| #!/usr/bin/env python |
| # Copyright 2020 The Pigweed Authors |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| # use this file except in compliance with the License. You may obtain a copy of |
| # the License at |
| # |
| # https://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| # License for the specific language governing permissions and limitations under |
| # the License. |
| """Simple example script that uses pw_rpc.""" |
| |
| import argparse |
| import os |
| from pathlib import Path |
| |
| import serial # type: ignore |
| |
| from pw_hdlc_lite.rpc import HdlcRpcClient, default_channels |
| |
| # Point the script to the .proto file with our RPC services. |
| PROTO = Path(os.environ['PW_ROOT'], 'pw_rpc/pw_rpc_protos/echo.proto') |
| |
| |
| def script(device: str, baud: int) -> None: |
| # Set up a pw_rpc client that uses HDLC. |
| ser = serial.Serial(device, baud, timeout=0.01) |
| client = HdlcRpcClient(lambda: ser.read(4096), [PROTO], |
| default_channels(ser.write)) |
| |
| # Make a shortcut to the EchoService. |
| echo_service = client.rpcs().pw.rpc.EchoService |
| |
| # Call some RPCs and check the results. |
| status, payload = echo_service.Echo(msg='Hello') |
| |
| if status.ok(): |
| print('The status was', status) |
| print('The payload was', payload) |
| else: |
| print('Uh oh, this RPC returned', status) |
| |
| status, payload = echo_service.Echo(msg='Goodbye!') |
| |
| print('The device says:', payload.msg) |
| |
| |
| def main(): |
| parser = argparse.ArgumentParser( |
| description=__doc__, |
| formatter_class=argparse.ArgumentDefaultsHelpFormatter) |
| parser.add_argument('--device', |
| '-d', |
| default='/dev/ttyACM0', |
| help='serial device to use') |
| parser.add_argument('--baud', |
| '-b', |
| type=int, |
| default=115200, |
| help='baud rate for the serial device') |
| script(**vars(parser.parse_args())) |
| |
| |
| if __name__ == '__main__': |
| main() |