Stable ADC readings

[mazoul72]

Hi Steeve,

i test intensity value with some résistors tie together to one led.

But with your program , trisb stay at 255 , i put some select case for test but no trisbx.0 work (255 always)
I will try to my test platine .
I understand your "voodoo formule" , it is for have only one button put on , no action with 2,3 .. together .

Regards.
Hervé

[mazoul72]

i repeat my question :
how tie the resistors on the side of PIC together to have a resultant resistor in parallele ?
i agree that the other side is tie together to the radio , but on the ground ,yes
but the +5V for PIC RBx ?

Regards.

Hervé

[mazoul72]

in fact , the simulator isn't reactif with adc , i must go slowly with an0/an1 choice .
But step by step around button(i) , it works.

I must add six other buttons in programm and .

[mazoul72]

Can i use btn as word variable for a select case like 1110111111111111 ?
(with your formule dcd(i).... )
i can't for the moment ...
i use adcchannel 0 to 3 .

Regards.
Hervé

[mister_e]

pbp 3 manual section 2.12

[mazoul72]

Hello,

it works all !
great and many thanks.

I made another "formule" in addition to yours (to work with 12 buttons and 4 channels__3 buttons on a wire)
It is perhaps not proper .
I add to this : PIC Simulator IDE 6.91 works great , all test with it and great.


. btn = ((DCD i) << (ADCChannel*3))^255
. if ADcchannel = 3 and btn = %11111111 then btn = (btn - (3*adcchannel)) << i
. gosub choose
..
..
ADCChannel = ADCChannel + 1 'Switch to the other ADC channel
if ADCchannel = 4 then adcchannel = 0
..
..
choose:
select case btn
' first bloc of 6 buttons
case %11111011 ' AN0-270 --- 47k and 5k = 4.6k
TRISB.0 = 0 ' 5k and 5k = 2.5k
TRISB.1 = 0
case %11111101 ' AN0-164 --- 47k and 10k = 8.2k
TRISB.1 = 0 ' 5k and 5k = 2.5k
TRISB.2 = 0 ' 47k and 47k = 22k
case %11111110 ' AN0-90 --- 47k and 22k = 15k
........


Regards
Hervé

[mazoul72]

i am so disapointed because it doesn't work on test real card and works on simu.
strange...
i have microcode studio with 15 days trial .(compiler 3.0.0.1)

TRISA = %00001111 ' RA0 et RA1 en entrée

TRISB = 255 ' Disconnect all resistor from the circuit (Haute impédance)

PORTB = 0 '

'

' ADC

' ---

DEFINE ADC_BITS 10 ' Set number of bits in result

DEFINE ADC_CLOCK 3 ' Set clock source (rc = 3)

DEFINE ADC_SAMPLEUS 50 ' Set sampling time in

ADCON1 = %10000010 ' RA0 à RA3 and RIGHT JUSTIFIED



'

' Software Variable

' =================

ADCRes VAR WORD ' ADC Reading

btn var byte ' Data to be scan

i VAR BYTE '

j var bit

ADCChannel VAR byte '

ADCButton VAR word [3]'

'

' Software constant

' =================

j = 0

ADCSafety CON 10 ' min/max range for ADC Reading

'

ADCNone CON 814 - ADCSafety '

ADCButton[0] = 90 ' button 1,7 or 4,10

ADCButton[1] = 164 ' button 2,8 or 5,11

ADCButton[2] = 270 ' button 3,9 or 6,12



Start:

TRISB = 255

ADCIN ADCChannel,ADCRes ' Read ADC

'

if (ADCRes < ADCNone) Then ' Any button down?!?

' - Yes!

FOR i = 2 TO 0 STEP -1 ' Loop through all 3 calculated posibilities

' Test against calculated ADCresult

' and allow a range of +/- ADCSafety

IF (ADCRes > (ADCButton[i]-ADCSafety)) AND (ADCRes < (ADCButton[i]+ADCSafety)) THEN

' Valid ADC result, clear the coresponding I/O

btn = ((DCD i) << (ADCChannel*3)) ^255

if (ADcchannel = 3 and btn = 255) then btn = ((btn - (3*adcchannel)) << i)

gosub choix

pause 200

i=0 ' and getOut of here

ENDIF '

NEXT '

else ' - NO!

ADCChannel = ADCChannel + 1 'Switch to the other ADC channel

if ADCchannel = 4 then adcchannel = 0

ENDIF

GOTO Start

choix:

select case btn

' premier bloc de 6 boutons
case %11111011 ' AN0-270 --- 47k and 5k = 4.6k

TRISB.0 = 0 ' 5k and 5k = 2.5k

TRISB.1 = 0

case %11111101 ' AN0-164 --- 47k and 10k = 8.2k

TRISB.1 = 0 ' 5k and 5k = 2.5k

TRISB.2 = 0 ' 47k and 47k = 22k

case %11111110 ' AN0-90 --- 47k and 22k = 15k

TRISB.2 = 0

TRISB.3 = 0 ' 10k and 10k = 5k

case %11011111 ' AN1-270 --- 47k and 2.2k = 2.1k

TRISB.3 = 0 ' 47k and 15k = 11.3k

case %11101111 ' AN1-164 --- 100k and 22k = 18k

TRISB.4 = 0 '

TRISB.0 = 0 '

case %11110111 ' AN1-90

TRISB.5 = 0

TRISB.1 = 0

TRISB.3 = 0

' deuxième bloc de boutons

case %11111111 ' AN2-270 --- 47k and 5k = 4.6k

TRISB.7 = 0 ' 5k and 5k = 2.5k

TRISB.6 = 0

case %01111111 ' AN2-164 --- 47k and 10k = 8.2k

TRISB.5 = 0 ' 5k and 5k = 2.5k

TRISB.4 = 0 ' 47k and 47k = 22k

case %10111111 ' AN2-90 --- 47k and 22k = 15k

TRISB.2 = 0

TRISB.3 = 0 ' 10k and 10k = 5k

case %11011000 ' AN3-270 --- 47k and 2.2k = 2.1k

TRISB.7 = 0 ' 47k and 15k = 11.3k

case %11101100 ' AN3-164 --- 100k and 22k = 18k

TRISB.5 = 0 '

TRISB.0 = 0 '

case %11110110 ' AN3-90

TRISB.5 = 0

TRISB.7 = 0

TRISB.3 = 0

end select

return