serial_echo
===========
**Source code:** `serial_echo.py <https://chromium.googlesource.com/chromiumos/platform/factory/+/refs/heads/main/py/test/pytests/serial_echo.py>`_

Checks the communication between DUT and SMT test fixture.

SMT has a test fixture, which communicates with DUT via serial port.
This test is to make sure that the serial port works as expected.

It can also be used to send a command to the fixture before/after a test.

dargs:
  serial_param: a dict of parameters for a serial connection. Should contain
        'port'. For other parameters, like 'baudrate', 'bytesize', 'parity',
        'stopbits' and 'timeout', please refer pySerial documentation.
  send_recv: [send, recv]. send is a char for the DUT to send to
      a fixture. And recv is the expected one-char response from the fixture.


Test Arguments
--------------
.. list-table::
   :widths: 20 10 60
   :header-rows: 1
   :align: left

   * - Name
     - Type
     - Description

   * - serial_param
     - dict
     - a dict of parameters for a serial connection. Should contain "port". For other parameters, like "baudrate", "bytesize", "parity", "stopbits" and "timeout", please refer pySerial documentation.

   * - send_recv
     - list
     - (optional; default: ``['à', 'á']``) [send, recv]. send is a char for the DUT to send to a fixture MCU. And recv is the expected one-char response from the fixture.