Can PBP & 16f88 really do 9600,8,E,1

[retepsnikrep]

I have an 16f88 project which needs to communicate with an rs485 bus.

The bus is fixed and I can't change the protocols so I need to be able to rxd & txd via the usart 9600,8,E,1 data.

Can hserout/hserin or serin/out really do 8 data bits & an even parity bit?

11 bits in all inc a start & stop bit.

I know the pic usart can do 9 bit data transmission but it is not 100% clear I can do what I need in PBP without poking registers and driving the usart directly.

Can someone give me a definitive answer? Any useful links would be great as well. I'm happy with the electronics side of this project, it's the pbp serial commands which are confusing me.

[dhouston]

Have you read the manual entry for HSERIN? It has DEFINES for 8 bits + parity and for odd or even parity.

EDIT: My print manual lists DEFINE HSER_BITS 9 (Use 8 bits + parity) for both HSerIn and HSerIn2 but, it is omitted in the online manual at MELabs

• http://www.melabs.com/resources/pbpm...7-5_29.htm#528

[muddy0409]

I have very successfully used an 'F88 at 9600. Used a 20MHz crystal and used debug / debugin rather than the normal serout stuff. No probs at all (so far)

[dhouston]

µeLabs Support tells me the online version of the manual is out of date. So you should be able to do what you need with...

DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 20h
DEFINE HSER_BAUD 9600
DEFINE HSER_EVEN 1
DEFINE HSER_BITS 9

[retepsnikrep]

My first 16f88 code is here. Microstudio says it compiles correctly. I now need to try and load it into the pic!!

It should recieve 12 bytes of 9600,8,E,1 data via Usart RX the then squirt it out the other side via Usart TX.

Any glaring errors or ommisions?

'-------------------------------------
' PBP Fake BCM CODE 21/10/09 V.04
'-------------------------------------

@ DEVICE PIC16F88,INTRC_OSC_NOCLKOUT
@ DEVICE PIC16F88,PROTECT_OFF
@ DEVICE PIC16F88,WDT_OFF
@ DEVICE PIC16F88,PWRT_ON
@ DEVICE PIC16F88,MCLR_OFF
@ DEVICE PIC16F88,BOD_OFF
@ DEVICE PIC16F88,LVP_OFF
@ DEVICE PIC16F88,CPD_OFF
@ DEVICE PIC16F88,DEBUG_OFF
@ DEVICE PIC16F88,CCPMX_OFF

DEFINE OSC 8 ; set oscilator speed to 8mHz 
DEFINE HSER_BAUD  9600
DEFINE HSER_BITS 9
DEFINE HSER_EVEN 1
DEFINE HSER_CLROERR 1 ; Clear overflow automatically

OSCCON=%01111000 '8 Mhz
ANSEL = 0 'ALL DIGITAL
CMCON = 7 'COMPARATORS OFF
INTCON = 0 ;Disable interrupts
TRISB = %00000100 ;RB2(RX) as input, others to Output
TRISA = %11111111 ;SET PORTA AS INPUTS

PORTB.4 = 1
DATAIN VAR BYTE[12]
loop 
HSERIN [str DATAIN\12]
HSEROUT [str DATAIN\12] 
goto looP
END

[dhouston]

loop should be loop:

And you have omitted

DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 20h

[retepsnikrep]

Dave

Thanks for that!

However I saw this earlier post which seems to imply the defines you mention are not required??

http://www.picbasic.co.uk/forum/show...=hserin+parity

[dhouston]

Ahhh! I should have looked at RXSTA & TXSTA in the datasheet. The PBP docs are a bit too cryptic at times.

[retepsnikrep]

Thanks I've made some changes to my code and it is working sort of.

