Re; Comparator in CC2541

Jayaraj KT

Other Parts Discussed in Thread: CC2541

Hi everyone

Greetings of the day

I want to use Analog Comparator which is connected to port 0_4 and port0_5 in CC2541 to measure the voltage change across the battery so.

My question is How to enable that comparator I am not getting how to make that but in the user guide they have stated as we need to set the analog pins but how to do that please anyone explain me??

Thanks in advance

With regards

Jayaraj

over 10 years ago

0 Fredrik K over 10 years ago

TI__Guru** 106705 points

Hi Jayaraj,

This is explained in the CC253x/4x User Guide chapter for comparator and IO control. You will find this document at the top of the product page. If you download the CC254x Peripheral SW examples in the software section on the product page you can use the ADC example as a reference.

Cheers,
Fredrik

0 Jayaraj KT over 10 years ago in reply to Fredrik K

Intellectual 385 points

Hi Fredrik

Yes thanks for the information but my question is how to convert P0_4 and P0_5 only as analog pins remaining should be as digital pins.

for general purpose I/O is below code is fine?
P0SEL &= (~BV(4)); //Set P0.4 to GPIO functionality
P0DIR |= BV(4); //Set P0.4 to GPO
P0_4 = 0; //This will set to Low
P0_4 = 1; //This will set to High

If yes then how to make this pin as Analog I/O thats my question?

With thanks and regards

Jayaraj

0 YiKai Chen over 10 years ago in reply to Jayaraj KT

Guru 735685 points

If you intend to set P0.4 and P0.5 as analog input (I suppose this means ADC input) and other as digital pins (I suppose this means GPIO), you should use the following code.
P0SEL = 0x0; //Reset All P0 pins to GPIO
P0SEL |= (BV(4)|BV(5)); //Set pin4 and 5 of P0 as ADC input.

0 Fredrik K over 10 years ago in reply to Jayaraj KT

TI__Guru** 106705 points

To enable analog IOs you must write to the APCFG register. This is explained in the user guide, chapter 7.6.7.

0 Jayaraj KT over 10 years ago in reply to Fredrik K

Intellectual 385 points

Hi Fredrik

But I need only P0_4 and P0_5 as analog input remaining should be as the digital input so, how to make that?

with thanks and regards

Jayaraj

0 YiKai Chen over 10 years ago in reply to Jayaraj KT

Guru 735685 points

Add the following line to my previous code.
APCFG |= (BV(4)|BV(5));

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Re; Comparator in CC2541