Help:breaks in slave node advertising

[frank zhang]

Hi All,

I need the slave node(S110) send advertising continuously and monitored by master node, so I set the advertising parameters as:

adv_params.type        = BLE_GAP_ADV_TYPE_ADV_NONCONN_IND;
adv_params.p_peer_addr = NULL;
adv_params.fp          = BLE_GAP_ADV_FP_ANY;
adv_params.interval    = 800;
adv_params.timeout     = 0;

The code compiled and run ok on the slave node. Then I modified the S120 code(ble_app_hrs_c) for the master node and monitor the advertising with it, the UART output information shows there are breaks in advertising, here is a sample log: ..... [2014:08:07:16:26:27]MAC:6F26E1DD94D8,RSSI:-47 [2014:08:07:16:26:28]MAC:6F26E1DD94D8,RSSI:-44 [2014:08:07:16:26:28]MAC:6F26E1DD94D8,RSSI:-42 [2014:08:07:16:26:34]MAC:6F26E1DD94D8,RSSI:-47 [2014:08:07:16:26:34]MAC:6F26E1DD94D8,RSSI:-44 [2014:08:07:16:26:35]MAC:6F26E1DD94D8,RSSI:-42 [2014:08:07:16:26:35]MAC:6F26E1DD94D8,RSSI:-47 [2014:08:07:16:26:36]MAC:6F26E1DD94D8,RSSI:-43 [2014:08:07:16:26:36]MAC:6F26E1DD94D8,RSSI:-42 [2014:08:07:16:26:37]MAC:6F26E1DD94D8,RSSI:-47 [2014:08:07:16:26:37]MAC:6F26E1DD94D8,RSSI:-44 [2014:08:07:16:26:38]MAC:6F26E1DD94D8,RSSI:-42 [2014:08:07:16:26:38]MAC:6F26E1DD94D8,RSSI:-46 [2014:08:07:16:26:39]MAC:6F26E1DD94D8,RSSI:-43 [2014:08:07:16:26:43]MAC:6F26E1DD94D8,RSSI:-47 .......

The logs shows the advertising stopped at 2014:08:07:16:26:28, and it started again at 2014:08:07:16:26:34, then it stopped at 2014:08:07:16:26:39 and started again at 2014:08:07:16:26:43. The full log shows the advertising is always in ON 5~6 secons and OFF 5~6 seconds state.

What I want is the slave node can send advertising twice a second,and the master node can know the slave node is alive with the advertising. For the problem, It's hard for me to check it's from slave node's advertising or the master node's listening. Could anybody give a suggestion on how to make it working? Thanks!

[John]

The easiest way to tell if your problem is with your advertiser or your central device is to capture the behavior in a sniffer. Nordic provides an easy way to convert your eval or dev kit into a sniffer. See here:

Sniffer download

[Ulrich Myhre]

It would really help if you could mention or tag your post with the S110 version, thanks!

[frank zhang]

I tried with the newest Softdevice s110_nrf51822_7.0.0_softdevice.hex+new SDK and an also older version s110_nrf51822_5.2.1_softdevice.hex + old SDK, both got the same results. My S120 is based on s120_nrf51822_1.0.0_softdevice.hex + SDK nrf51822_v5.2.0.39364.

[frank zhang]

I tried sniffer with my customized nrf51822 evb and failed to connect the com port, I guess this connection problem might be related to the clock as I need to configure NRF_CLOCK_LFCLKSRC_RC_250_PPM_TEMP_4000MS_CALIBRATION to make the evb run.

For the the problem I reported, as the master node can receive signals from other slave nodes when the advertising from the selected slave node stoped, which means the master node is working at the time, I guess the selected node should actually stops adverstising or the master node chooses to ignore this slave node, I want to know why and how to solve it.

[frank zhang]

I got a PCA10000 and successfully monitored the slave node with wireshark, the log shows there are no breaks in slave node's advertising, the problem should be at S120 side. I am curious why the master node can't get the advertising from one slave node continuously, when the problem occurs, the master node's RF is active as it can receive advertising from other nodes at the same time.