This sample demonstrates basic data read and write operations over a UART. The application creates a loopback interface that immediately echoes any data read from the receive (RX) buffer to the transmit (TX) buffer.
- Android Things compatible board with an available UART port
- Android Studio 2.2+
- FTDI TTL-232R or compatible USB-TTL converter
NOTE: Raspberry Pi 3 shares the UART pins between multiple ports, including the serial debugging console. Refer to the mode matrix for more details.
Check in the USB TTL cable's documentation for the TX and RX wire colors:
- connect the cable TX wire to the board RX pin
- connect the cable RX wire to the board TX pin
Build and install
- On Android Studio, click on the "Run" button.
If you prefer to run on the command line, type
./gradlew installDebug adb shell am start com.example.androidthings.loopback/.LoopbackActivity
Plug the USB-TTL converter into a host PC, start your favorite terminal program (minicom, screen, RealTerm, etc.), and connect to the USB-TTL port at 115200 baud.
Type characters into the terminal and observe them echo back to you from the device.
Copyright 2016 The Android Open Source Project, Inc.
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