revolution counter

[lerameur]

I got the circuit working now without the ADC, thats the one I will use.
BUT,I also tried the ADC, it only works in 10 bit mode when I try the 8 bit mode, nothing appears on the LCD. Here the progrm, but before here is the two lines I changed for the 8 bit mode:

ADCON1 = %10000010
Define ADC_BITS 8 ' Set number of bits in result

why is this happening?

INCLUDE "modedefs.bas" 'Includes supoprt for PicBasic language
@ DEVICE pic16F88, INTRC_OSC, CCPMX_ON
OSCCON=$60 ' use internal 4MHZ osc

ANSEL = 0
CMCON = 7 ' Turn OFF the comparators so pins can be used as digital I/O-pins
ADCON1 = %00000010 ' Analog to digital configuration register (ADCON)
' Set PORTA to digital

' Define ADCIN parameters
Define ADC_BITS 10 ' Set number of bits in result
Define ADC_CLOCK 3 ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50 ' Set sampling time in uS

ADCON1 = %10000010 ' Analog to digital configuration register (ADCON)
' Set PORTA to digital

'/////////////////////////
'// LCD configuration //
'/////////////////////////

DEFINE LCD_DREG PORTB ' Set LCD Data port
DEFINE LCD_DBIT 4 ' Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_RSREG PORTB ' Set LCD Register Select port
DEFINE LCD_RSBIT 1 ' Set LCD Register Select bit
DEFINE LCD_EREG PORTB ' Set LCD Enable port
DEFINE LCD_EBIT 0 ' Set LCD Enable bit
DEFINE LCD_BITS 4 ' Set LCD bus size (4 or 8 bits) '4 therefore put wire at 4, 5, 6 and 7 of LCD
DEFINE LCD_LINES 2 ' Set number of lines on LCD
DEFINE LCD_COMMANDUS 2500
DEFINE LCD_DATAUS 250
DEFINE CHAR_PACING 2000
pause 1000


'/////////////////////////
'// PIN configuration //
'/////////////////////////

TRISA = %11100111 ' Set PORTA to all input
TRISB = %00001100 ' Set PORTB to all output
PortA = 0

'///////////////////////////////////////////////
'// Variable Declaration and initialization //
'///////////////////////////////////////////////
Output_Pot var byte
OldOutput_Pot var byte
Revolution var word
counter var byte

revolution = 0
Output_Pot = 0
OldOutput_Pot = 0
counter = 0

'Get initial value
'ADCON0.2 = 1 'Start Conversion
ADCIN 1, OldOutput_Pot 'analog pin 1 (RA1) get the 8 bit result
pause 50
if OldOutput_Pot > 512 then
OldOutput_Pot =1
else
OldOutput_Pot =0
endif

Mainloop:

'ADCON0.2 = 1 'Start Conversion
ADCIN 1, Output_Pot 'analog pin 1 (RA1) get the 8 bit result
pause 50

'Calculate the distance
if Output_Pot > 512 then
Output_Pot =1
else
Output_Pot =0
endif

if OldOutput_Pot == Output_Pot then
goto Mainloop
endif
if OldOutput_Pot != Output_Pot then
counter = counter +1 'If oldOutput_pot is different then Output_pot
OldOutput_Pot = Output_Pot
if counter =4 then
Revolution = Revolution + 1
counter =0
endif
endif

lcdout $FE,1, "Counter:",dec counter
lcdout $FE,$C0, "Revolution:",dec Revolution
pause 150


GOTO Mainloop
end

[skimask]

BUT,I also tried the ADC, it only works in 10 bit mode when I try the 8 bit mode, nothing appears on the LCD. Here the progrm, but before here is the two lines I changed for the 8 bit mode:

Did you set it for left justify or right justify? Makes a difference...

[lerameur]

it is in the code above:

with this it works:
ADCON1 = %00000010
Define ADC_BITS 10 ' Set number of bits in result


but not:

ADCON1 = %10000010
Define ADC_BITS 8 ' Set number of bits in result

[skimask]

Right, with one you're putting the 10 bit value (justified left) into a byte, with the other, you're putting the 10 bit value (justified right) into a byte, trying to stuff 10 bits into a spot for 8 bits.
So, with one, you get the lower 8 bits of the 10 bits, with the other you get the upper 8 bits of the 10 bits.
Which one is it? That's for you to figure out....(hint: if you use a word variable for reading, you'll figure it out quickly if you also use the LCD to display that value)

[lerameur]

I am using the same config as the sample program on melabs:
http://www.melabs.com/resources/samples/pbp/adcin8.bas

as you can see mine is not working.

k

[skimask]

I am using the same config as the sample program on melabs:
http://www.melabs.com/resources/samples/pbp/adcin8.bas
as you can see mine is not working.
k

Except that they're using 8 bits and a byte, and you tried using 10 bits and a byte.
(hint: see the hint above about the hint in post #25)

[lerameur]

oups, ok i was sleepy last night,


thanks for your help

ken