Custom drivers

stepper/
  lager_driver.json   # 清单文件
  driver.py           # class Driver(CustomDriver)
  helpers.py          # 可选；driver.py 可以按名称导入

{
  "type": "stepper",
  "version": "1.0.0",
  "lager_api": 1,
  "description": "Stepper rig controlled over a UART net",
  "timeout_s": 30,
  "params": {
    "uart_net": {"type": "net", "role": "uart", "required": true,
                 "help": "UART net wired to the controller"},
    "baudrate": {"type": "int", "default": 115200, "help": "Serial baud rate"}
  },
  "actions": {
    "position": {"help": "Query the current position"},
    "home": {"help": "Return to the home position"},
    "jog": {
      "help": "Move forward for N seconds, then return home",
      "args": {
        "seconds": {"type": "float", "min": 0.1, "max": 30, "required": true}
      }
    }
  }
}

from lager.drivers import CustomDriver, action


class Driver(CustomDriver):
    def setup(self):
        # base_net() returns the built-in net that a "net" param names
        self.port = self.base_net("uart_net").connect(
            baudrate=self.params["baudrate"], timeout=2)

    @action
    def position(self):
        self.port.write(b"?\r")
        return {"message": "position read", "position": int(self.port.readline())}

    @action
    def jog(self, seconds):
        self.port.write(b"1\r")
        ...
        return {"message": "jogged %s s and returned home" % seconds}

    def teardown(self):
        self.port.close()

from lager.drivers import open_driver

with open_driver("RIG_1") as rig:
    rig.home()
    rig.jog(seconds=3)

lager drivers install ./stepper --box my-lager-box
lager nets add-custom RIG_1 stepper --param uart_net=UART_1 --box my-lager-box
lager stepper RIG_1 jog --seconds 3 --box my-lager-box