Stable ADC readings

[mister_e]

3902 is actually 39K, so the other resistor are also bad... ok then. So be it.

modify what's in red

'
'       Software Variable
'       =================
        ADRes       VAR WORD    ' ADC Reading
        BTN         var byte    ' Data to be sent to PORTB
        i           VAR BYTE    '
        ADCChannel  VAR BIT     '
        ADCButton   VAR WORD [3]'
'
'       Software constant
'       =================
        ADCSafety   CON 10              ' min/max range for ADC Reading
                                        '
        ADCNone     CON 814 - ADCSafety ' 
        ADCButton[0]  = 90              ' button 1 or 4 
        ADCButton[1]  = 164             ' button 2 or 5 
        ADCButton[2]  = 270             ' button 3 or 6

should work

This is Why I asked to measure with your ohmmeter a couple of post back... and nope I'm not going to decipher a PCB

You have everything on hand....

[mister_e]

I don't understand : TRISB = ((DCD i) << (ADCChannel*3)) ^255

Check your manual about DCD, logical and bitwise operators. It's all there

Anyone wants to explain it?

Yes I've put some black magic in

[mazoul72]

Hello Steve ,

i have some erratic values on BTN result ( BTN = TRISB ) under pic smulator ide 6.91 .
like 1 . 2 . 4 .255 and cycle infinite .

But i will try this evening on led test or resistors.

I note in 16f877x datasheet that with "1" TRISB , we have High Impedance so we can choose whose resistor to be put off .
But with other state bit of TRISB , i don't understand how tie to common +5V of car radio (TIP) to the RB0,RB1,RBx..... ???
We have agree that it is a result of a resistor between common ground (sleeve) and +5V (tip) on jack "grip" .

Hervé.

[mister_e]

Never trust a sim... as simple as that. They're on the market for laziness and to make good money out of it. Good enough to replace any xBox, Nintendo... or some porn.

You tie the resistor like the guy in that previous thread. One side on the PIC the other side are tied together and sent to the Radio.

[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 .