cc2540 adc

Mallikarjuna Gante

Prodigy 90 points

Other Parts Discussed in Thread: CC2540

Hi everyone,

am new to IAR compiler and cc2540.

i completed usart communication..now am trying to interface ANALOG sensor using ADC pin

of cc2540 but am not getting proper output..:(

here am attaching my code pls check and let me know my mistakes..

PROGRAM:

void adc()
{

unsigned int adc_result;
CLKCONCMD = (CLKCONCMD & (0x40 | (0x07)));
while (CLKCONSTA & 0x40 ); // Wait until clock source has changed

ADCCON1 = 0x00;
ADCCON2 = 0x00;
P0SEL &= ~0x10; /* Set pin (sample) as GPIO */
P0DIR &= ~0x10; /* Set pin as input*/
P0INP |= 0x10;
APCFG |= 0x10; /* configure ADC on pin4*/

ADCCON1 |= 0x30;

ADCCON2 |= 0xb4;

//ST=1;
ADCCON1 |= 0x40;

tv = ADCL;
tv |= (((unsigned short) ADCH) << 8);
tv >>= 4 ;
lv = tv;
}

over 11 years ago

0 Greenja over 11 years ago

Guru 22270 points

Hello M,

The simplest solution would be to use the HAL ADC API. Look at the battery service for how to measure he voltage on the ADC port pin.

You can also download the swrc257.zip and look at the ADC sample code. http://www.ti.com/lit/zip/swrc257

All this information is also found in the CC254x User Guide swru191 section 12. http://www.ti.com/lit/swru191

Thanks,

0 Mallikarjuna Gante over 11 years ago in reply to Greenja

Prodigy 90 points

Dear greenja

Thank u for the replay..

i will follow ur instruction and i have one more question..

is it possible to measure less than 1v voltage on the ADC port pin..

Thank u once again..

0 Greenja over 11 years ago in reply to Mallikarjuna Gante

Guru 22270 points

Hello M,

It is possible to measure from 0 to 3.3V using the ADC. If you are only measuring voltages below 1V, the accuracy of the results may not good enough for you application. You may want to scale your 0-1V to 0-3.3V. There are examples of resistor circuit and OP Amp circuits on the web to do this.

Thanks,

0 Mallikarjuna Gante over 11 years ago in reply to Greenja

Prodigy 90 points

hii greenja,

ur rite below 1v the out put is not accurate..now my adc application is working properly..

thank u for the help....:-)

Thank U......

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