Step 1: Arduino Side
- Arduino leonardo (Im used pro micro)
- A bluetooth module (HC05 or HC06)
HC05/06 connected to the leonardo Rx/Tx pins
Arduino just connected to the Raspberry Pi USB port
How it work:
The received characters transmitted to the RPI.
The "return" and "backspace" characters cannot received from the android keyboard, so im used two rarely used characters ($, &) to simulate "backspace" and "return".
Of course, you can change it.
Step 2: App Inventor Side.
The app is very simple.
There is only a bluetooth connection button, a text, and the "return", "backspace" buttons.
How it works:
When tap on the textbox, the android keyboard show up, you can start typing.
The clock module time interval changed to 1ms, so the android send the typed character
immediately to the arduino, and appear on the RPI monitor.
For mor details and arduino code dwonload link, check the video and video details.