USART problems

[Demon]

That's perfect Bruce! Thanks!

I read a tutorial on controlling the DB9 pins directly, modem style, and I was going nowhere fast. Your technique is much better, I had read about it earlier but I didn't know how to tie it all together. And best of all, it uses USART instead of SERIN2.

Yup, I had an asterisk as end of record marker, but I like tilde even better. There's no chance at all that it will appear in the text so it makes a better choice.

I don't really care about telling the PC to stop sending, but I'll keep your solution in mind. My main goal was just to download a file onto EEPROM, once complete, I didn't really care about cleaning up. This will be used for one-shots, once the data is on the EEPROM, I don't alter the data.

Welp, I'm off to try this. If I got it right; MAIN is the USART I/O routine, DOODLE is waiting for input and OUTMSG is an end of record summary.

Robert


Stupidlesser as each day goes on...

[Demon]

Bruce,

Can you PM or email me your last name please?

roberthedan AT hotmail DOT com

I'd like to give credit where credit is due in the comments.

And you've also made yourself a new customer at Rentron.

Robert

[Demon]

On Interrupt Goto Main
GOTO Doodle

Disable
Main:
WHILE RCIF ' If RCIF=1 there's a new character in RCREG
BytesIn[ByteCnt]=RCREG ' Yes. Then store it in array
If BytesIn[ByteCnt]=EOM then OutMsg ' Display on receipt of terminating char
ByteCnt=ByteCnt+1 ' Increment array index pointer
WEND ' Exit only when RCREG is clear
RESUME ' Return to normal operation prior to interrupt
ENABLE

---------------------------------------------------

Isn't DISABLE an unexecutable statement? Shouldn't it be the 1st statement of Main?

Then at the bottom of OutMsg, we could GOTO the WHILE statement as it is doing now; label Main1 on Disable, and Main2 on While?

Or am I missing something?

Robert

[mister_e]

Hi Robert,

NOP, see PBP manual. Interrupt handler must be write like this. I agree that it looks weird but compiler handle it for you.

[Demon]

The compiler is wrong, and I am right...

Robert

[Demon]

Bruce, your code works perfectly when I process a single record. But I'm trying to add a paragraph at the bottom to read multiple records and failing miserably. I'm sure I'm screwing up the INTERUPT controls. As it stands, RESUME returns into the Doodle paragraph and stays there until my hair falls out (which will be soon).

I tried to add ON INTERUPT immediately before the Doodle, followed by an INTCON=$80, but I must be messing something up doing that. I want the interupts to happen ONLY during the Doodle logic. I don't want it to fire up while I'm in the middle of extracting the bytes from BytesIn and writing them onto the EEPROM.

Also, when you 'Trash any left over characters in RCREG buffer, I will be losing characters from the next record. I have to save that in a temporary array and load it back at the start of BytesIn somehow.

Robert

[Demon]

Ok,

I started again from your code, and modified one thing at a time. I've removed the comments to make it easier to read here (I figure you don't need your own comments).

1. I saved the data from the 1st record by copying it into BytesGP[ByteGPN]. I need that data so I can write it to the EEPROM.

2. I was able to get just Doodle under Interupt control.

3. I was able to save the data from RCREG. There was indeed the 1st character from the next record in there. The data is stored in BytesBK[ByteBKN].

?. But I can't figure out what I'm doing wrong to get the rest of the 2nd record. I must be losing some kind of flag or something to tell USART not to hyperspace the rest of the 2nd record.

====================================
define LOADER_USED 1
ASM
LIST
INCLUDE 'M16F87X.INC' ; PM header
DEVICE PIC16F877, HS_OSC, WDT_OFF, PWRT_ON, BOD_ON, LVP_OFF, CPD_OFF, WRT_OFF, DEBUG_OFF, PROTECT_OFF
XALL
NOLIST
ENDASM
define OSC 20
define HSER_BAUD 19200
DEFINE HSER_CLROERR 1
DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 24h

GP VAR BYTE
BytesIn var byte[80]
ByteCnt var byte
BytesGP VAR BYTE[80]
ByteGPN VAR BYTE
BytesBK VAR BYTE[80]
ByteBKN VAR BYTE
X VAR BYTE
EOM CON "~"
OERR VAR RCSTA.1
CREN VAR RCSTA.4
RCIF VAR PIR1.5
ByteCnt = 0
ADCON1 = 7
INTCON = %11000000
PIE1.5 = 1
' -------------------------------------------------------------
GOTO Start
' -------------------------------------------------------------
Main:
WHILE RCIF
BytesIn[ByteCnt]=RCREG
If BytesIn[ByteCnt]=EOM then OutMsg
ByteCnt=ByteCnt+1
WEND
RESUME
' -------------------------------------------------------------
OutMsg:
HSEROUT [13,10,dec ByteCnt," Bytes Rcvd:",STR BytesIn\ByteCnt]
FOR GP=0 to ByteCnt
BytesGP[GP]=BytesIn[GP]
BytesIn[GP]=0
NEXT
ByteGPN=ByteCnt-1
ByteCnt=0
ByteBKN=0
WHILE RCIF
BytesBK[ByteBKN]=RCREG
ByteBKN=ByteBKN+1
WEND
GOTO Main
' -------------------------------------------------------------
On Interrupt Goto Main
Doodle:
FOR X = 0 TO 250 : PAUSEUS 20 : NEXT X
FOR X = 0 TO 250 : PAUSEUS 20 : NEXT X
RETURN
INTCON=$80
' -------------------------------------------------------------
Start:
ByteGPN=0
WHILE ByteGPN=0 : GOsub Doodle : Wend
'''''''''''''''''''''''''''''''''''''''''''''''''' '''''''''''''
' BytesGP[ByteGPN] Data from BytesIn is saved here for EEPROM
'''''''''''''''''''''''''''''''''''''''''''''''''' '''''''''''''
' Place contents trashed from RCREG back in beginning of BytesIn
ByteCnt=ByteBKN-1
For X=0 TO ByteCnt
BytesIn[X]=BytesBK[X]
NEXT X

HSEROUT [13,10,dec ByteCnt," Bytes Saved:",STR BytesIn\ByteCnt]
GOTO Start
' -------------------------------------------------------------
end