Do i have to use max232??

When i am trying to send data pic to another pic do i have to use MAX232?
coz i am trying these codes and not working....

'''''''''''''''''''MASTER
include "modedefs.bas"
define CHAR_PACING 100
DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTD
DEFINE LCD_RSBIT 0
DEFINE LCD_EREG PORTD
DEFINE LCD_EBIT 1
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50
adcon1=7
t1 var word
t1=0
basla:
t1=0
lcdout $fe,1
lcdout "counter"
loop:
if portb.0=0 then goto birinci
goto loop
birinci:
serout porte.0,5,[1,13]
serin porte.1,5,30,gel1,#t1
gel1:
lcdout $fe,1
lcdout "counter",
lcdout $fe,$c0
lcdout "count:",#t1
pause 2000
goto basla
end


''''''''''''''''SLAVE
include "modedefs.bas"
define CHAR_PACING 100
CMCON = 7
TRISA =%11111111
b0 var byte
b0=0
COUNTER var word
COUNTER = 0
b1 var byte
b1 =0
DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 0
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 3
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50
sil:
COUNTER=0
lcdout $FE, 1
lcdout "COUNTER"
lcdout $fe,$c0
lcdout "COUNT:"#COUNTER
loop:
serin portb.1,5,10,kontrol,B0
if b0=1 then goto ok
goto kontrol
goto loop
kontrol:
button porta.4 ,0,255,255,b1,1,goster
goto loop
goster:
COUNTER = COUNTER + 1
lcdout $FE, 1
lcdout "COUNTER"
lcdout $fe,$c0
lcdout "COUNT:"#COUNTER
goto loop
ok:
pause 20
serout portb.2,5,[#COUNTER,13]
lcdout $FE, 1
lcdout "COUNTER"
lcdout $fe,$c0
lcdout "COUNT SEND"
pause 1000
GOTO sil
END


SLAVE = 16F628 have a button on porta.4
MASTER=16F877 have a button on portb.0

Hello Sub Zero,

SZ>>When i am trying to send data pic to another pic do i have to use MAX232?<<

No, you do not... your signal does not need to be inverted or anything like that.

Take a look at the following:

http://www.picbasic.co.uk/forum/showthread.php?t=579


Remember, take one step at a time... Can you verify your output with a scope? Can you verify data is being sent? Nothing like attempting to send data on a port that is not capable... like Porta.3 which is a input for some chips. <g>

Dwayne

I did all of them but not working.
1. Make sure your Pins that you are using are I/O pins.
2. Make sure your chip is running (MCLR not on Reset)
3. Make sure there is no noise between the two pins. You may need a Resistor to Ground for this.
4. Make sure you are using the simplest of the SerOut commands. No "Additives" yet!... Got to get the basics going first.
5. Use the same Baud Rates, and use a SLOW Baud rate.
6. Its best to use the same Clock speed at first, until communications has been established.

2.do u mean i will not connect a resistor to mclr?(on both pics?)
3.do u mean i must connect TX and RX to ground with a resistor like 1 K?

Have a look at PBP Manual Sections 5.68 & 5.70

Code:

---

serin porte.1,5,30,gel1,#t1
gel1:

---

Doesn't make much sense

i change the commands like u re suggestion
like this
serout porte.0,5,[1,13]
serin porte.1,5,t1
but this time nothing works
:(

I'm sorry Sub,

I did not suggest to change it to what you have changed it to,

I suggested to have a look at the Manual !

I really don't undestand in proteus simulation program it say's it is working i set up the circuit in the real world and it is not working :( i looked every connection and there is no mistake it must work 16F628 and 16F877 are working 4 mhz i remove the mclr resistors and i put resistors to the serin and serout pins that has been connected to the ground i use little commands. I do everything that u write or another friend write or PBP manuel or another book writen in Turkey.I am losting my hope :(
PLEASE LOOK AT THE PICTURES.
''''''''''''''''''16F628 PROGRAM CODES
include "modedefs.bas"
define CHAR_PACING 100
CMCON = 7
TRISA =%11111111
b0 var byte
b0=0
COUNTER var word
COUNTER = 0
b1 var byte
b1 =0
DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 0
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 3
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50
sil:
COUNTER=0
lcdout $FE, 1
lcdout "COUNTER=" , #COUNTER
lcdout $fe,$c0
lcdout #COUNTER

