diff --git a/src/main-hid.py b/src/main-hid.py
new file mode 100644
index 0000000..4eae9a4
--- /dev/null
+++ b/src/main-hid.py
@@ -0,0 +1,180 @@
+# Copyright 2025 PostalPortal LLC and Netsyms Technologies LLC
+#
+# Redistribution and use in source and binary forms, with or
+# without modification, are permitted provided that
+# the following conditions are met:
+#   1. Redistributions of source code must retain
+#      the above copyright notice, this list of conditions
+#      and the following disclaimer.
+#   2. Redistributions in binary form must reproduce
+#      the above copyright notice, this list of conditions
+#      and the following disclaimer in the documentation
+#      and/or other materials provided with the distribution.
+#   3. Neither the name of the copyright holder
+#       nor the names of its contributors may be used
+#       to endorse or promote products derived from
+#       this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+# CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES,
+# INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+# GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+# OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+# TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
+# WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+# THE POSSIBILITY OF SUCH DAMAGE.
+
+#
+# This version implements USB HID to receive the door command and send status.
+#
+
+from sys import stdin, exit
+from _thread import start_new_thread
+import machine
+from machine import Pin, USBDevice
+from utime import sleep
+import usb.device
+from micropython import const
+from usb.device.hid import HIDInterface
+
+print("PostalPoint(r) Shipping Kiosk Door Controller")
+print("Firmware version 1.2.0")
+print("USB HID build")
+
+led = Pin(25, Pin.OUT) # Onboard LED
+relay = Pin(4, Pin.OUT) # Relay control pin
+latchStatus = Pin(15, Pin.IN, Pin.PULL_DOWN) # Read status of door latch switch
+latchSend = Pin(14, Pin.OUT) # Send signal to latch switch
+latchNotifyCounter = 0 # Don't send latch status constantly
+latchNotifyInterval = 50 # Number of main loop executions between notifications
+uspsLock = Pin(1, Pin.IN, Pin.PULL_DOWN) # Read arrow lock switch
+uspsLockSend = Pin(0, Pin.OUT) # Send to arrow lock switch
+uspsLockOpen = False
+led.value(0)
+relay.value(0)
+uspsLockSend.value(1)
+
+# Read status of USPS arrow lock to see if it's NC or NO
+# The switch will be depressed when the lock is closed
+# Assume it's locked when power is turned on
+uspsLockValueWhenLocked = uspsLock.value()
+
+# Read if jumper is set to slow mode
+fastMode = True
+selectSlow = Pin(18, Pin.IN, Pin.PULL_DOWN)
+selectEmit = Pin(17, Pin.OUT)
+selectEmit.value(1) # Output on middle pin
+fastMode = selectSlow.value() != 1
+selectEmit.value(0) # Turn off pin, not needed after boot
+
+if fastMode:
+    print("Door mode: Fast")
+else:
+    print("Door mode: Slow")
+
+if uspsLockValueWhenLocked == 0:
+    print("Arrow lock switch: Normally Closed or Not Present")
+else:
+    print("Arrow lock switch: Normally Open")
+
+print("Boot complete")
+
+
+# VID and PID of the USB device.
+VID = 0xF055 # USB Vendor ID
+PID = 0x9999 # USB Product ID
+MANU = "PostalPortal LLC" # USB manufacturer string
+PROD = "PostalPoint Kiosk Controller" # USB product string
+INTERFACE = "PostalPoint" # Interface string
+
+class USBHIDInterface(HIDInterface):
+    # Very basic synchronous USB keypad HID interface
+
+    def __init__(self):
+        super().__init__(
+            bytes([
+                0x06, 0x69, 0xff,       # Usage Page (Vendor Defined)
+                0x09, 0x01,             # Usage (Vendor Usage 1)
+                0x19, 0x01,
+                0x29, 0x01,
+                0xa1, 0x01,             # Collection (Application)
+                0x15, 0x00,             #   Logical Minimum (0)
+                0x26, 0xff, 0x00,       #   Logical Maximum (255)
+                0x85, 0x01,             #   Report ID 1
+                0x09, 0x01,             #     Usage (Vendor Usage 1)
+                0x95, 0x01,             #     Report Count (1 byte)
+                0x75, 0x08,             #     Report Size (8 bits)
+                0x81, 0x00,             #     Input (Data,Ary,Abs)
+                0x85, 0x01,             #   Report ID 1
+                0x09, 0x01,             #     Usage (Vendor Usage 1)
+                0x95, 0x01,             #     Report Count (1 bytes)
+                0x75, 0x08,             #     Report Size (8 bits)
+                0x91, 0x01,             #     Output (Data,Ary,Abs)
+                0xc0                    # End Collection
+            ]),
+            set_report_buf=bytearray(1),
+            protocol=const(0x00),
+            interface_str=INTERFACE,
+        )
+
+    def on_set_report(self, report_data, _report_id, _report_type):
+        unlockDoor(False)
+
+    def send_data(self, data=None):
+        while self.busy():
+            machine.idle()
+        if data is None:
+            self.send_report(b'\x01\xFF')
+        else:
+            self.send_report(data)
+            
+usbinterface = USBHIDInterface()
+usb.device.get().active(False)
+usb.device.get().config(usbinterface, builtin_driver=True, manufacturer_str=MANU, product_str=PROD, id_vendor=VID, id_product=PID)
+usb.device.get().active(True)
+
+def unlockDoor(usps = False):
+    print("DO", end="")
+    led.value(1)
+    relay.value(1)
+    if usps == True:
+        usbinterface.send_data(b'\x01\x05')
+    else:
+        usbinterface.send_data(b'\x01\x04')
+    if fastMode:
+        sleep(0.5)
+    else:
+        sleep(10)
+    relay.value(0)
+    led.value(0)
+    print("OR")
+
+try:
+    while True:
+        if uspsLock.value() != uspsLockValueWhenLocked:
+            # Arrow lock override, open door, but then don't again until re-locked
+            if uspsLockOpen == False:
+                uspsLockOpen = True
+                print("USPS")
+                unlockDoor(True)
+        if uspsLock.value() == uspsLockValueWhenLocked:
+            uspsLockOpen = False
+        
+        latchSend.value(1)
+        if latchStatus.value() == 1:
+            usbinterface.send_data(b'\x01\x21')
+        else:
+            usbinterface.send_data(b'\x01\x20')
+        latchSend.value(0)
+            
+        sleep(0.1)
+
+except KeyboardInterrupt:                   # trap Ctrl-C input
+    terminateThread = True                  # signal second 'background' thread to terminate 
+    exit()
\ No newline at end of file
diff --git a/src/main.py b/src/main.py
index a14f2b1..0336ced 100644
--- a/src/main.py
+++ b/src/main.py
@@ -31,6 +31,10 @@
 # THE POSSIBILITY OF SUCH DAMAGE.
 
 
+#
+# This version communicates over serial.
+#
+
 from sys import stdin, exit
 from _thread import start_new_thread
 from utime import sleep
@@ -39,6 +43,7 @@ from machine import Pin
 sleep(2)
 print("PostalPoint(r) Shipping Kiosk Door Controller")
 print("Firmware version 1.1.0")
+print("Serial build")
 
 led = Pin(25, Pin.OUT) # Onboard LED
 relay = Pin(4, Pin.OUT) # Relay control pin