I'm using an nrf24L01+ which is the one of the cheapest and most reliable 2.4GHz radios in the maker community. I'm using this in conjunction with the Atmega328 to make it function as a BLE radio advertiser.
The following is the repository I am using and is completely generic and works on top of the RF24 library by TMRh20:
Step 1: Connect the nrf24L01+ to the SPI pins of your specific Arduino. Choose and change the Chip enable (CE) and Chip select (CS) in the code corresponding to your connections
Step 2: Clone the repo and paste the RF24BLE folder in the folder "libraries" in the sketchbook area. e.g "Arduino/libraries/RF24BLE"
Step 3: Open the Arduino IDE and choose an example from the file->examples menu and upload any example.
Step 4: Download and install the app "
nrf Master control
" app from the Google Play Store on an Android device.
Step 5: Open the app and click on
and the advertised packet should be shown in the list in the app.