loop:
serin portb.1,5,10,kontrol,B0
if b0=1 then goto ok
goto kontrol
goto loop

kontrol:
button porta.4 ,0,0,0,b1,1,goster
goto loop

goster:
COUNTER = COUNTER + 1
lcdout $FE, 1
lcdout "COUNTER=",#COUNTER
goto loop

ok:
pause 20
serout portb.2,5,[#COUNTER,13]
lcdout $FE, 1
lcdout "COUNTER=" , #COUNTER
lcdout $fe,$c0
lcdout "SENT!!!"
pause 1000
GOTO sil

end

'''''''''''''''''''''''16F877 PROGRAM CODES
include "modedefs.bas"
define CHAR_PACING 100
DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTD
DEFINE LCD_RSBIT 0
DEFINE LCD_EREG PORTD
DEFINE LCD_EBIT 1
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50
adcon1=7

t1 var word
t1=0

top var word
top=0

basla:

t1=0
top=0

lcdout $fe,1
lcdout "CHOSE"
loop:
if portb.0=0 then goto birinci
goto loop

birinci:
serout porte.0,5,[1,13]
serin porte.1,5,30,gel1,#t1
gel1:
top=t1*10
lcdout $fe,1
lcdout "COUNTER=",#t1
lcdout $fe,$c0
lcdout #top
pause 2000
goto basla
end

quick test, remove all your timeout label, delay and such and redo the test.
if it's working, increase them.

case not... i'll prefer to use the internal USART.

The problem might be much simpler than you think!
1)Are those PICs on separate PCBs?
2)Do they have separate power supplies?

My Idea is if the answers are yes and no then you should join the grounds together. You must join the pics with the signal wire and a ground wire.

When I was younger and just started with electronics that was my problem, I connected the ground and everything started to work!!

Hello SubZero,

I would start as Steve says...Remove all.

I would do the following... In somewhat this order.

1. The slave (receiving chip).

(WITHOUT USING SERIN)

1. Blink a light on each of the pins that will control your LCD. (Portb).

You can do this by the following psuedo code:

TRISB=%00000000 ' assigning all Portb as output.
Loop:
port b=255
pause 100
portb=0
pause 200
goto Loop

this verifies that your Slave chip is working correctly on the output, and it gives you confidence that your LCD will be driven by all pins of Port B. It is not a GUARANTEE, but a big vote of confidence.

2. Attach LCD and (WITHOUT USING SERIN) Print "Hello Word" on the LCD.

This gives you the confidence that the Slave IS working, and that the LCD IS working...


If either of the above 2 things I have said cannot be done... you had better drop everything and MAKE the above two things happen!...Either that, you are wasting your time.


Master Chip.

Same as above.. You had better BLINK the LED's on the pins you are using to send... If you use PortA.0, you had better be able to BLINK a LED on PORTA.0!!!! If you can't blink a LED on PortA.0, then don't go ANY FURTHER!!!! Why is it not blinking??? Is it because you didn't turn off the comparitors? Assign it to Digital? Use the proper TRISA of %00000001 ?

IF the pin you are going to use, blinks a LED, lets go to the next step

Use the simplist of ALL SEROUT commands.... instead of going though the next steps, that link I gave you will take you through using the SEROUT and scoping it.

==================

Now, with master chip working... lets reprogram the Slave with a SERIN command... no thrills.... just like the link....

=====================

You should be able to get communication between the chips...from here on, you add LITTLE by LITTLE, and fall back upon something that WORKS.

Try adding a timeout label and loop it back...make sure it works...

============================

Remember, you are experiementing, and sometimes its better to take a small nibble off that loaf of bread, than biting off more than you can chew or swallow.

Many times I have reverted to the Nibble technic...In programming, I sometimes look through 200,000 lines of code...Much if it I can ignore...But when that paticular "error" or "failure" occures, I must sometimes look through each line of code, and sometimes each variable of each line!

Dwayne

print hello to the LCD.