Problem with ADC1763 ADC

lpcware — Wed, 15 Jun 2016 18:05:09 GMT

Content originally posted in LPCWare by alexxx on Tue Jun 25 23:31:01 MST 2013

Hi!

I read ADC every 10ms, inside systick interrupt. It is ADC 0. The problem is that every now and then (something like once or twice in a minute), the ADC returns 0xFFF. I investigated with the oscilloscope, but there is nothing wrong with hardware line on ADC0. Has anyone experienced a similar problem? I am using LPC1763, IAR compiler. My code is:

void initialize_adc (void)

{

ADC_Init(LPC_ADC, 100000); //100KHz

ADC_IntConfig(LPC_ADC,ADC_ADINTEN0,DISABLE);

ADC_ChannelCmd(LPC_ADC,ADC_CHANNEL_0,ENABLE);

}

unsigned int return_adc_channel ( const unsigned char CHANNEL_SETUP ) //CHANNEL_SETUP is always 0 for this project

{

_UINT temp;<span class="Apple-tab-span" style="white-space: pre;"> </span>//this is a union

// Start conversion

ADC_StartCmd(LPC_ADC,ADC_START_NOW);

//Wait conversion complete

while (!(ADC_ChannelGetStatus(LPC_ADC,CHANNEL_SETUP,ADC_DATA_DONE)));

//get ADC data

temp.ivalue = ADC_ChannelGetData(LPC_ADC,CHANNEL_SETUP);

return temp.ivalue;

}

So the problem is that this temp.ivalue returns a 0xFFF, but the voltage on ADC0 doesn't change. After this faulty measurement in the next ADC conversion, the returned value is again OK.

topic Problem with ADC1763 ADC in LPC Microcontrollers

Problem with ADC1763 ADC