hi all,

i'm new in the group , but i hope i will be helpful with you & share
my little knowledge with you.

well, i'm working on the OLIMEX LPC2138 evaluation board & ARM cross
works compiler & debugger.
i'm working on implementing a Voice Over Wifi phone.

i want to run the ADC & get samples for the voice @8khz ,& i will put
the samples in a frames to pass it for the compression code.

i have written a code for the ADC_0_ISR interrupt handler, but when i
debug the code it never enters the ADC_0_ISR , to be known i
configured the ADC0 to work at 88khz & in burst mode.

i choosed 88khz ,because it is said in the LPC2138 manual that each
conversion takes 11 clks to get 10 bits. am i doing write ?

at last here is the code that i tested :)
//////////////////////////////
#include "LPC213x.h"
#include <__armlib.h>

void init_ADC(void)
{
PINSEL0 |= 0x00000300; // select pin0.4 as AD pin AD0.6
PCONP |= 0x00001000; // enable the power to ADC.0
AD0CR = 0x00214040; // configure the AD & run at 88Khz clk at
//CLK_DIV = 40, @cclk = 14.475Mhz
}

int ADC_Data(void) // i'm only scaning on channel 6 where the
// microphone is connected
{
int data_sample ;
int channel ; // we work on channel 6 , AD0.6
int value;
value = AD0DR;
channel = ((value >> 24 ) & 0x00000007);
if (channel == 6)
{
data_sample = ((value >> 6 ) & 0x000003ff);
return data_sample ;
}
}

static void ADC_0_ISR(void) __attribute__ ((interrupt ("IRQ")));

int B1samples[160]={0}; // buffer1 for the sampled voice
int B2samples[160]={0}; // buffer2 for the sampled voice
int samplesCount; // samples count for the sampled voice
static void ADC_0_ISR(void)
{

if (samplesCount <160 )
{
B1samples[samplesCount] = ADC_Data();
samplesCount++;
}
else if (160<=samplesCount <320 )
{
B2samples[samplesCount] = ADC_Data();
samplesCount++;
}
else
{ samplesCount = 0 ;
B1samples[samplesCount] = ADC_data();
}
__ARMLIB_isrDisableIRQ();

VICVectAddr = 0; // Update VIC priorities
}

int main (void)
{
PINSEL0 |= 0x00000300; // select pin0.4 as AD pin AD0.6
int i,j;
int sampleddata[160]={0};

VICIntSelect &= ~0x4000; // AD0 interrupt is an IRQ interrupt
VICIntEnable = 0x4000; // Enable AD0 interrupt
VICVectCntl0 = 0x32; // Use slot 0 for AD0 interrupt
VICVectAddr0 = (unsigned int)ADC_0_ISR; // Set the address of ISR
// for slot 0

__ARMLIB_enableIRQ(); // Enable Interrupts
__ARMLIB_isrEnableIRQ(); // enable the interrupts

init_ADC();

while(1)
{
if (samplesCount =9)
for (i=0;i<160;i++)
sampleddata[i] = B1samples[i]; // we will pass the
//B1samples to encoder
if (samplesCount =9)
for (j=0;j<160;j++)
sampleddata[j] = B2samples[j]; // we will pass the
//B2samples to encoder
}
}
///////////////////////

i really appreciate your help to spot the error & tell me what i have
done wrong.

thanks all,

osama el haggar Start a New Thread

--- In l..., "osaelhaggar" wrote:
Hi!
Are u sure u are starting your A/D conversion.
AD0CR = 0x00214040
it doesnt seem so.
U can start it by placing D0CR|=0x01000000 in your code.
I would suggest check AD0GR register if u are doing only conversion on
one channel.

int ADC_Data(void) // i'm only scaning on channel 6 where the
// microphone is connected
{
int data_sample ;
int channel ; // we work on channel 6 , AD0.6
int value;
value = AD0DR;
channel = ((value >> 24 ) & 0x00000007);
if (channel == 6)
{
data_sample = ((value >> 6 ) & 0x000003ff);
return data_sample ;

This is how i do it when im measuring on one channel only

void FIQ_Handler(void)__fiq
{
unsigned int result;
result0GDR;
result=((result>>6)& 0x03FF);

Regards!! Start a New Thread

--- In l..., "osaelhaggar" wrote:
Hi
VICIntSelect &= ~0x4000; // AD0 interrupt is an IRQ interrupt
VICIntEnable = 0x4000; // Enable AD0 interrupt

Should be 0x00040000

Regards Start a New Thread