pyAutoPort 1.3.1

A tool automating UART and ADB interaction

Quick Start

pyAutoPort is a collection of BASH/ZSH tools that makes it easier and more consistent to communicate with a Device Under Test (DUT) connected via UART or ADB. It's built for embedded system engineers to automate testing.

These commands can be executed directly from the terminal as system commands.

pyAutoPort also provides Python APIs that automatically handles opening and closing the UART connection, incorporates a defined timeout for reading responses, and gracefully handles potential decoding errors by including undecodable data in hexadecimal format.

Installation

Install pyAutoPort-related commands using:

pip install pyAutoPort

Run this command INSIDE JUPYTER if you want to use this in a Jupyter notebook or Jupyter Lab.

Set Configuration

To specify the UART port and baudrate or ADB Serial Number, define them in environment variables like this:

• Linux/MacOS

export TESTER_UART_PORT="/dev/ttyACM0"
export TESTER_UART_BAUDRATE=1250000
export TESTER_ADB_PORT=Serial_number

• Windows Command Prompt

set TESTER_UART_PORT="COM0"
set TESTER_UART_BAUDRATE=1250000
set TESTER_ADB_PORT=Serial_number

• Windows PowerShell

$Env:TESTER_UART_PORT = 'COM0'
$Env:TESTER_UART_BAUDRATE = 1250000
$Env:TESTER_ADB_PORT = Serial_number

adb devices -l can get Serial_number. Default adb shell if TESTER_ADB_PORT not been setted.

Sending UART Commands

Calling from Command Line

Send UART commands and receive replies with:

uart_send ${MESSAGE}

For example, you should be able to see "connected" in the output after running:

uart_send "echo connected"

You don't need to send other commands to get output; uart_send will return the output.

For additional information, refer to the Basic Mode section.

Calling from Python

The write_and_read_uart function allows you to send text to a UART interface and retrieve any response received until a specified timeout occurs.

Function Signature:

def write_and_read_uart(text, uart_timeout, port=None, baudrate=None):
    """Writes text to the UART and reads all available lines until a timeout.

    Args:
        text: The text to write to the UART.
        uart_timeout: The timeout for UART operations (in seconds).
        port: The UART port to use (e.g., '/dev/ttyUSB0'). If None, the default port is used.
        baudrate: The baudrate to use (e.g., 115200). If None, the default baudrate is used.

    Returns:
        A string containing the reply received from the UART.  If any received data could not be decoded as UTF-8, its hexadecimal representation is included in the returned string.
    """

Basic Usage:

To send a simple command and retrieve the response, you can use the following:

response = write_and_read_uart("AT+INFO\n", 2.0)  # Sends "AT+INFO\n" and waits up to 2 seconds for a response.
print(response)

Specifying Port and Baudrate:

If your UART interface isn't using the default port or baudrate, you can specify them explicitly:

response = write_and_read_uart("AT+VERSION\n", 1.5, port="/dev/ttyACM0", baudrate=9600)
print(response)

Important Considerations:

• Newline Characters: The function requires a newline character (\n) to be appended to the text being sent. The UART device typically expects this to signal the end of the command.
• Timeout: The uart_timeout parameter is crucial. Set it long enough for the device to complete its operation and send a reply, but not so long that the program waits unnecessarily.
• Decoding Errors: If the UART device sends data that cannot be decoded using UTF-8, the undecodable portion is represented in the response string using its hexadecimal equivalent. This helps in debugging communication issues. You might need to investigate the device's documentation to understand the expected data format.
• Default Port and Baudrate: The function uses get_default_port() and get_default_baudrate() to determine the default values if port and baudrate are not provided. Make sure these functions are defined and configured correctly.

Interacting with ADB

While adb shell xxx is widely used to run shell commands from scripts without user interaction, direct interaction via the command-line interface (CLI) is necessary sometimes, especially when running an interactive app behind ADB.

This package provides tools for keeping an ADB session open and interacting with it directly from a script without being trapped by adb shell.

Open A Persistent ADB Session

adb_open&

Send Commands to ADB Session

adb_send some command
adb_send another command

Close ADB Sessions

adb_close

These commands simplify the process of sending and receiving data to and from your DUT using UART and ADB in various testing scenarios.

For additional information, refer to the Basic Mode section.