'-------------------------------------
' PBP Fake BCM CODE 21/10/09 V.04
'-------------------------------------

@ DEVICE PIC16F88,INTRC_OSC_NOCLKOUT
@ DEVICE PIC16F88,PROTECT_OFF
@ DEVICE PIC16F88,WDT_OFF
@ DEVICE PIC16F88,PWRT_ON
@ DEVICE PIC16F88,MCLR_OFF
@ DEVICE PIC16F88,BOD_OFF
@ DEVICE PIC16F88,LVP_OFF
@ DEVICE PIC16F88,CPD_OFF
@ DEVICE PIC16F88,DEBUG_OFF
@ DEVICE PIC16F88,CCPMX_OFF

DEFINE OSC 8 			'Set oscilator speed to 8mHz 
DEFINE HSER_BAUD  9600		'Set Baud rate to 9600bps
DEFINE HSER_BITS 9		'Set to 9 bit mode
DEFINE HSER_EVEN 1		'Set Even Parity
DEFINE HSER_CLROERR 1 		'Clear overflow error automatically

OSCCON=%01111000 		'8 Mhz
ANSEL = 0 			'ALL DIGITAL
CMCON = 7 			'COMPARATORS OFF
INTCON = 0 			'Disable interrupts
TRISB = %00000100 		'SET PORTB RB2(RX) as input, others to OUTPUT
TRISA = %11111111 		'SET PORTA AS INPUTS

DATAIN VAR BYTE[12]		'Define DATAIN as a byte array (12 Bytes)  

loop: 				'Start of Communications Loop
HSERIN [str DATAIN\12]		'Receive 12 bytes into array DATAIN
HSEROUT [str DATAIN\12]		'Transmit 12 bytes from array DATAIN
goto looP			'Goto Loop

END

Now what I want to do is use a qualifier so that the Hserin waits until $AA is received before it starts filling the array. I also want the $AA in the array though? Possible?

So it should receive twelve bytes in all like this.

0xAA,0x10,0x00,0x00,0x00,0x20,0x40,0x61,0x10,0x01, 0x00,0x74

Does this look right?

loop: 				'Start of Communications Loop
HSERIN [WAIT($AA), str DATAIN\12]		'Receive 12 bytes into array DATAIN  
HSEROUT [str DATAIN\12]		'Transmit 12 bytes from array DATAIN
goto looP			'Goto Loop

I read that a delay may be required after the last send in the HSEROUT section or it may not transmit the last byte correctly?

[retepsnikrep]

Thanks for those comments.

Any idea why this line won't compile?

HSERIN [WAIT($AA), str DATAIN\11]		'Receive 11 bytes into array DATAIN

I want it to wait until a $AA appears before filling the array.

I've tried square brackets, round brackets no $ etc etc!!!!!

I get two errors bad expression and expected ]

[ScaleRobotics]

That compiles for me (but micro code studio forces the capitalization of STR). However, since you are using asci, try adding quotes on your $AA

HSERIN [WAIT("$AA"), STR DATAIN\11]		'Receive 11 bytes into array DATAIN

[retepsnikrep]

Try adding quotes on your $AA

HSERIN [WAIT("$AA"), STR DATAIN\11]		'Receive 11 bytes into array DATAIN

Tried that still get error expected ], tried sqaure brackets same result + syntax error

[ScaleRobotics]

Tried that still get error expected ], tried sqaure brackets same result + syntax error

I will get the same error, but only if I do not define DATAIN array before the wait line.

[dhouston]

I don't see what is causing the syntax error.

There is a sample program that shows various inputs using SerIn here...

• http://www.melabs.com/resources/samples/pbp/ser2mod.bas

I believe HSerIn uses the same syntax.

Also, lose the quote marks - you are waiting for $AA (i.e. 0xaa, a hex byte, binary %10101010) not ascii AA which would be "AA" without the $.

[retepsnikrep]

Nope still no joy won't compile.

Just to clear up any confusion I'm waiting for a byte value to appear on the usart ($87) not an ascii string. I then want to gather the following data into the array. It's 9600 8,E,1 (24 bytes total in the packet inc the $87 start byte)

This compiles

HSERIN [WAIT ($87)]		'Wait for byte $87 (135 Dec)

as does this

HSERIN [WAIT (135)]		'Wait for byte $87 (135 Dec)

Looks like I will have to wait for the identifier then use another HSERIN command to get the following bytes. Problem is there is no break in the data and it follows on immdiately after the $87 if received. I hope it doesnt miss the start of the second byte

I'll try this it compiles corectly.

HSERIN [WAIT ($87)]		'Wait for packet start Byte $87  
HSERIN [STR BCMDATA\23]		'Receive following 23 bytes into array BCMDATA