Android-RasPi-WifiP2P-Communication

This project provides two applications for setting up a Wifi Direct connection between a Raspberry Pi 3b and an android
phone.
Contains config scripts as well code for setting up a connection, setting up a TCP socket, and exchanging data
on both the android and the pi.

Establish a P2P connection

To establish a P2P connection between the raspberry pi and an android phone two steps are required:

1. Setup the Raspberry Pi and start the P2P server on the Raspberry Pi
2. connect to the raspberry pi using Wi-Fi direct from the raspberry pi

Raspberry Pi P2P Server

Setting up the Raspberry Pi

To be able to establish a P2P connection between a Raspberry Pi and an android phone a few packages need to be installed
some configurations must be changed. For that reason the repository contains the installation script raspberry-config.sh.
After running this script the Raspberry Pi will lose the current Wi-Fi connection. It's still possible to communicate
with the Raspberry Pi using a wired connection.

Start the P2P Server

To start the P2P connector run this command:

python3 pi_server/p2p_connector/wifi_direct_connetor.py [target_device_name]

The Raspberry Pi is now waiting for an incoming connection from the device with the device name 'target_device_name'.
After receiving a connection request from the android phone, the Raspberry Pi will establish a connection automatically. Now you can continue with the step Connect to the Raspberry Pi.

Remove P2P Group (disconnect from target device):

python3 pi_server/src/wifi_direct_connetor.py --remove-group

display usage text

python3 pi_server/src/wifi_direct_connetor.py -h

documentation

The documentation of the python code is hosted as Github Page.

Connect to the Raspberry Pi using Wi-Fi direct

After the P2P server on the Raspberry Pi was started it's possible to connect to it using Wi-Fi direct. There are two options for establishing a connection:

1. Use the android system settings

-> settings -> Wi-Fi -> open the dropdown menu (three vertical dots icon) -> Wi-Fi Direct -> choose the device name which was set in the raspberry-config.sh file

2. Use the P2P-Connector Android App which is provided by this project

Android App

Exchange data between the Raspberry Pi and the android phone

After the android phone is connected to the Raspberry Pi it is possible to send data using TCP sockets. On the Raspberry Pi a server socket should to be started. After that it's possible to connect to this socket from an android app. The Android-RasPi-WifiP2P App which is provided by this project can has already implemented a TCPSocket class and an example Activity which shows how a TCP connection could be established. The App is a good entrypoint for developing a Android P2P app using Wi-Fi direct.

links:

https://raspberrypi.stackexchange.com/questions/117150/issue-connecting-raspberry-pi-to-android-via-wifi-p2p
https://raspberrypi.stackexchange.com/questions/117718/how-to-connect-an-android-phone-and-a-raspberry-pi-through-wifi-direct-programma

https://github.com/CatalinPrata/funcodetuts/blob/master/AndroidTCPClient