add getRssi() and Rssi related callback

[hathach]

No description provided.

[baramuse]

Totally in for this one !
Still a bit new to the BT stack, will it give us the possibility to "measure" the distance between the devices ?
Is that a big job ?

[hathach]

not a big job, but I couldn't find time to work on this lib just now. You can find my hint here in the forum meanwhile

https://forums.adafruit.com/viewtopic.php?f=53&t=139645&p=691943&hilit=nrf52+rssi#p691943

[baramuse]

I actually started digging in the code and found the sd_ble_gap_rssi_start which I'm calling.
Now I've read the eventHandler code in BLEGap.cpp and it does not handle the BLE_GAP_EVT_RSSI_CHANGED event.
Is there a way to have an (sub?) eventHandler (like void BLEGap::_eventHandler(ble_evt_t* evt) in the sketch so I can catch those events ?

(oh and thanks for the answer :) )

[hathach]

you must call it within connection callback, I guess it must be called asap. Nordic docs doesn't mention this, I have been confusing like you before.

[baramuse]

Thanks for the tip, i'll start when connected then.
Any tips for hooking an event listener instead of constantly reading the last sample value ?

[hathach]

no we current doesn't have something like setBleEventCallback(), but may add it later on for user to work on unimplemented features. Much nicer than modifying the bsp code, which is a horrible lengthy code.

Update: #181

[baramuse]

Ok at least i know :)
I'll start by reading frequently the rssi value, then I'll see if I implement the event callback !

Thanks again !

(btw is that a good way to detect the proximity of an object ? I want to set leds depending on the proximity of a remote - an iPhone in this case)

[hathach]

proximity requires some processing filter and math calculation stuff, there is an example written by Kevin in the example/projects folder. He has more exp than me in this field. You may want to check that out.

[hathach]

implemented