PIC16F877A TX data to PC via serial cable - Page 2 - Electronic Circuits Projects Diagrams Free

ericgibbs · 6th October 2007, 02:45 PM

Quote:

Originally Posted by derrick826

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
You wouldn't have these binaries in your PIC registers?You would have HiReg = 0x0, LoReg = 0xC0 ... 00,,1100,0000
I use the comma's just for clarity.

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?

hi,
It depends upon the receiving program in the PC, they can written to accept binary data, convert to ASCII then display.

The usual way is to do the binary to ASCII conversion in the PIC program and transmit ASCII characters,
in that way you can use any PC terminal program.

Which one do you use?

EDIT: just seen Nigels post,, are you planning to use ALL 10 bits or just 8??
At this time the program 'right justifies' the value.

**Nigel Goodwin** · 6th October 2007, 02:47 PM

Convert them to ASCII first, then send them.

It's dead simple to do - just add 0x30 to the value - check my LCD tutorial routines, subroutine 'CharD' which does just that for LCD.

derrick826 · 6th October 2007, 02:57 PM

alright Nigel! let me have a look

ericgibbs · 6th October 2007, 04:24 PM

hi,
As per our PM's

Simple example of OS Basic with asm conversion routines for your studies.

Code:

AllDigital

Define SIMULATION_WAITMS_VALUE = 1  'ignore sim delays

Define LCD_LINES = 4
Define LCD_CHARS = 16

Define LCD_BITS = 4
Define LCD_DREG = PORTD
Define LCD_DBIT = 0

Define LCD_RSREG = PORTE
Define LCD_RSBIT = 0

Define LCD_EREG = PORTE
Define LCD_EBIT = 2

Define LCD_RWREG = PORTE
Define LCD_RWBIT = 1

Define LCD_READ_BUSY_FLAG = 1


Dim ascbfr0 As Byte
Dim ascbfr1 As Byte
Dim ascbfr2 As Byte
Dim ascbfr3 As Byte
Dim ascbfr4 As Byte
Dim ascbfr5 As Byte
Dim ascbfr6 As Byte
Dim ascbfr7 As Byte

Dim b2avh As Byte
Dim b2avm As Byte
Dim b2avl As Byte

Dim hexval As Byte
Dim temp1 As Byte

Dim cntr1 As Byte
Dim cntr2 As Byte
Dim test0 As Byte
Dim test1 As Byte
Lcdinit

test0 = 0
b2avl = test0
hexval = test0

b2avm = 0
b2avl = test0

main:

test0 = test0 + 1
b2avl = test0
b2avm = 0


Gosub bin2asc5
Lcdcmdout LcdLine1Home
Lcdout ascbfr0, ascbfr1, ascbfr2,
Lcdout ascbfr3, ascbfr4, ascbfr5, ascbfr6, ascbfr7

Goto main

Gosub byte2asc3
Lcdcmdout LcdLine1Home
Gosub showme
Gosub hex2asc
ascbfr5 = 0x20
Lcdcmdout LcdLine2Home
Gosub showme

test0 = test0 + 1
b2avl = test0
hexval = test0
Goto main
End                                               

showme:

Lcdout ascbfr5, ascbfr6, ascbfr7
Return                                            

'convert 24 bit bin to 8 asci in ascbfr0 to 7
'or
'b2avh,b2avm,b2avl
'leading spaces in bfr
bin2asc5:
ascbfr0 = 0
ascbfr1 = 0
ascbfr2 = 0
ascbfr3 = 0
ascbfr4 = 0
ascbfr5 = 0
ascbfr6 = 0
ascbfr7 = 0

ASM:        bcf status,rp0
ASM:        bcf status,irp
ASM:        movlw 16  '24  ' bits
ASM:        movwf cntr1
bitlp:  'shift msb into carry
ASM:        rlf b2avl,f
ASM:        rlf b2avm,f
'ASM:        rlf b2avh,f
ASM:        movlw ascbfr7  '0=msd 1st
ASM:        movwf fsr  'fsr=pointer to digits
ASM:        movlw 5  '0x8  'digits to do
ASM:        movwf cntr2
adjlp:
ASM:        rlf indf,f  'shift digit 1 bit left
ASM:        movlw 0x0a
ASM:        subwf indf,W  'check and adjust for overflow
ASM:        btfsc status,c
ASM:        movwf indf
ASM:        decf fsr,f  'incf=msd 1st next digit
ASM:        decfsz cntr2,f
Goto adjlp
ASM:        decfsz cntr1,f  'next bit
Goto bitlp
ASM:        movlw 0x30  'make asci
ASM:        iorwf ascbfr0,f
ASM:        iorwf ascbfr1,f
ASM:        iorwf ascbfr2,f
ASM:        iorwf ascbfr3,f
ASM:        iorwf ascbfr4,f
ASM:        iorwf ascbfr5,f
ASM:        iorwf ascbfr6,f
ASM:        iorwf ascbfr7,f
ASM:        movf ascbfr0,w  'blank leading zeros
ASM:        andlw 0x0f
ASM:        btfss status,z
Return                                            
Return                                            
ASM:        bcf ascbfr0,4  'make dig spc
ASM:        movf ascbfr1,w
ASM:        andlw 0x0f
ASM:        btfss status,z
Return                                            
ASM:        bcf ascbfr1,4
ASM:        movf ascbfr2,w
ASM:        andlw 0x0f
ASM:        btfss status,z
Return                                            
ASM:        bcf ascbfr2,4
ASM:        movf ascbfr3,w
ASM:        andlw 0x0f
ASM:        btfss status,z
Return                                            
ASM:        bcf ascbfr3,4
ASM:        movf ascbfr4,w
ASM:        andlw 0x0f
ASM:        btfss status,z
Return                                            
ASM:        bcf ascbfr4,4
ASM:        movf ascbfr5,w
ASM:        andlw 0x0f
ASM:        btfss status,z
Return                                            
ASM:        nop
Return                                            