Interacting support TeraTerm-compatible commands

TeraTerm Mode Support TTL commands which can making automation scripting easier.

TeraTerm Mode Start

Create a Session, Use connect command to configure the connection.

In a Session, multiple different types of connections can be connected simultaneously without affecting each other.

• Linux/MacOS

session_start&

• Windows

start /B session_start

Send TTL commands

Following commands supported

• getenv
• setenv
• connect
• logstart
• logwrite
• logstop
• send
• mapuse
• waitln
• disconnect

For additional information, refer to the TeraTerm Mode section.

Session Stop

At the end of the session, all connections will be disconnected and the log will be saved if necessary.

session_stop

Basic Mode

Basic Mode provides commands integreated into Shell or Windows Command Propmt or PowerShell. Communication on UART and ADB are wrapped as command line commands.

Basic usage of Basic Mode can be found in Quick Start section. The following part focuses on additional information.

UART Communication

The uart_send command facilitates interaction with UART. Its usage is as follows:

usage: uart_send [-h] [-t TIMEOUT] text [text ...]

positional arguments:
  text                  Text to be sent via UART

options:
  -h, --help            Display this help message and exit
  -t TIMEOUT, --timeout TIMEOUT
                        Time to wait before stopping reading

When using uart_send, it will continuously print text received from UART until there is no new text within a 0.5-second interval. To extend the duration before stopping, specify a new timeout value using -t TIMEOUT.

IMPORTANT: If UART continues to print text, especially in scenarios with enabled debugging logs, you may need to press Ctrl-C to stop forcefully.

ADB Communication

Unlike UART, interacting with ADB involves a three-step process: opening an ADB session, interacting within the session, and finally closing the ADB session.

To initiate an ADB session, use the commands adb_open or adb_reopen. If a previous session was not closed safely, it's recommended to use adb_reopen for recovery.

IMPORTANT: Run adb_open& to open the session in the background. Otherwise, using adb_open alone will block further command execution since it is a blocking command call.

For interaction with ADB, employ the adb_send command with the following usage:

usage: adb_send [-h] [-t TIMEOUT] text [text ...]

positional arguments:
  text                  Text to send via ADB

options:
  -h, --help            show this help message and exit
  -t TIMEOUT, --timeout TIMEOUT
                        Time to wait before stopping reading

The adb_send command will continuously print text received from ADB until no new text is received within a 1-second timeframe. To extend the timeout duration before stopping, use the -t TIMEOUT option.

IMPORTANT: In situations where ADB keeps printing text, such as when running logcat, you may need to press Ctrl-C to stop forcefully.

TeraTerm Mode

TeraTerm Mode Support TTL commands on Linux or Windows CLI via adb or uart.

getenv

Gets an environment variable.

getenv <envname>

setenv

Sets an environment variable.

setenv <envname> <strval>

connect

Start one connection or switch other connection. If switch other connection, the existed connection will not be disconnected.

connect [uart|adb]

Example:

connect adb     -> ADB connection create
send xxx        -> send xxx via ADB
connect uart    -> UART connection create and switch UART
send xxx        -> send xxx via UART
connect adb     -> switch ADB
send xxx        -> send xxx via ADB

logstart

Start to Saving Received Messages to specified file. This command must be used after one connection has been already created.

logstart <filename>

• Add TimeStamp in log

set_timestamp
logstart <filename>

logwrite

Writes a string to the log file.

logwrite <string>

logstop

Stop saving logs into the log file.

logstop

send

Send commands via current connection. Received Messages will be printed on CLI.

send <date1> <date2> ...

mpause

Pauses.

mpause <milliseconds>

waitln

Waits a line that contains string. Pauses until a line which contains one of the character strings is received from the host, or until the timeout occurs.

set_timeout 2
waitln <string1> [<string2> ...]

disconnect

Stop specified connection.

disconnect [uart|adb]

Some commands will be supported in the future.

How to Contribute

See contributing guidelines for details. commit guidelines may also be helpful.

LICENSE

This project is under BSD-3 license.

Credits

We express our gratitude to all contributors for their valuable contributions to pyAutoPort!

Maintainers

• Yu GU [e-mail] (Basice Mode)
• Shuang LIANG [e-mail] (TeraTerm Mode)

Contributors

Happy coding!