Help for my project(16f877,2x16LCD,)

**karamastik** · - 21st March 2008, 20:37

Hello

I'm using 16f877;
i changed the lcdout command like yours and
here , i checked for the ADC reading:

@ DEVICE pic16F877
@ DEVICE pic16F877, WDT_on
@ DEVICE pic16F877, PWRT_ON
@ DEVICE pic16F877, PROTECT_OFF
@ DEVICE pic16F877, HS_OSC

DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTE
DEFINE LCD_RSBIT 1
DEFINE LCD_EREG PORTE
DEFINE LCD_EBIT 0
DEFINE LCD_RWREG PORTE
DEFINE LCD_RWBIT 2
DEFINE LCD_BITS 8
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 1000
DEFINE LCD_DATAUS 225
DEFINE ADC_BITS 10
DEFINE ADC_CLOCK 2
DEFINE ADC_SAMPLEUS 100

bar var byte
raw var word
I var byte

trisa=1
trisb=0
trise=0

lcdout $FE,$40,0,$1F,$1F,$1F,$1F,$1F,$1F,0,$fe,1
ADCON1=$8e
PAUSE 200
ADCIN 0,raw
bar=(1023-raw)/64
for I=1 to bar
lcdout dec3 raw
next I
END

there is a 16 digit number : 2732732732732732 and does not change;
if i reset the pic , there is another number 2742742742742742 , so goes on ...
I think i it couldn't read raw.
And the number does not change;maybe my loop is wrong

skimask · - 21st March 2008, 20:56

Try this...don't know if it'll work or not, but it should put a value on your LCD that matches the A/D result register, assuming you have something wired to PortA.0, like the wiper of a pot, with +5v on one side and ground on the other...

Code:

@ DEVICE pic16F877 
@ DEVICE pic16F877, WDT_on 
@ DEVICE pic16F877, PWRT_ON 
@ DEVICE pic16F877, PROTECT_OFF 
@ DEVICE pic16F877, HS_OSC 
DEFINE LCD_DREG PORTB 
DEFINE LCD_DBIT 0 
DEFINE LCD_RSREG PORTE 
DEFINE LCD_RSBIT 1 
DEFINE LCD_EREG PORTE 
DEFINE LCD_EBIT 0 
DEFINE LCD_RWREG PORTE 
DEFINE LCD_RWBIT 2 
DEFINE LCD_BITS 8 
DEFINE LCD_LINES 2 
DEFINE LCD_COMMANDUS 1000 
DEFINE LCD_DATAUS 225 
raw var word : trisa=1 : trisb=0 : trise=0 : adcon0 = $c1 : adcon1 = $ce
main:     adcon0.2 = 1   'start A/D conversion
wait_for_it:     if adcon0.2 = 1 then wait_for_it     'wait for A/D to finish
raw.highbyte = adresh : raw.lowbyte = adresl
lcdout $fe , 1 , DEC4 raw : goto main
END

**karamastik** · - 21st March 2008, 21:15

Originally Posted by skimask

Try this...don't know if it'll work or not, but it should put a value on your LCD that matches the A/D result register, assuming you have something wired to PortA.0, like the wiper of a pot, with +5v on one side and ground on the other...

Code:

@ DEVICE pic16F877 
@ DEVICE pic16F877, WDT_on 
@ DEVICE pic16F877, PWRT_ON 
@ DEVICE pic16F877, PROTECT_OFF 
@ DEVICE pic16F877, HS_OSC 
DEFINE LCD_DREG PORTB 
DEFINE LCD_DBIT 0 
DEFINE LCD_RSREG PORTE 
DEFINE LCD_RSBIT 1 
DEFINE LCD_EREG PORTE 
DEFINE LCD_EBIT 0 
DEFINE LCD_RWREG PORTE 
DEFINE LCD_RWBIT 2 
DEFINE LCD_BITS 8 
DEFINE LCD_LINES 2 
DEFINE LCD_COMMANDUS 1000 
DEFINE LCD_DATAUS 225 
raw var word : trisa=1 : trisb=0 : trise=0 : adcon0 = $c1 : adcon1 = $ce
main:     adcon0.2 = 1   'start A/D conversion
wait_for_it:     if adcon0.2 = 1 then wait_for_it     'wait for A/D to finish
raw.highbyte = adresh : raw.lowbyte = adresl
lcdout $fe , 1 , DEC4 raw : goto main
END

There is no activity on the screen

skimask · - 21st March 2008, 21:17

Originally Posted by karamastik

There is no activity on the screen

change lcdout $fe,1,.........
to
lcdout $fe , $80

Hook up a potentiometer connected as I described earlier and try that....

