Communication between App inventor 2 and Raspberry pi via usb?

Question

I plan to create an android app that can take pictures and send them to a Raspberri pi 2.

Even if I can use a Raspberri pi 3 or connect a bluetooth usb or wifi, I prefer to have a communication via usb only.

What is the best option for a simple html, css and js based application like App inventor?

I tried some app supposed to communicate by OTG cable but not working, may be my phone (chinese one) is not compatible.

I was thinking connecting rj45 to android, but look complicated.

Answer 1

I know most people will use wifi but for special projects we may need to communicate via usb. I've finally found, for those who are looking, here are the steps:

1. ssh on the raspberry pi or use screen and then:
   Make the ip static:

   sudo nano /etc/network/interfaces
   add:

   allow-hotplug usb0
   iface usb0 inet static 
   address 192.168.42.75
   netmask 255.255.255.0
   network 192.168.42.0
   broadcast 192.168.42.255
   gateway 192.168.42.1
   

   And/Or: ............// for me work with both
   sudo nano /etc/dhcpcd.conf
   add:
   

   interface usb0
   static ip_address=192.168.42.75/24
   static routers=192.168.42.1
   static domain_name_servers=192.168.42.1
   

   Replace the IP address (change 75) with a free IP address between the range 2-254.

2. Reboot and connect the Pi to the Android phone.

3. On the phone activate USB Tethering:
   Settings> Network & Internet > Tethering & Mobile Hotspot

4. Use SSH_CLIENT extension in App Inventor to send your commands:
   https://github.com/aluis-rcastro/AI2_ANDROID_SSH_CLIENT_EXTENSION