Project import generated by Copybara.

Tag: #compatibility
Bug: 189117116
Test: NA
PiperOrigin-RevId: 374987840
Change-Id: I1b512359e184ddc47145aa9339ddf3c75e28a2dc

1 files changed, 78 insertions, 0 deletions

diff --git a/system/blueberry/utils/arduino_base.py b/system/blueberry/utils/arduino_base.py
new file mode 100644
index 0000000000..37c9146033
--- /dev/null
+++ b/system/blueberry/utils/arduino_base.py
@@ -0,0 +1,78 @@
+"""Base class for Blueberry controllers using Arduino board.
+
+This module uses pyserial library to communicate with Arduino UNO board.
+
+About Arduino code, please refer to the code of following Arduino project:
+Internal link
+"""
+
+import time
+from mobly.signals import ControllerError
+import serial
+
+
+class ArduinoBase(object):
+  """Implements an Arduino base class.
+
+  Attributes:
+    serial: serial object, a serial object which is used to communicate with
+      Arduino board.
+  """
+
+  def __init__(self, config):
+    """Initializes an Arduino base class."""
+    self._verify_config(config)
+    self.serial = serial.Serial(config['arduino_port'], 9600)
+    self.serial.timeout = 30
+    # Buffer between calling serial.Serial() and serial.Serial.write().
+    time.sleep(2)
+
+  def _verify_config(self, config):
+    """Checks the device config's required config parameters.
+
+    Args:
+      config: dict, Mobly controller config for ArduinoBass. The config should
+        include the key "arduino_port" whose value is a string representing
+        Arduino board name. e.g. /dev/ttyACM0.
+    """
+    if 'arduino_port' not in config:
+      raise ControllerError('Please provide an Arduino board port for the'
+                            ' ArduinoBase in Mobile Harness config')
+
+  def _send_string_to_arduino(self, tx_string):
+    """Sends a particular string to communicate with Arduino.
+
+    The method requires that Arduino code can read string which is received from
+    a python serial object and then send the same string to the serial object.
+
+    An example of Arduino code:
+      String kRxString = "";
+      void setup() {
+        ...
+      }
+      void loop() {
+        if (Serial.available() > 0) {
+          kRxString = Serial.readString();
+          ...
+          Serial.write(kRxString.c_str());
+        }
+      }
+
+    Args:
+      tx_string: string, is used to be sent to Arduino port for making the
+        controlled device perform action. After Arduino receives the string, it
+        will send a response which is the same string.
+
+    Returns:
+      The time it takes for waiting a response, in seconds.
+
+    Raises:
+      ControllerError: raised if not received a response from Arduino.
+    """
+    self.serial.write(str.encode(tx_string))
+    start_time = time.time()
+    rx_string = self.serial.read_until(tx_string, len(tx_string)).decode()
+    if rx_string == tx_string:
+      return time.time() - start_time
+    raise ControllerError('Timed out after %ds waiting for the string "%s" from'
+                          ' Arduino.' % (self.serial.timeout, tx_string))