Not able to wake the board from deep sleep(System off)

RE: Not able to wake the board from deep sleep(System off)

davidm — Thu, 17 Oct 2019 04:01:45 GMT

Hi Simon

I just wanted to update you that I am still trying to get this to work, I will let you know the results either way.

Thank you.

RE: Not able to wake the board from deep sleep(System off)

Simonr — Thu, 10 Oct 2019 10:48:56 GMT

Hi David

You're correct, calling the disconnect in the CONNECTED event might not be the best idea. Sorry about that.

In order to check when an event has been received, I think the easiest way would be to create a service on the peripheral side that can be discovered and read by the central. We have a guide on creating your own custom BLE services here, which is great for learning purposes as well. You can check out the bas_c_evt_handler() in the ble_app_hrs_c to see how that function confirms receiving data from the battery service for reference on the central side (The battery level service can be found in the ble_app_hrs peripheral example). Note that the ble_app_blinky_c (and ble_app_blinky peripheral example) uses a service as well in the LED Button service.

You could also set your central device to disconnect whenever the data from this service has been received by the central by calling the disconnect function after, for example, the "Battery Level received" print in the ble_app_hrs_c example project.

Best regards,

Simon

RE: Not able to wake the board from deep sleep(System off)

davidm — Thu, 10 Oct 2019 03:26:28 GMT

Hi Simon

Yes, I want it to go to sleep after data transfer.But the issue is disconnecting within BLE_GAP_EVT_CONNECTED case. Here is the flow......Assuming we have a logic to check if data has been sent to the peripheral in BLE_GAP_EVT_CONNECTED case(Which I have to yet figure out how i am going to do that). The central board connects to the peripheral for the first time,it checks if data has been sent in BLE_GAP_EVT_CONNECTED case, if True then we disconnect and put it to sleep, but in this case, since it is the first time, it is false so it will stay connected,and even if I push the button again,data will be sent but BLE_GAP_EVT_CONNECTED case won't be triggered again, because the connection is still active. Unless I misunderstood something from your previous post.

RE: Not able to wake the board from deep sleep(System off)

Simonr — Tue, 08 Oct 2019 07:51:21 GMT

If you go to system OFF mode after disconnecting, you will have to connect to the peripheral device again upon wake up, which should trigger the BLE_GAP_EVT_CONNECTED event. Was it not the intention that you wanted to go to system OFF between data transfers?

Best regards,

Simon

RE: Not able to wake the board from deep sleep(System off)

davidm — Tue, 08 Oct 2019 03:31:15 GMT

Hi Simon

My understanding is BLE_GAP_EVT_CONNECTED case will be only executed the first time when the board is connected to the peer device.After I push the button to send the data, the BLE_GAP_EVT_CONNECTED event won't be triggered again. Correct me if I am wrong or maybe I misunderstood you.In short, that didn't work for me.

RE: Not able to wake the board from deep sleep(System off)

Simonr — Mon, 07 Oct 2019 11:52:40 GMT

Hi David

Seeing as you want the application to go to sleep after a transfer is complete, you should make the central disconnect from the peripheral when the data transfer between them is complete. So after that operation is complete/successful, you should call sd_ble_gap_disconnect in the BLE_GAP_EVT_CONNECTED case in ble_evt_handler(). Then, after you have disconnected successfully, you should go to sleep using the sleep_mode_enter() function, as this function prepares wake-up buttons for you so that the device will wake up if you press any buttons.

I also suggest that you put in a logger message or similar in order to see that the connection, data transfer, and disconnection events are successful, using a terminal and NRF_LOG_INFO or something similar.

Best regards,

Simon

RE: Not able to wake the board from deep sleep(System off)

davidm — Sun, 06 Oct 2019 21:09:01 GMT

Hi Simon

devzone.nordicsemi.com/.../3122.main.c

Yes, I was able to save the conn_handle. I have attached my current main.c below.

RE: Not able to wake the board from deep sleep(System off)

Simonr — Fri, 04 Oct 2019 11:39:39 GMT

Hi David

Were you able to save the conn_handle and use it for disconnection? Could you post your current main.c file so I can get a better overview of how you're handling the various events?

I was initially thinking that you post go to sleep when the button_event_handler is done, your device has disconnected successfully and goes back into the main() function, as that would set a definitive end, making the code easier to read. But I'd like to get a look to see if that makes any sense in this case.

Best regards,

Simon

RE: Not able to wake the board from deep sleep(System off)

davidm — Fri, 04 Oct 2019 03:45:28 GMT

Hi Simon

I was scanning and connecting to a peripheral before disconnecting, I was not saving the connection_handle in beginning.

This time I tried to disconnect after data is sent in button_event_handler and put to sleep in BLE_GAP_EVT_DISCONNECTED case in ble_evt_handler , that didn't work either,it disconnect but , it doesn't go to sleep at all.

Where outside of button_event_handler were you thinking?

RE: Not able to wake the board from deep sleep(System off)

Simonr — Thu, 03 Oct 2019 08:04:08 GMT

Hi David

Do you start scanning and connect to a peripheral at any point before this though? You can't disconnect if you're not connected already. You'll also get the conn_handle upon connecting to another device, as the conn_handle is in the initial message. You'll have to save and use this in calls that require it. I believe just about any of our examples using BLE saves the conn_handle upon connection though.

On a somewhat unrelated note, I think you should put the disconnection and sleep events outside of the button_event_handler, and rather do these operations after the button_event_handler.

