Alert notification on nrf51822

[Rahul Sahu]

Hi,
I need help with alert notification service. I am working on alert notification example provided in the SDK 12.3.0 with S130. I tried this example on nrf51422 development board and it is working. After changing to RAM ORIGIN = 0x20002080, LENGTH = 0x1F80 and Stack Size to 512 in gcc_startup_nrf51.s file, I am able to make this example work on nrf51822 evaluation board (pca10001) as well. But when I program this code on a PTR5518A module which is also nrf51822, my module is advertising and when I try to connect it is getting disconnected. The error log on MCP is as follows.

"Connected to E3BA04DDFDBD
Lost connection to device. Reason: BTLE_CONN_FAILED_TO_BE_ESTABLISHED
SERVER: Received packet HciEvent: eventCode=0x0A - HciEvent: eventCode=0x0A
SERVER: Received Link Loss "

1. Is this due to any power failure, I am using 10uf and 0.1uf capacitors across VCC and GND.
2. Is there any other configuration I am missing to make it work on nrf51822 (PTR5518A).
3. I see there is a log uart initialized, is this only for debug or is it being used for anything else while connecting. I am using P0.8 and P0.9 for RX and TX and is left open.
4. Any suggestions for power consumption will be helpful.

Thanks in advance.

[Sigurd]

Hi,

Do you have the same problem with other BLE examples also? e.g. ble_app_uart ? What revision is the nRF51 chip used on the PTR5518A module ? Note that revision 1 of the nRF51-series have anomalies that will give issues with newer softdevices(such as the one used in SDK 12). You should also try to debug the nRF51 and see if you are running into the error-handler. See this post about debugging.

[Rahul Sahu]

Hi, This problem is happening with alert notification example only. I have tried ble_app_uart example and it is working on PTR5518A module. After porting alert notification to ble_app_uart example, this is working. Still trying to find the original problem. Do you know what is the use of nrf_log in alert notification example. It seems that if I close the uart and then if I try to connect my module gets disconnected. What is the role of app_uart in alert notification service ?

[Sigurd]

nrf_log is used for printing logs over the UART and/or Segger RTT SWD interface. You can enable/disable this by setting the NRF_LOG_ENABLED in sdk_config.h. app_uart is a library used together with the uart drivers.

[Rahul Sahu]

Thank you for your reply. Do you know any central code for alert notification that i can use on another nrf51822 module. my purpose is to send alert between two PTR5518A modules using alert notification profile. Any suggestion for central code will be helpful.

[Sigurd]

The ble_app_alert_notification example implements the client role on a peripheral device. Note that MCP(Master Control Panel) is deprecated, and nRF-Connect could instead be used for testing this example(running the server role as a central). See this page. If you download SDK 13, you can find the .ncs file for nRF-Connect in the ble_app_alert_notification example folder.

See this answer regarding the different BLE role of the devices runing this example.