CC2540 GPIO state under low power mode

daniel su

Other Parts Discussed in Thread: CC2540

hello sir;

I am running a CC2540 based board with two LEDs connected to P0.1 and P0.0 Also a buzzer is driven from PIO1.6. I try to run the keyfobdemo under BLE SDK1.2 and turn on both LEDs and start advertisement from system start . It seems that the LEDs will flash. then after the advertimement timeout , the LEDs continue flash,but slower.

If the power saving is turned off for whole system , the LEDs state will be OK(keep on). i find flowing infrmation form CC2540 guide.

"In power modes PM1, PM2, and PM3, the I/O pins retain the I/O mode and output value (if applicable) that was set when PM1/PM2/PM3 was entered"

so the low power mode will influence the GPIO state or power?

over 13 years ago

0 Igor Sherer over 13 years ago

Guru 31280 points

daniel su said:
so the low power mode will influence the GPIO state or power?

Entering to lower power modes, such as PM2/PM3 shouldn't have an impact on the state of pin/s,

however, if a pin configured as peripheral then the state of that pin can be affected, since most

of peripherals are not functional during PM2/PM3

0 Aslak N. over 13 years ago

TI__Mastermind 23440 points

Hi Daniel,

The Keyfobdemo project uses some HAL drivers for LEDs. You will note that in a function called HalLedEnterSleep under HAL/Target/CC2540EB/Drivers/hal_led.c in the IAR project, the LEDs are turned off during sleep. This is because they draw a high amount of current (~15-20mA maybe), so the battery will be drained very quickly.

Best regards,
Aslak

0 daniel su over 13 years ago in reply to Aslak N.

Intellectual 505 points

Hi Aslak,

you are right. I find the problem . HalLedEnterSleep called from HalSleep causes this. Thanks a lot.

Best regards,

Daniel

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CC2540 GPIO state under low power mode