hex2asc:
ASM:        movf hexval,w
Gosub hex1
ASM:        movwf ascbfr7
ASM:        swapf hexval,w
Gosub hex1
ASM:        movwf ascbfr6
Return                                            
hex1:
ASM:        andlw 0x0f
ASM:        addlw 0x30
ASM:        movwf temp1
ASM:        movlw 0x3a
ASM:        subwf temp1,w
ASM:        btfss status,c
Goto hex2
ASM:        movf temp1,W
ASM:        addlw 0x7
Return                                            
hex2:
ASM:        movf temp1,W
Return                                            

'leading zero's displayed
byte2asc3:
ASM:        movlw 0x0
ASM:        movwf ascbfr5
ASM:        movwf ascbfr6
ASM:        movwf ascbfr7
ASM:        bcf status,rp0
ASM:        bcf status,rp1
ASM:        bcf status,irp
ASM:        movlw 0x8
ASM:        movwf cntr1
binlp1:
ASM:        rlf b2avl,f
ASM:        movlw ascbfr7
ASM:        movwf fsr
ASM:        movlw 0x3
ASM:        movwf cntr2
binlp2:
ASM:        rlf indf,f
ASM:        movlw 0x0a
ASM:        subwf indf,w
ASM:        btfsc status,c
ASM:        movwf indf
ASM:        decf fsr,f
ASM:        decfsz cntr2,f
Goto binlp2
ASM:        decfsz cntr1,f
Goto binlp1
ASM:        movlw 0x30
ASM:        iorwf ascbfr7,f
ASM:        iorwf ascbfr6,f
ASM:        iorwf ascbfr5,f
Return

derrick826 · 8th October 2007, 01:11 PM

Hi there Eric.. i have tried the codes for data transmission to the PC via the serial cable and it works... thanks for your help and the PIC simulator IDE really helps..

may i know what can the tools (from PIC simulatior IDE) software UART simulation interface and the PC's serial port terminal do? When i simulate the sample coding you provided me in the previous post.. there are no results on both the tools

Are the tools (software UART simulation interface and the PC's serial port terminal ) related to the hardware UART simulation?

ericgibbs · 8th October 2007, 02:10 PM

hi,

Quote:

Originally Posted by derrick826

Quote:

may i know what can the tools (from PIC simulatior IDE) software UART simulation interface and the PC's serial port terminal do? When i simulate the sample coding you provided me in the previous post.. there are no results on both the tools

Its the 'hardware UART simulation tool when testing the PIC sim internal UART programs, NOT the software or PC.

Are the tools (software UART simulation interface and the PC's serial port terminal ) related to the hardware UART simulation?

The software simulator is when you write a program that uses PIC bit switching for the "uart" and not the PIC's internal UART

The PC's 'serial port terminal' is a utility program for using the PC's RS232, its not interlinked with the OS sim pins.

Does this help?

derrick826 · 8th October 2007, 02:28 PM

yea i think this answers the questions.. thanks eric!

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6th October 2007, 02:47 PM	(permalink)
Nigel Goodwin	Convert them to ASCII first, then send them. It's dead simple to do - just add 0x30 to the value - check my LCD tutorial routines, subroutine 'CharD' which does just that for LCD. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

6th October 2007, 02:57 PM	(permalink)
derrick826	alright Nigel! let me have a look

8th October 2007, 01:11 PM	(permalink)
derrick826	Hi there Eric.. i have tried the codes for data transmission to the PC via the serial cable and it works... thanks for your help and the PIC simulator IDE really helps.. may i know what can the tools (from PIC simulatior IDE) software UART simulation interface and the PC's serial port terminal do? When i simulate the sample coding you provided me in the previous post.. there are no results on both the tools Are the tools (software UART simulation interface and the PC's serial port terminal ) related to the hardware UART simulation?

8th October 2007, 02:28 PM	(permalink)
derrick826	yea i think this answers the questions.. thanks eric!