I was using an ADC channel ADC0.1 in lpC2468 for taking controller to power down, and it worked properly. Now I configured ADC channel 2 ADC0.2 for reading value from thermistor, as I load code into the controller the controller goes to power down just after reset after code loading.
if i comment init_adc_thermistor() i.e. ADC channel 2 initialization the system works properly,controller does not go to power down.
I am using both channels turn by turn, as shown in code in interrupt routine of channel1, i configure channel 2 and in interrupt routine of channel 2 i configure channel 1 of ADC
My code has following format
Void main() { Init_peripherals(); Init_Adc(); While(1){ //statements } } ADC channel 1 initailized for power down void Init_Adc(void){ PINSEL1 |=0x00004000; AD0CR = 0X0021ff01; VICVectAddr18 = (unsigned)ADC_on_con_isr VICIntEnable |= 0x00040000; AD0INTEN = 0X00000001; AD0CR |= 0X01000000; } channel1 interupt routine void ADC_on_con_isr(void) __irq{ int Dvalue; Dvalue =(AD0DR0 >> 6)& 0x3ff; AD0DR0 = 0X00000000; //CLEAR ALL DATA AD0GDR=0X00000000; VICVectAddr = 0x00000000; init_adc_thermistor();ADC channel 2 initialized if(Dvalue<0x292){ //power down } } ADC channel 2 initailized for thermistor void init_adc_thermistor(void){ PINSEL1 |=0x00010000; AD0CR = 0X00218002; VICVectAddr18 = (unsigned) VICIntEnable |= 0x00040000 AD0INTEN = 0X00000002; AD0CR |= 0X01000000; } channel2 interupt routine void ADC_on_thermistor(void)__irq { int Dvalue1; Dvalue1 =(AD0DR1 >> 6)& 0x3ff; AD0DR1 = 0X00000000; AD0GDR=0X00000000; VICVectAddr = 0; Init_Adc(); ADC channel 1 initialized If(Dvalue1<0x170) //printer off }
Now, I'm confused - why do you initialize the ADC again and again?
Use a single ISR.
Start a conversion.
Let the ISR pick up the data - either from that specific channel. Or after all enabled channels has been converted.
Your ISR should not play around like it does now.
@Per Westermark sir u mean to say that i should do like this
void Init_Adc(void){ PINSEL1 |=0x00014000; adc function selected for both pins AD0CR = 0X00218003; both channels selected VICVectAddr18 = (unsigned)ADC_on_con_isr VICIntEnable |= 0x00040000; AD0INTEN = 0X00000003;interrupts enabled for both channels AD0CR |= 0X01000000; } void ADC_on_con_isr(void) __irq{ int Dvalue,adc_value; channel 1 data reading Dvalue =(AD0DR0 >> 6)& 0x3ff; AD0DR0 = 0X00000000; //CLEAR ALL DATA AD0GDR=0X00000000; channel 2 data reading adc_value =(AD0DR1 >> 6)& 0x3ff; AD0DR1 = 0X00000000; AD0GDR=0X00000000; VICVectAddr = 0x00000000; if(Dvalue<0x292) //power down if(adc_value<0x170) //printer off }
I haven't scanned through all your bits there, but consider checking bit DONE in the ADxDRx register to verify if the interrupt handler has a new valid value available - this flag is auto-cleared when you read from the data register so you don't need to write zero to the register.
And either run conversion continuously (which requires that you slow down the ADC conversion speed) or have your main loop now and then start a conversion.