diff --git a/build/arduino-esp.yml b/build/arduino-esp.yml
index ad51176e43..b78f99fb45 100644
--- a/build/arduino-esp.yml
+++ b/build/arduino-esp.yml
@@ -40,6 +40,8 @@ jobs:
       echo -e "exit\r\n\r\n\r\n" | cat > input.txt
       python3 serial_connect.py -i input.txt -o output.txt -b 115200 -p $(ESP8266_PORT) -d esp8266 -s
       rm input.txt
+      code=$(<exitcode.txt)
+      exit $code
     failOnStderr: true
     displayName: 'run_test'
 
@@ -96,6 +98,8 @@ jobs:
       echo -e "exit\r\n\r\n\r\n" | cat > input.txt
       python3 serial_connect.py -i input.txt -o output.txt -b 1000000 -p $(ESP32_PORT) -d esp32 -s
       rm input.txt
+      code=$(<exitcode.txt)
+      exit $code
     failOnStderr: true
     displayName: 'run_test'
 
diff --git a/testtools/UART_interface/azure_test_firmware_errors.py b/testtools/UART_interface/azure_test_firmware_errors.py
index 3631ef646c..68287d536d 100644
--- a/testtools/UART_interface/azure_test_firmware_errors.py
+++ b/testtools/UART_interface/azure_test_firmware_errors.py
@@ -2,4 +2,4 @@
 wifi_failure        = "AZ001"
 iot_init_failure    = "AZ002"
 sensor_init_failure = "AZ003"
-SDK_ERRORS = 0
\ No newline at end of file
+SDK_ERRORS = 0
diff --git a/testtools/UART_interface/esp_arduino_uart_interface.py b/testtools/UART_interface/esp_arduino_uart_interface.py
index 1de51b8771..042014d206 100644
--- a/testtools/UART_interface/esp_arduino_uart_interface.py
+++ b/testtools/UART_interface/esp_arduino_uart_interface.py
@@ -3,10 +3,6 @@
 import time
 try:
     from testtools.UART_interface.base_uart_interface import uart_interface
-except:
-    from base_uart_interface import uart_interface
-
-try:
     import testtools.UART_interface.azure_test_firmware_errors as azure_test_firmware_errors
     import testtools.UART_interface.serial_settings as serial_settings
     import testtools.UART_interface.serial_commands_dict as commands_dict
@@ -14,6 +10,7 @@
     import azure_test_firmware_errors
     import serial_settings
     import serial_commands_dict as commands_dict
+    from base_uart_interface import uart_interface
 
 
 # ------- global usecase fcns -------
@@ -24,10 +21,13 @@ def check_sdk_errors(line):
     local_line = line.lower()
     if "error" in local_line or "fail" in local_line:
         if "epoch time failed!" in local_line: # don't count NTP retries.
-            pass
+            azure_test_firmware_errors.SDK_ERRORS += 0
         else:
             azure_test_firmware_errors.SDK_ERRORS += 1
 
+# missing test_failures method, may not need due to this being a sample,
+# not a series of tests
+
 def check_firmware_errors(line):
     if azure_test_firmware_errors.iot_init_failure in line:
         print("Failed to connect to saved IoT Hub!")
@@ -117,7 +117,6 @@ def serial_read(self, ser, message, file, first_read=False):
             except:
                 return None
 
-    # Note: the buffer size on the mxchip appears to be 128 Bytes.
     def write_read(self, ser, input_file, output_file):
         if 'esp32' in serial_settings.device_type:
             serial_settings.bits_to_cache = 800
@@ -160,5 +159,7 @@ def write_read(self, ser, input_file, output_file):
 
                 # forward failed callbacks to SDK_ERRORS
                 azure_test_firmware_errors.SDK_ERRORS += self.messages_sent - self.message_callbacks
+                with open('exitcode.txt', 'w') as fexit:
+                    fexit.write('%d' %azure_test_firmware_errors.SDK_ERRORS)
 
-                output_file_obj.close()
+                output_file_obj.close()
\ No newline at end of file
diff --git a/testtools/UART_interface/mxchip_settings.py b/testtools/UART_interface/mxchip_settings.py
deleted file mode 100644
index e69de29bb2..0000000000
diff --git a/testtools/UART_interface/mxchip_uart_interface.py b/testtools/UART_interface/mxchip_uart_interface.py
index 5259c0c4c3..734221dc7d 100644
--- a/testtools/UART_interface/mxchip_uart_interface.py
+++ b/testtools/UART_interface/mxchip_uart_interface.py
@@ -50,7 +50,7 @@ def check_firmware_errors(line):
 
 # ------- interface class -------
 class mxchip_uart_interface(uart_interface):
-
+    # Note: commands on MXCHIP have line endings with \r AND \n
     # If there is a sudden disconnect, program should report line in input script reached, and close files.
     # method to write to serial line with connection monitoring
     def serial_write(self, ser, message, file=None):
diff --git a/testtools/UART_interface/serial_connect.py b/testtools/UART_interface/serial_connect.py
index c71cd27c09..6c729d2d16 100644
--- a/testtools/UART_interface/serial_connect.py
+++ b/testtools/UART_interface/serial_connect.py
@@ -18,8 +18,8 @@
     import mxchip_uart_interface
     import esp_arduino_uart_interface
 
-# Note: commands on MXCHIP have line endings with \r AND \n
-# Notes: This is designed to be used as a command line script with args (for automation purposes) to communicate over serial to a Microsoft mxchip device.
+# Note: This collection of scripts is designed to be used as a command line script with args (for automation purposes)
+# to communicate over serial to Azure IoT C SDK supported devices.
 
 uart = None
 
@@ -28,7 +28,6 @@ def usage():
     usage_txt = "serial_connect.py usage: \r\n"
     for commands in commands_dict.cmds:
         usage_txt += " - %s: " %commands + commands_dict.cmds[commands]['text'] + "\r\n"
-
     return usage_txt
 
 def parse_opts():
@@ -75,8 +74,7 @@ def check_firmware_errors(line):
         azure_test_firmware_errors.SDK_ERRORS += 1
 
 
-# If there is a sudden disconnect, program should report line in input script reached, and close files.
-# method to write to serial line with connection monitoring
+# Method to write to serial line with connection monitoring
 def serial_write(ser, message, file=None):
 
     # Check that the device is no longer sending bytes
@@ -178,13 +176,10 @@ def run():
             if len(output) > 4:
                 print(output)
 
+    if 'rpi' in serial_settings.device_type or 'raspi' in serial_settings.device_type:
         # for rpi, transfer pipeline/artifact files from agent to device
         # get filepath, walk it
         # for each file, send rz, then sz file to rpi port
-
-
-
-    if 'rpi' in serial_settings.device_type or 'raspi' in serial_settings.device_type:
         uart = rpi_uart_interface.rpi_uart_interface()
     elif 'mxchip' in serial_settings.device_type:
         uart = mxchip_uart_interface.mxchip_uart_interface()