SMALL STEPS!!!!

**karamastik** · - 21st March 2008, 21:58

ADC works .

I connected the Vcc of pic to the portA.0 and it shows 1023 .
After that ; i tried

Code:

; Initialize your hardware and LCD first.

DEFINE ADC_BITS 8 ' Number of bits in ADCIN result
ADCON1.7 = 1 ' Right Justify AD result

INCLUDE "LCDbar_INC.bas" ' Include the BARgraph routines

Value VAR WORD ' Must be a WORD even though AD is 8bit

LCDOUT $FE, 1 ' Clear Screen

Loop1:
ADCIN 0, Value
LCDOUT $FE,2,"Value = ",DEC Value," "
; syntax- BARgraph Value, Row, Col, Width, Range, Style
@ BARgraph _Value, 2, 0, 16, 255, lines
GOTO Loop1

The bars are ok , don't flickr
but the word "value" always flickering , why ?
And whene there is no input to the portA.0 , the value becomes 276 and there are still full bars ? (I know there are too many questions

, but i want to learn )

It seems , the problem is my circuit output

By the way , as i said before , whene there is 5V , i don't want any bars , there must be full bars at 3.9V
How can i change this code to run like for my project or there must be a different code ?

Code:

Loop1:
    ADCIN  0, ham
    LCDOUT $FE,2,"Value = ",DEC ham,"   "
    ; syntax- BARgraph   Value, Row, Col, Width, Range, Style
    @         BARgraph  _ham,   2,   0,    16,   255,  lines
    
Goto Loop1

Thank you very much again.

skimask · - 21st March 2008, 22:30

but the word "value" always flickering , why ?

Probably because something is overwriting it or clearing the screen, then you re-print the VALUE on the LCD...

as i said before , whene there is 5V , i don't want any bars , there must be full bars at 3.9V

Simple math
Minimum = 5V (1023 ADC counts)
Maximum = 3.9V (798 ADC counts)
Spread = 1.1V (225 counts)
raw = 1024 - raw 'flips the value upside-down
raw = raw / 14 '14 counts per box, assuming 16 boxes
Surely you can do something with that...

**karamastik** · - 21st March 2008, 22:38

Okey my friend , thank you for your patience and for your helps

Today is enough for me ;
i'm working about this project from 9 o'clock to now.
I think , it's time to make my brain free.
And one last question ; i don't know that you are interested in integrated circuits; if you are ; i want to ask something.
I have 2 op-amps LM358 and i learned that , the maximum supply current for LM358 is 600mA . I have a power supply with 6-9-12-15 adjustable ; and it says , it can give a current of 2.5A
So, if i connect it to my op-amps , do they blow out ?
Thank you .

**karamastik** · - 21st March 2008, 20:56

By the way , i applied the codes from the " LCD BARgraphs" subject:

; Initialize your hardware and LCD first.

DEFINE ADC_BITS 8 ' Number of bits in ADCIN result
ADCON1.7 = 1 ' Right Justify AD result

INCLUDE "LCDbar_INC.bas" ' Include the BARgraph routines

Value VAR WORD ' Must be a WORD even though AD is 8bit

LCDOUT $FE, 1 ' Clear Screen

Loop1:
ADCIN 0, Value
LCDOUT $FE,2,"Value = ",DEC Value," "
; syntax- BARgraph Value, Row, Col, Width, Range, Style
@ BARgraph _Value, 2, 0, 16, 255, lines
GOTO Loop1

It works but the lines change very fast and i can't recognize also the 'value' word changes ?
In fact , i don't need value, i just need line bars.

skimask · - 21st March 2008, 20:58

Originally Posted by karamastik

By the way , i applied the codes from the " LCD BARgraphs" subject: ?
In fact , i don't need value, i just need line bars.

If you can't get the value of your A/D to change....how do you expect to see changing bars?

Small steps....

I'm done....

**karamastik** · - 21st March 2008, 21:13

Yes , you are wright ;it should read the analog value.
I have cell phone detector , and whene there is no cell phone activity ; i have 5V at the output.When there is a phone activity , my circuit detects the electromagnetic wave thus the current increases at the output .
As the current increases , the voltage drops from 5V to approximately 3.8V .
I must see no bars at 5V , and must see full bars at appr. 3.8V .
I wish i'm understood.

Thank you for your helps.
Can you explain , why the bars are appearing very fast ?
I can't see them.They are like a ghost.
I'm using 20MHz pic , does it differ ?
I think it mustn't .
I won't stop, will try.If i stop, my school stops me

Thanks again

Thread: Help for my project(16f877,2x16LCD,)

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