how can I check if sensor is in sleep mode?

[tikky]

Hello,

how can I check if sensor is in sleep mode?

I am trying

sensor.sleep(sleep=True)
print (sensor.sleep(read=True))
sensor.sleep()
print (sensor.sleep(read=True))

but this won't work as expected.
I am getting two times

None
None

[mpnesta]

to check serial port you can use "isOpen()", serial.isOpen()
try "sensor.ser.isOpen()"

[tikky]

sensor.ser.isOpen() always give me TRUE

I am not sure if you have read my question properly.
I did not want to check if serial port is open, but I'am interested to know if SDS011 is in "sleep mode" - is fan off or on?

Hope we can find a solution.

[mpnesta]

I'm not an expert and I don't use this library but from the sensor documentation and this code,

sensor.sleep(sleep=True)

is correct to read the status, but the function don't return nothing, so you must modify it how dows "def query(self)" function or create a new function

 def sleep(self, read=False, sleep=True):
        """Sleep/Wake up the sensor.
        @param sleep: Whether the device should sleep or work.
        @type sleep: bool
        """
        cmd = self.cmd_begin()
        cmd += (self.SLEEP_CMD
                + (self.READ if read else self.WRITE)
                + (self.SLEEP if sleep else self.WORK)
                + b"\x00" * 10)
        cmd = self._finish_cmd(cmd)
        self._execute(cmd)
    ---------  modify ------
        raw = self._get_reply()
        if raw is None:
            return None
        data = struct.unpack('B', raw[4:5])    #1=work, 0=sleep

0 sleep and 1 run

UPDATE 12/11/2019 20:46
I tested it in my code and it seems to work, but it is necessary to manage the situation when the fan is off (sleep = 1), in this case the documentation says:

"4. Set sleep and work .... The setting is not effective after power off 【stay work state after power on】 "

so it's important to set a timeout when you instantiate the " Serial " object
self.ser = serial.Serial (port = serial_port, baudrate = baudrate, timeout = timeout)
because if the sensor is sleeping and you launch the reading of the device, the program block