sleep_mode_enter

[Kafka]

Hello everyone. I have a question about sleep_mode_enter() behavior. I'm using nRF5_SDK_12.3.0 and nRF51822 for my project.

I put a lot of printf statements in the example project "ble_app_uart" to see how this program actually works. Then, I noticed that functions before sleep_mode_enter never get called or stopped in middle of execution.

for example, in on_adv_evt function

I put a printf statement

case BLE_ADV_EVT_IDLE:

printf("BLE_ADV_EVT_IDLE\r\n"); //Here

sleep_mode_enter();

break;

My terminal only shows "B" not "BLE_ADV_EVT_IDLE". if you have more statements between the above printf statement and sleep_mode_enter, these functions were never called.

Can anyone tell me why this happens? Thank you.

[Joakim Jakobsen]

Hi Kafka!

The reason that you only get one single "B" in your terminal output is probably cause the device will enter sleep before the full message has been transmitted.

To avoid this, you can set up a flag and wait for the BLE_EVT_TX_COMPLETE event to be returned, before going to sleep.

Best regards,
Joakim.

[Kafka]

Thank you for your quick response.

I will try to add the state and see what happens this weekend.

Sincerely,

Kafka

[Joakim Jakobsen]

No problem. Let me know how it works out.

[Kafka]

Joakim. I could not solve my issue with BLE_EVT_TX_COMPLETE. But, I could solve this problem. what I did was creating a new variable int Am_I_Sleepy as global variable, and move printf statement and sleep_mode_enter into main(). My device prints and goes to sleep when Am_I_Sleepy is set. I guess the issue was coming from interrupt in on_adv_evt.

[Joakim Jakobsen]

I'm glad you were able to solve your problem.
Be sure to let us know if you have any more questions.