Scanning parameters for enocean PTM215b ble switch.

[WilliamJangren]

Hi! 

Im using a PTM215b ble switch from enocean to Control some leds on a nrf51dk. Everything works fine except that sometime nothing is happening when i press a button on the switch. 

I can see in a ble sniffer app on my phone that the switch sends a burst of 2 to 3 messages every time a button is pressed on the switch. Is there anyone that can help me understand what 

scanning parameters i should use? 

William

[Hung Bui]

Hi William, 

By default the Enocean switch will send 2-3 advertising packets (in 3 channels)  on every click on the switch (so in total 6-9 packets) .

To maximize the chance that the nRF51 can capture the packets, you should configure the nRF51 to listen all the time. This can be done by setting the scan window equal to the scan interval. 

[WilliamJangren]

Hi! 

Thanks for replying, I have tried this and the nrf51 still dosnt detect all packets. 

Is it possible that other advertising things like phones etc.is disturbing? And in that case whitelisting the enocean switch might solve my problem?

[Hung Bui]

If you are testing in an noisy environment, there is a chance that the packet get interfered. 

Using whitelist wouldn't help as the interference happens regardless if the address is whitelisted or not. 

How often do you see the issue ? 

You can check either the power consumption or radio notification, or monitor the pin of nRF52 to know if it's in the scanning mode all the time. 

[WilliamJangren]

Every time a advertise message is captured by the nrf51 the on_ble_evt function and BLE_GAP_EVT_ADV_REPORT case is executed. So there is no chance that the advertise message from the switch can be ignored because there are other devices that trigger these things? 

[Hung Bui]

The event will be queued, and you should receive event for each of the advertising packet it receives. How often do you observe the issue ? If you place the phone very close to the switch do you get better result ? 

What was your scan window and scan interval ? 

[WilliamJangren]

Hi again!

I tried different values on the scan window and interval and now it seems to work pretty good as long they are the same. I dont now whats was wrong yesterday but now the nrf51 capture Close to all adv messages.

Thank you for your time