16f887 and hserin/out

[Dennis]

Hi All

Just wondering if anyone has encountered weird behaviour with HSERIN/OUT using a 16F887 at all ?

I was using the 16F887 (hserout) as a receiver for data sent from a 18F4520 (hserin) as a receiver.

When I switch the roles so that the 16F887 is the transmitter and the 184520 is the receiver ... I either get mismatched data or no data at all !

Is it possible I have trhe wrong config settings for the registers on either side at all ?
for the 16F887 I have this

 'Set comparators off
CM1CON0 = %00000000
CM2CON0 = %00000000

OSCCON = %01110001          'Int CLK 8MHz
ANSEL = %00000000           'All digital
OPTION_REG.7 = 0            'Weak pull-ups enabled

DEFINE OSC 8                '8MHz
'TRIS statements
        TRISA  = %00000000 
        TRISB = %11111111  'for 4x4 keypad all input
        TRISC = %10100000 'PORTC.7 and C.5 are input
        TRISD = %00000000
        TRISE.0 = 0
        TRISE.1 = 0
        TRISE.2 = 0

and for the 18F4520 I have this

 OSCCON = $70            'Int CLK 8MHz
        OSCTUNE.6 = 1           'PLL 4x
        ADCON1= %00001111       '$0F = disable A/D converter
        cmcon   =   7 
        INTCON2.7 = 0     'switch pull-ups ON
'
        DEFINE OSC 32            '4x 8MHz
        TRISA  = %00000000 
        TRISB = %11111111  'for 4x4 keypad all input
        TRISC = %10010000 'PORTC.7 and C.4 are input
        TRISD = %00000000 'all output
        TRISE.0 = 0
        TRISE.1 = 0
        TRISE.2 = 0

Any suggestion would be appreciated.

Kind regards
Dennis

[Archangel]

Hi All

Just wondering if anyone has encountered weird behaviour with HSERIN/OUT using a 16F887 at all ?

I was using the 16F887 (hserout) as a receiver for data sent from a 18F4520 (hserin) as a receiver.

When I switch the roles so that the 16F887 is the transmitter and the 184520 is the receiver ... I either get mismatched data or no data at all !

Any suggestion would be appreciated.

Kind regards
Dennis

Hi Dennis,
The pic 16f887 and the pic18F4520 are different breeds of Cats, which is to say they require different configs and register settings. It may be you are experiencing ports that are not in full digital mode on the chips, esp. the 18F part which would explain the complete non op situation. as far as I know the setup numbers in the hserin vs hserout are the same within a given PIC and May in fact be the same across the line. Remember too that hserin/out sends data TRUE and never INVERTED and as such idles in a high state, which is to say it very much would like a pullup resistor on the line, that said, you May have inadvertanly set code to enable pullups on one of your chips, so make sure you have a pullup.
EDIT: you edited your post while I was typing, and I was using both fingers too

[Dennis]

Thanks Joe :-)

So a quick fix would be to disable pull-ups on the receiver PIC 16F887 ?
Fo rthe 18F4520 I have an LCD on PORTA and a 4x4 keypad on PORTB

FOR the 16F887 I have the following setting for HSERIN/OUT

 DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
    DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0
    DEFINE HSER_SPBRG 51  ' 2400 Baud @ 8MHz, 0.17%
    DEFINE HSER_CLROERR 1 ' Clear overflow automatically

and for the 184520

DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0
DEFINE HSER_SPBRG 207 ' 2400 Baud @ 32MHz, 0.17%
DEFINE HSER_CLROERR 1 ' Clear overflow automatically

Kind regards
Dennis

[Archangel]

Hi Dennis,
The PIC18F4520 has more registers to play . . .
SSPCON1.5 = 0
Will disable the synchronous Serial port and make it STD I/O. I am still looking for other issues . . .
Looks like on POR is should come up as zero but who knows?
Try RCSTA = %10010000
I am a little fuzzy on bit 5 though, read section 18 in the data sheet and it also says:

The pins of the Enhanced USART are multiplexed
with PORTC. In order to configure RC6/TX/CK and
RC7/RX/DT as a USART:
• bit SPEN (RCSTA<7>) must be set (= 1)
• bit TRISC<7> must be set (= 1)
• bit TRISC<6> must be set (= 1)
The operation of the Enhanced USART module is
controlled through three registers:
• Transmit Status and Control (TXSTA)
• Receive Status and Control (RCSTA)
• Baud Rate Control (BAUDCON)
These are detailed on the following pages in
Register 18-1, Register 18-2 and Register 18-3,
respectively.
Note: The EUSART control will automatically
reconfigure the pin from input to output as
needed.

[Dennis]

Hi Joe :-)
How are you ?

Just wondering whether my problem lies at 18F4520 or 16F887 !
You see when the 18F4520 was a set as the receiver and the 16F887 as a transmitter,
I would do an HSERIN to catch the data from the transmitter PIC and then an HSEROUT directly after to send the data to the PC comport ...All worked well!
A.Like this
16F887 (TX)----> (RX)18F4520(TX)------->MAX232--->PC COM PORT

B.When I changed things to this
18F4520 (TX)----> (RX)16F887(TX)------->MAX232--->PC COM PORT
the problem occurs.
Weird values at PC using MCS serial tool
Please also note this is if PIC's are WIRED together (not wireless)
In scenario B I check what the TX string is and it is what it's supposed to be in the serial tool window.
If I check at the 16F887 side in serial tool window I get incorrect values for the data received :-(

And that's what leads me to belive the problem lies at the 16F887 side .. but you may be right about the 18F4520 :-)
At this stage I would try almost anything to solve the problem

Kind regards
Dennis

PS.. Two fingers hey ? You're one up one me then :-) I'm like lightening on the keyboard ...never strike the same place twice :-)
**************UPDATE***************
On the transmitter PIC (18F4520) I am using this line

hserout [TRAIN,SYNK,XNUM,YNUM,ZNUM,$d,$a]

On the receiver PIC (16f887)
I use these two lines

hserin [WAIT(SYNK),XNUM,YNUM,ZNUM] ' (wait for synk byte)
hserout["X-",DEC XNUM," Y-",DEC YNUM," Z-",DEC ZNUM,$d,$a] 'to PC com port

If I remove this line

hserin [WAIT(SYNK),XNUM,YNUM,ZNUM] ' (wait for synk byte)

The I see data appearing in the serial tool window, obviously without the data I am sending.
So there seems to be a problem with HSERIN on the receiver PIC or what is being sent by the Transmitter PIC.

[Dennis]

Hello again

Try RCSTA = %10010000

Tried that ..still no luck.

By the way this is the 16f887 on the Pickit 2 44-pin demo board.

Regards
Dennis