Best regards,

Simon

RE: Not able to wake the board from deep sleep(System off)

davidm — Thu, 03 Oct 2019 03:03:13 GMT

Thank you Simon.

I have been trying to play with code a bit, now my challenge is getting connection_handle instance in button_event_handler.I am trying to the board to sleep after the data has been successfully sent, but we don't have access to the conn_handle in order to disconnect in button_event_handler. See code below

case LEDBUTTON_BUTTON_PIN:
            err_code = ble_lbs_led_status_send(&m_ble_lbs_c, button_action);
            if (err_code != NRF_SUCCESS &&
                err_code != BLE_ERROR_INVALID_CONN_HANDLE &&
                err_code != NRF_ERROR_INVALID_STATE)
            {
                APP_ERROR_CHECK(err_code);
            }
            if (err_code == NRF_SUCCESS)
            {
                NRF_LOG_INFO("LBS write LED state %d", button_action);
                //sd_ble_gap_disconnect(conn_handle,BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION); 
                sleep_mode_enter();
            }
            break;

RE: Not able to wake the board from deep sleep(System off)

Simonr — Tue, 01 Oct 2019 08:20:19 GMT

Okay, thank you for clarifying! Then I guess you want to disconnect (using sd_ble_gap_disconnect) after the data has been transferred, so call the disconnect when the data has been received by the peripheral and then go to sleep after you've disconnected.

As for the data being sent depending on what button you push, I don't think you can set this with the same button push you wake up the device with. So I think you either have to press the button twice, once for wake-up and once for what data you are to send or holding the button and set an "if BTN1 is held, send data 1" after the device has woken up.

Best regards,

Simon

RE: Not able to wake the board from deep sleep(System off)

davidm — Tue, 01 Oct 2019 04:08:00 GMT

I can see SUPERVISION_TIMEOUT could have been useful but in my case I want it to go to sleep right after the data has been sent. So basically when you push the button,it wakes up, connects to peer board, sends data to it(data sent will depend on the button pushed, that is why I was trying to put this on button event handler ), and then it goes back to sleep.In other words, the board will be forced out of connection as a result of the central going to sleep.

RE: Not able to wake the board from deep sleep(System off)

Simonr — Mon, 30 Sep 2019 11:38:49 GMT

Yes, I just mentioned SCAN_DURATION if it is relevant to you that if the device isn't able to connect to another one in a given amount of time, it might want to go back to sleep.

SUPERVISION_TIMEOUT however, should be able to disconnect you from an inactive connection so you can go to sleep upon disconnection from the peripheral. Remember that when you go to deep sleep (System OFF) mode, the wake-up call will trigger a reset, which is why you can't start the main loop by going to sleep. If you want it to do something when it wakes up, you'll have to add that before going to sleep.

Best regards,

Simon

RE: Not able to wake the board from deep sleep(System off)

davidm — Sun, 29 Sep 2019 22:51:07 GMT

Hi Simon

Yes, I want it to go to sleep by itself but after it had sent the data to the connected peer device. That is why I tried to put sleep_mode_enter() in button_event_handler after ble_lbs_led_status_send() (which didn't work).

Correct me if I am wrong, my understanding is setting SCAN_DURATION to a certain time, if it gets connected before expiration time it will never go to sleep.

In other words what I want is the central to always be in deep sleep. When you push button 1 or button 2 the device should wake up, send data to the connected peer device and then go back to sleep.

RE: Not able to wake the board from deep sleep(System off)

Simonr — Fri, 27 Sep 2019 07:08:42 GMT

Hi David

So you want it to go to deep sleep by itself after the application has scanned/received for some time? In that case, you should set the SCAN_DURATION to however long you want it to scan before the device goes to sleep, as well as setting the SUPERVISION_TIMEOUT to however long you'd like a connection to be inactive before the central disconnects and goes to sleep.

Or is the issue that you're not able to get the device into deep sleep mode at all? Because on my end, after just a few tweaks to your code, the application now goes to sleep if I press button 1 on the DK, and wakes up by a press of any button.

Best regards,

Simon

RE: Not able to wake the board from deep sleep(System off)

davidm — Fri, 27 Sep 2019 02:46:29 GMT

Hi Simonr

Thank you for the response. The ble_app_blinky_c example doesn't seem to have that implementation, the bsp_event_handler is something that I added to the app in an attempt to put it to sleep. Also, I removed sleep_mode_enter() out of main loop, and put it inside button_event_handler() after a button is pressed (basically when the button is pressed, it transmit the data and after the transmission is successful it goes back to sleep) but still that didn't work.

I have also tried to do like how they are doing in Ble app template example, but that didn't help (that's where I took bsp_event_handler).

RE: Not able to wake the board from deep sleep(System off)

Simonr — Thu, 26 Sep 2019 11:39:45 GMT

Hi David

First of all, by setting sleep_mode_enter() function before the init functions causes a fatal error, and the chip to just reset over and over. Next, by setting the sleep_mode_enter() function in the main loop will cause the application to go to sleep every time it wakes up, as it resets when it wakes up, and starts the main loop from the beginning, causing the device to never be able to scan.

The ble_app_blinky_c example kind of already implements what you're looking for, as it starts out with scanning, then goes to sleep when you press button 1 (see bsp_event_handler), and it only wakes up by either pressing the reset button or button 2 which is set to wake it up.

Best regards,

Simon