now
>         bsf     rcsta,cren              ; turn the cren back on.
>         bcf     PORTB,7                 ; Turn On the LEDS So That A
Problem
> Is Indicated
>         bcf     PORTB,5
>         bsf     PORTB,6
>
>         movf    'Z',txreg               ; Here We Transmit to z to the
HOST
> so that
>         movf    'Z',txreg               ; if these are received then the
> host knows
>                                         ; that it needs to resend the
> command.
>
>         goto    ser_in
>
> frameerror
>
>         bcf     rcsta,cren              ; recover from the error
>         movf    rcreg,w                 ; Flush The Input Buffer
>         movf    rcreg,w
>         movf    rcreg,w                 ; As Its Three Deep it will be
fine
> now
>         bsf     rcsta,cren              ; turn the cren back on.
>         bcf     PORTB,7                 ; Turn On the LEDS So That A
Problem
> Is Indicated
>         bsf     PORTB,5
>         bcf     PORTB,6
>
>         movf    'Z',txreg               ; Here We Transmit to z to the
HOST
> so that
>         movf    'Z',txreg               ; if these are received then the
> host knows
>                                         ; that it needs to resend the
> command.
>
>         goto    ser_in
>
> doconverstion
>
>         bcf     pir1,rcif               ; Here We Clear The Received
> Characters Flag,
>                                         ; Only because we have to do it
> sometime, and
>                                         ; to get this far we have to have
> received a char.
>
>         movf    rcreg,w                 ; move the received char into the
w
> register
>
>         subwf   'A',w                   ; subtract the char received from
> the contents
>                                         ; if we received a 'A' zero flag
of
> the status
>                                         ; register. If we didn;t then it
> should have skipped
>
>         btfsc   status,Z
>         call    do_A_Converstion
>
>         movf    rx_data,w
>         subwf   'B',w                   ; did we receive a b
>         btfsc   status,Z
>         call    do_B_Converstion
>         bcf     status,z
>         goto ser_in
>
> do_A_Converstion
>
>         movf    rcreg,txreg
>
>         return
>
> do_B_Converstion
>
>         movf    rcreg,txreg
>
>         return
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads