Communication between two PicChip

[lerameur]

hello,

I am trying to transfer data from one Pic16F88 to another F88 chip. is there a method better then the other one. I only have 4 ports left (one is use for adcin, one for ground between the two chips and two for serin and serout). The only alternative I know but would cost a bit more is to use an external EEPROM..
I have A master program and a Slave program, here is the code, I think it is self explanatory:
PortB.7 is hooked up to the PortB.0 (interrupt) of the other chip

Master:

  SetRTCTime = 125
  ViewTime = 0

        I2CRead SDApin,SCLpin,$D0,$00,[RTCSec,RTCMin,RTCHour,RTCWDay,RTCDay,RTCMonth,RTCYear,RTCCtrl]  
        Pause 30
   

serout portb.7, n2400, [$55, $55, $55, $55, $aa, SetRTCTime, ViewTime, StartTimeHour ]
serout portb.7, n2400, [StopTimeHour, StartTimeMin, StopTimeMin, RTCYear, RTCMonth, RTCDay, RTCHour, RTCMin ]
Pause 100

            lcdout $FE,1,  "upload Time Int"
            lcdout $FE,$C0, "Completed"
            pause 1500
            
Return

Slave:

'/////////////////////////////
'/////// MyInterrupt  ////////
'/////////////////////////////
DISABLE
MyInterrupt:

waitfor55:
serin portb.0 , n2400 , temp : if temp <> $55 then goto waitfor55

waitforaa:
serin portb.0 , n2400 , temp : if temp <> $aa then goto waitforaa

serin portb.0, n2400, SetRTCTime : serin portb.2, n2400, ViewRTCTime
serin portb.0, n2400, StartTimeHour : serin portb.2, n2400, StopTimeHour
serin portb.0, n2400, StartTimeMin : serin portb.2, n2400,StopTimeMin
serin portb.0, n2400, Year : serin portb.2, n2400, Month
serin portb.0, n2400, Day : serin portb.2, n2400, Hour 
serin portb.0, n2400, Minute

If (SetRTCtime = 125) then
    I2CWRITE SDApin,SCLpin,$D0,$00,[$00,Minute,Hour,$00,Day,Month,Year,$00] ' Write to DS1307 to initialize a new time
    pause 30
Endif
 
If (ViewRTCTime = 55) then
    I2CRead SDApin,SCLpin,$D0,$00,[RTCSec,RTCMin,RTCHour,RTCWDay,RTCDay,RTCMonth,RTCYear,RTCCtrl]  
    Pause 30
    
serout portb.7, n2400, [$55, $55, $55, $55, $aa, SetRTCTime, ViewTime ]  'if 222 then
pause 200

serout portb.7, n2400, [$55,$55,$55,$55,$55,$aa,RTCYear, RTCMonth, RTCDay, RTCHour, RTCMin, RTCSec]
serout portb.7, n2400, [StartTimeHour, StopTimeHour, StartTimeMin, StopTimeMin]
pause 100

Endif


INTCON.1 = 0   ' Enable external Interrupt
RESUME
ENABLE                ' Enable Interrupt

The problem now is that the information is not transfering. And this is not a method to get a ACK and verify information transfered.

[Charles Linquis]

I think you are crazy to not use the HARDWARE serial port. That would make things almost trivial. Is there some reason why you aren't using it?

[lerameur]

Its takes three pins from my chip
: Serial Data Out (SDO) RB2/SDO/RX/DT
• Serial Data In (SDI) RB1/SDI/SDA
• Serial Clock (SCK) RB4/SCK/SCL

I am already using SDA and SCL to program and read my RTC. Unless I can use the same pin for both..

[aratti]

Why don't you use I2C also for the communication from pic to pic? Pic 16F88 can operate as slave, so you will give it an address and you will transfer all the data with I2CWRITE and I2CREAD, simpler than that! You can find a working code for I2C slave on the forum, I posted it sometime ago and I don't remember where is burried.

Cheers

Al.

PS. I found it! http://www.picbasic.co.uk/forum/show...ight=I2C+salve

[Charles Linquis]

When I mentioned hardware serial port, I was referring to TxD and RxD. Then you could use HSEROUT and HSERIN. Connect those two lines together on your PIC, and you can communicate at 9600 baud at least, on the internal oscillators.

