✨Set team number and robot name (#219)

* old code (not working)

* use correct txrx function

* return set value

pros/cli/v5_utils.py

@@ -290,3 +290,34 @@ def capture(file_name: str, port: str, force: bool = False):
         w.write(file_, i_data)
 
     print(f'Saved screen capture to {file_name}')
+
+@v5.command(aliases=['sv', 'set'], short_help='Set a kernel variable on a connected V5 device')
+@click.argument('variable', type=click.Choice(['teamnumber', 'robotname']), required=True)
+@click.argument('value', required=True, type=click.STRING, nargs=1)
+@default_options
+def set_variable(variable, value):
+    import pros.serial.devices.vex as vex
+    from pros.serial.ports import DirectPort
+
+    # Get the connected v5 device
+    port = resolve_v5_port(None, 'system')[0]
+    if port == None:
+        return
+    device = vex.V5Device(DirectPort(port))
+    actual_value = device.kv_write(variable, value).decode()
+    print(f'Value of \'{variable}\' set to : {actual_value}')
+
+@v5.command(aliases=['rv', 'get'], short_help='Read a kernel variable from a connected V5 device')
+@click.argument('variable', type=click.Choice(['teamnumber', 'robotname']), required=True)
+@default_options
+def read_variable(variable):
+    import pros.serial.devices.vex as vex
+    from pros.serial.ports import DirectPort
+
+    # Get the connected v5 device
+    port = resolve_v5_port(None, 'system')[0]
+    if port == None:
+        return
+    device = vex.V5Device(DirectPort(port))
+    value = device.kv_read(variable).decode()
+    print(f'Value of \'{variable}\' is : {value}')

pros/serial/devices/vex/v5_device.py

@@ -892,6 +892,36 @@ def sc_init(self) -> None:
         self._txrx_ext_struct(0x28, [], '')
         logger(__name__).debug('Completed ext 0x28 command')
 
+    @retries
+    def kv_read(self, kv: str) -> bytearray:
+        logger(__name__).debug('Sending ext 0x2e command')
+        encoded_kv = f'{kv}\0'.encode(encoding='ascii')
+        tx_payload = struct.pack(f'<{len(encoded_kv)}s', encoded_kv)
+        # Because the length of the kernel variables is not known, use None to indicate we are recieving an unknown length.
+        ret = self._txrx_ext_packet(0x2e, tx_payload, 1, check_length=False, check_ack=True)
+        logger(__name__).debug('Completed ext 0x2e command')
+        return ret
+
+    @retries
+    def kv_write(self, kv: str, payload: Union[Iterable, bytes, bytearray, str]):
+        logger(__name__).debug('Sending ext 0x2f command')
+        encoded_kv = f'{kv}\0'.encode(encoding='ascii')
+        kv_to_max_bytes = {
+            'teamnumber': 7,
+            'robotname': 16
+        }
+        if len(payload) > kv_to_max_bytes.get(kv, 254):
+            print(f'Truncating input to meet maximum value length ({kv_to_max_bytes[kv]} characters).')
+        # Trim down size of payload to fit within the 255 byte limit and add null terminator.
+        payload = payload[:kv_to_max_bytes.get(kv, 254)] + "\0"
+        if isinstance(payload, str):
+            payload = payload.encode(encoding='ascii')
+        tx_fmt =f'<{len(encoded_kv)}s{len(payload)}s'
+        tx_payload = struct.pack(tx_fmt, encoded_kv, payload)
+        ret = self._txrx_ext_packet(0x2f, tx_payload, 1, check_length=False, check_ack=True)
+        logger(__name__).debug('Completed ext 0x2f command')
+        return payload
+
     def _txrx_ext_struct(self, command: int, tx_data: Union[Iterable, bytes, bytearray],
                          unpack_fmt: str, check_length: bool = True, check_ack: bool = True,
                          timeout: Optional[float] = None) -> Tuple: