hi again guys,

I'm facing another problem regarding on the Transmission of datas from my PIC to PC via the serial cable. Currently I'm using the RS232 model circuit taken accordingly from Nigel_goodwin's tutorial, a serial cable to connect to the PC (male to female converter) and of course the PIC to trasmit the data. I'm sending the data through RC6/tX. And my coding goes like this:

__config _CP_OFF & _PWRTE_ON & _XT_OSC & _WDT_OFF

ERRORLEVEL -302 ;Suppress bank warning


org 0x000
goto start

int org 0x004
goto int


start

CALL INITIAL
START1
CALL SEND
CALL CHECK
GOTO START1



SEND
MOVLW B'10010000'
MOVWF TXREG
RETURN

INITIAL
BCF STATUS,RP1
BSF STATUS,RP0
MOVLW B'00000000'
MOVWF TRISB
MOVLW h'24'
MOVWF TXSTA
MOVLW D'129'
MOVWF SPBRG
movlw B'10000000'
movwf TRISC
BCF STATUS,RP0
BSF RCSTA, SPEN
RETURN




CHECK
MOVLW B'00010000'
MOVWF PORTB
ONEMORETIME
BTFSS PIR1,TXIF
GOTO ONEMORETIME
MOVLW B'10000000'
MOVWF PORTB
RETURN


END

i'm actually relooping so that i'm constantly sending b'10010000' (90 in hexa). Since the start bit starts at the LSB therefore the data that is transmitting will be

(startbit) 0 00001001 1 (stop bit)

Am i sending a data '09' in hexa?

i'm using a MATLAB program to receive these particular data and it doesn't seem to respond even though i send a data from my PIC. this particular data has gone through the rs232 for voltage conversion 12V and to the female serial cable which then goes into the male serial of the pc. When i measure the voltage out from the rs232.. it seems to be 20V.. not 12V.

I'm trying out one of Nigel's tutorial regarding on the rs232 thingy but I don't really know what program to use to check weather or not the data which is being trasmitted from my PIC is being display on the PC. Is there any specific program to display the results i sent?

hope you guys are able to give me some hint and help so that i know where to start. thanks in advance

 

Use HyperTerminal on the PC, make sure you set it to the correct speed etc. and no handshaking.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

hi Nigel_Goodwin,

i had already select the correct configuration

baud rate 9600
data bits 8
stopbits 1
parity none
flow control "hardware" for Hyper terminal, for normal situation we use none

but still no sign of improvement.. the PC receives 12V.. but when it receives a 20v data.. surely it cannot read.. Is there any configuration needed for PIC to link with RS232 when sending data?

isn't it the purpose of the Rs232 is to convert my signal data voltage into a voltage suitable for the PC to be received

 

Hi Derrick826,

Try to simulate first with this software http://www.oshonsoft.com/pic.html .It's good software, if its ok with simulator so its ok too with your real device. I always use this trick and working great.

Thanks

__________________
http://www.henryelectronics.com

 

yea thanks for the program i'm trying to figure out how to use it

 

It won't work with hardware handshaking, you must set flow control to none.

Also make sure you have TX and RX connected correctly, depending what type of lead you are using (either straight or crossover).

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

hi,
Your program will not run, number or errors.

Tried in Oshonsoft, generates errors in hardware uart sim.

Posted a simple uart program for you to try out, it works in Sim and PIC

If you need any guidance using Oshonsoft, will be pleased to help.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

ok Nigel... i will try it out and let you know my progress.... thanks for your help. But i was little worried about my coding if it's incorrect. So far i'm able to simulate it.

thanks for your help again!

 

hi eric..

can you tell me briefly what does the ser1x.asm program do?
I have tried my program in the Oshonsoft too using the both the hardware and software of uart sim... but there's nothing happening...

what has gone wrong with my codings if i may ask?

 

hi,
The program is set for 9600 baud, 1 start bit, no parity, 1 stop bit.
It transmits "UART" and then <crlf> for a new line.
then a 100mSec delay and repeats.

In the Sim set the xtal for 4MHz, PIC as 16F877.
Use the TOOLS menu to select 'hardware uart'

Assemble the program using 'F9' keyboard key.
Use Sim 'FILE' menu to LOAD the serx1.hex

Start the simulation.



Select 'Rate' as Ultimate

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

hi,
Screen shots of my settings.


EDIT: added some notes for sim.

Sequence:

Start Sim
Set PIC type
Change Clock Frequency
Tools/Hardware UART sim interface
Tools/Assembler
... paste in serx1.asm to assembler Window

From Assembler Menu/Tools/Assemble with MPASMWIN [ or 'F9']
.. wait for asm to finish

From PIC Sim Menu/File/Load Program
... load the serx1.hex

Menu/Rate/Ultimate [top speed]

Menu/Simulation/Start

NOTE: I usually shorten the LOOPMS delays to 0.1 before I assemble and load, else
you could wait ages for a 100mSec delay in the Sim.

Tip:
From PIC/Sim
Menu/Options/Change UART Transmit/Receive time...... SET to '50'

For future ref when using LCD Module,
From LCD Module Menu
Click SetUp
Click 'Setup LCD Module Busy delays'
Change the '1640' default to about 100, you will get a faster update on the LCD.

---------------
Extract from manual: use this to switch your delays On and Off
So, just for the purpose of simulation you should recompile your programs with adjusted delay intervals,
that should not exceed 1-10ms.

But, be sure to recompile your program with original delays before you download it to a real device.

There is an easy way to change arguments of all WAITMS statements in a large basic program with a value
in the range 1-10 for simulation purposes.

With one line of code setting parameter SIMULATION_WAITMS_VALUE with DEFINE directive,
the arguments of all WAITMS statements in the program will be ignored and the specified value will be used instead during compiling.

Setting the value 0 (default) for this parameter (or omitting the whole line) will cancel its effect and the compiled code will be ready again for the real hardware.
-------------------------

DEFINE SIMULATION_WAITMS_VALUE = 1; delays ignored,,,, change to '1' before you program a PIC !

Hope this helps.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

yea the hardware uart display UART..... but may i ask... in real life what's the 'hardware uart'

does this hardware uart displays these alphabets? what if i were to transmit this character to the PC?

this coding:

MOVLW .13 ;crlf
CALL TXRDY
MOVLW .10
CALL TXRDY

is similar to the other:

MOVLW 'U'
CALL TXRDY

but why doesn't it displays the numbers?


i'm sorry Eric... there's some coding here which i'm not really familiar with:

LOOPMS MACRO MSEC
MOVLW MSEC
MOVWF WAITL
CALL WAITLOOP
ENDM

;
;
;
;


LOOPMS .100 ;100mS delay after each line
;
;
;
;


WAITLOOP:
CALL DEL1MS
DECFSZ WAITL,F
GOTO WAITLOOP
RETURN
DEL1MS: ; 1ms delay loop
MOVLW 0X64;100*10US=1MS
MOVWF CNTR0
DL2:
NOP
NOP
NOP
NOP
NOP
NOP
NOP
DECFSZ CNTR0, F
GOTO DL2
RETURN

i'm not familiar with the LOOPMS MACRO MSEC

the code : LOOPMS .100 (actually means that the LOOPMS having the value of 100?)

and then the code : LOOPMS MACRO MSEC (means that the MSEC contain the value of 100 from LOOPMS?)

so sorry Eric that you have to help me with this.. i'm kinda slow.. and i have ask a lot of nonsense...

 

Because they are the ASCII characters for CR and LF, so the PC will perform those tasks, and merely move the cursor and scroll the screen (if required).

It's a MACRO, it generates code during the assembler process and inserts a value (MSEC).

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Dont worry about being slow, wev'e all been there!

Have a look at your other thread [ADC] just posted info.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

thanks guys!

Eric.. if let's says in this case we are actually transmitting in ASCII characters.
i have an ultrasonic circuit which displays a measurement value on the 7 segment LED , example 192 which my register:

display_H = 00000001
display_T = 00001001
display_U = 00000010

has these 8-bit in binary
is there anyway which i can do to trasmit this 8-bit binaries to allow the PC to display 192 on the screen?