[lerameur]

I just want to do a very simple communication at first, then I will work on better one. I am using the same code as i used a few ago for a project on mine. It was working fine at the time. I was using a different compiler and different software.
I am trying to re-use that code. Now I have taken THE code I used and just removed the extra stuff in the programming that is not needed ( calculation from a wireless thermometer) here is my sending code:

INCLUDE "modedefs.bas"
OSCCON = %01110000 '8 Mhz
Define OSC 8

CMCON = 7 : ANSEL = 0 : ADCON1 = 7
'/////////////////////////
'// LCD configuration //
'/////////////////////////

DEFINE LCD_DREG PORTA ' Set LCD Data port
DEFINE LCD_DBIT 0 ' Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_RSREG PORTB ' Set LCD Register Select port
DEFINE LCD_RSBIT 0 ' Set LCD Register Select bit
DEFINE LCD_EREG PORTB ' Set LCD Enable port
DEFINE LCD_EBIT 6 ' Set LCD Enable bit
DEFINE LCD_BITS 4 ' Set LCD bus size (4 or 8 bits)
DEFINE LCD_LINES 2 ' Set number of lines on LCD
DEFINE LCD_COMMANDUS 2500
DEFINE LCD_DATAUS 250
DEFINE CHAR_PACING 2000
pause 500

TRISB = %00000000

count_remain var byte
temperature1 var byte
temperature2 var byte

Mainloop:

temperature1 =11: temperature2 =22
count_remain =44



lcdout $FE,1, "TempC: ", dec (temperature1) , ".", dec2 temperature2," ",$DF,"C"
lcdout $FE,$C0, bin count_remain , ".","F"
pause 400

serout portb.2, n2400,[$55,$55,$55,$55,$aa,temperature1,temperature2,coun t_remain]

lcdout $FE,1 : LCDOUT "second ", dec (temperature2 / 100) , ".", dec2 temperature1," ",$DF,"r"
lcdout $FE,$C0, dec count_remain , ".","23"
pause 400

goto mainloop

end

and here is the receiving code:

INCLUDE "modedefs.bas"
OSCCON = %01110000 '8 Mhz
Define OSC 8

CMCON = 7 : ANSEL = 0 : ADCON1 = 7
'/////////////////////////
'// LCD configuration //
'/////////////////////////

DEFINE LCD_DREG PORTA ' Set LCD Data port
DEFINE LCD_DBIT 0 ' Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_RSREG PORTB ' Set LCD Register Select port
DEFINE LCD_RSBIT 0 ' Set LCD Register Select bit
DEFINE LCD_EREG PORTB ' Set LCD Enable port
DEFINE LCD_EBIT 6 ' Set LCD Enable bit
DEFINE LCD_BITS 4 ' Set LCD bus size (4 or 8 bits)
DEFINE LCD_LINES 2 ' Set number of lines on LCD
DEFINE LCD_COMMANDUS 2500
DEFINE LCD_DATAUS 250
DEFINE CHAR_PACING 2000
pause 500

ADCON1 = %00100010

encoded11 var word : encoded22 var word : encoded33 var word : encoded44 var word : encoded4 var byte
count_remain var byte :temp var byte


TRISA = %00000001 ' Set PORTA to all output
TRISB = %00001111


Mainloop:
'23

lcdout $FE,1 , "hello ", dec 105," ","C"
lcdout $FE,$C0, "before"
pause 300

waitfor55:
serin portb.2 , n2400 , temp : if temp <> $55 then goto waitfor55

waitforaa:
serin portb.2 , n2400 , temp : if temp <> $aa then goto waitforaa

serin portb.2, n2400, encoded11.HighBYTE : serin portb.2, n2400, encoded11.LowBYTE
serin portb.2, n2400, encoded22.HighBYTE


lcdout $FE,1, "encoded11.HighBYTE", dec encoded11.HighBYTE , ".", dec2 encoded11.LowBYTE
lcdout $FE,$C0, "TempF: ", "-", dec encoded22.HighBYTE , "After"
Pause 300


goto Mainloop

end

the sending code seems to work. but the receiving code seems to be stuck on the first LCDOUT, I guess it does not see the 55 or aa...

k