Can an android device be a peripheral?

[MichaelNordicUser]

It's clear an Android device can be a central, but I'm having a hard time finding any information indicating an Android device cab be a peripheral that an NRF52 could be programmed to connect to. I see samples of apps where an Android device can broadcast, but these apps are not actually peripheral apps.

[endnode]

You are having "hard time" to find this out? On the internet? By searching? Can you please tell me how you magically missed all the Google pages full of information? You are right that all the guides are focusing primarily on advertising but like ever second also continues with things like how to interact with devices which really connect to your Broadcaster (or Peripheral at that moment to be technically correct).

Some examples from top 20 hits on Google search:

• Talk by Android dev team explicitly talking about both Peripheral and Broadcaster.
• Q&A from this very forum talking about many details of Android GAP/GATT support and API.
• Youtube video (one of many) showing how easy it is to connect to Android phone in GAP Peripheral mode and use its GATT Server.
• One of many Android dev guides how to use GAP Peripheral and GATT Server in your app (this one in Xamarin framework).
• Kind of whitepaper page elaborating deeper on changes in BLE architecture since Android L.

GAP Peripheral mode is optional for Android devices and there is certain portion of devices which support BLE but only GAP Central (famous example is Nexus 5 with stock Android from Google - even HW and BT chipset is able to do it as verified in different custom ROMs and hacks). But today basically all new Android devices support BLE and support both GAP and GATT modes (Peripheral and Central, Server and Client). Simple test: download Nordic nRF Connect to your device, set-up Broadcaster and GATT Server and connect to it from another device (which plays GAP Central). Unless you have really bad luck in terms of phone it will work like a charm.