Thread: ADC doesnt work

Code:

void ky_dReadSteering(void){
	uchar temp; 


	d_kyStrADReg = u_adcPort(AN0);
	d_kyStrADReg = d_kyStrADReg >>6;


	if(d_kyStrADReg < 0x74)
    {
    	d_kyStrAD = 0x00;				/* K_OFF        */
	}
	else if(d_kyStrADReg < 0x4D8)
	{
		d_kyStrAD = 0x9d;				/* MUTE			*/
	}
	else if(d_kyStrADReg < 0x745)
    {
    	d_kyStrAD = 0xcd;				/* VOL UP       */
    }
	else if(d_kyStrADReg < 0x278)
	{
    	d_kyStrAD = 0x0d;				/* VOL DN       */
	}
	else if(d_kyStrADReg < 0xC5C)          
    {
    	d_kyStrAD = 0x21;				/* FUNC			*/
	}
	else if(d_kyStrADReg < 0x9EF)          
    {
    	d_kyStrAD = 0x8a;				/* SEEK UP      */
	}
    else if(d_kyStrADReg < 0xE4C)
    {
    	d_kyStrAD = 0x44;				/* SEEK DN      */
	}
    else 
    {
        d_kyStrAD = B00000000;				/* K_OFF        */
	}


	if( d_kyStrAD != (uchar)d_kyStrPort.all )
	{
		d_kyStrPort.all = d_kyStrAD;
		d_stPortCnt = 0;
		f_stPortchg = 1;
	}
	else
	{
(KY_STR_SCAN_COUNT-1) */
		if(f_stPortchg)
		{
			if(d_stPortCnt > (KY_STR_SCAN_COUNT - 1))
			{
				f_stPortchg = 0;
				d_stPortCnt = 0;
				f_scnrq = 1;				/*1:key scan request		*/
			}
			else
				d_stPortCnt++;
		}
	}
}

this code is for an AD converter. my voltages are
vol dn 2.39
vol up 1.704
seek dn 1.08
seek up 3.29
func 0.19
mute 0v

my pull up v is 3.3 with 1000 ohm pull up resistor

please tell me what i've done wrong!

Thank you

hi laserlight,

the d_kystrAD is the value of the remote key for each functions (func, mute, vol up vol dn etc) obtained from the remote via AD
the d_kyStrADReg is the value of the converted AD from the AD converter

while the v drop is consistent and it should be working, it doesnt. the port is declared correctly and the compiler has a built in ADC.
im thinking its the values of the d_kyStrADReg but im not sure how am i to change the values, i meant into what value.

does this ans your Q?

Originally Posted by stahta01

Where and why do you have a "1000 ohm pull up resistor"?

What chip are you using?
What Compiler are you using?
Do you have Analog input enabled?
What is wrong?
(What is the output that is wrong? What should it be instead?)

Tim S.

1kohm is put at the ADC input (before the V goes into the ADC).
and yes my analog input is enabled.
im using a TMPM321F10FG chip
Im using a keil microvision 4

seems that only 2 of my buttons are functioning. the last 2 ones. for the top 4 buttons, it doesnt seem to go into the range at all. even when I have set the watch on the kyStrADReg. the values stated on the watch is similar or in the range of the keys but they do not go in. im baffled. do u know why?

Without seeing a schematic and how you actually configure your microprocessor (Post the complete program!) it's almost impossible to tell you what is wrong. Also post a link to your microprocessor/development board data sheet.

Jim

Originally Posted by jimblumberg

Without seeing a schematic and how you actually configure your microprocessor (Post the complete program!) it's almost impossible to tell you what is wrong. Also post a link to your microprocessor/development board data sheet.

Jim

hiya jim, thanks. but i've solved most part of it. seems that i dont need to shift it at all. and that is what the main cause for the remote not to work.I'm only left with one more and it should be done.

Just one question (not cprog related though) i have 6 buttons and all 5 of them have different voltage drops across them except for one (which doesnt have any drop or very very little voltage drop across the switch. and therefore I cant seem to get any reading.

Now my circuits a little rusty, but i know that with a resistor of 162 ohm and 3.3 v pull up and 1000 ohm pull up resistor, i should be getting much much lesser than that.

Thats the only button that I am having problems with.