USB Serial support for the open-source firmware (#9)

* USB Serial support for the open-source firmware

lednamebadge.py

@@ -733,6 +733,71 @@ class WriteUsbHidApi(WriteMethod):
             WriteUsbHidApi.pyhidapi.hid_write(self.dev, sendbuf)
 
 
+class WriteSerial(WriteMethod):
+    """Write to a device with the open-source firmware via the USB serial port using pyserial.
+    """
+    _module_loaded = False
+    try:
+        import serial
+        _module_loaded = True
+        print("Module pyserial detected")
+    except:
+        pass
+
+    def __init__(self):
+        WriteMethod.__init__(self)
+        self.description = None
+        self.path = None
+        self.dev = None
+
+    def get_name(self):
+        return 'pyserial'
+
+    def get_description(self):
+        return 'Program a device with the open-source firmware, connected via USB, using the pyserial package.'
+
+    def _open(self, device_id):
+        import serial
+        self.description = self.devices[device_id][0]
+        self.path = self.devices[device_id][1]
+        self.dev = serial.Serial(self.path)
+        if self.dev:
+            print("Pyserial device initialized")
+
+        return self.dev is not None
+
+    def close(self):
+        if self.dev is not None:
+            self.dev.close()
+        self.description = None
+        self.path = None
+        self.dev = None
+
+    def _get_available_devices(self):
+        import serial.tools.list_ports
+        ports = serial.tools.list_ports.comports()
+
+        devices = {}
+        for port, desc, hwid in ports:
+            if desc == "n/a": 
+                continue
+            devices[port] = (f"{desc} ({hwid})", port)
+        return devices
+
+    def is_ready(self):
+        return WriteSerial._module_loaded
+
+    def has_device(self):
+        return self.dev is not None
+
+    def _write(self, buf):
+        if not self.dev:
+            return
+
+        print("Write using [%s] via pyserial" % (self.description,))
+        self.dev.write(buf)
+
+
 class LedNameBadge:
     _protocol_header_template = (
         0x77, 0x61, 0x6e, 0x67, 0x00, 0x00, 0x00, 0x00, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
@@ -945,7 +1010,7 @@ class LedNameBadge:
 
     @staticmethod
     def _get_auto_order_method_list():
-        return [WriteUsbHidApi(), WriteLibUsb()]
+        return [WriteUsbHidApi(), WriteLibUsb(), WriteSerial()]
 
     @staticmethod
     def _print_available_methods(methods):

tests/test_lednamebadge_select_method.py

@@ -11,6 +11,7 @@ class Test(abstract_write_method_test.AbstractWriteMethodTest):
         self.assertIn("'auto'", output)
         self.assertIn("'hidapi'", output)
         self.assertIn("'libusb'", output)
+        self.assertIn("'pyserial'", output)
 
         method, output = self.call_find(True, True, True, 'hidapi', 'list')
         self.assertIn("Known device ids with method 'hidapi' are:", output)