kirdy-firmware/pykirdy/driver/kirdy_async.py

import socket
import asyncio
import json
import logging
from aenum import StrEnum, NoAlias

class _dt(StrEnum):
    ip_settings = "ip_settings"
    temp_adc_filter = "temp_adc_filter"
    f32 = "data_f32"
    bool = "data_bool"
    none = "None"

class CmdList:
    class device(StrEnum, settings=NoAlias):
        _target = "device_cmd"
        SetIPSettings = _dt.ip_settings
        SetPdFinGain = _dt.f32
        SetPdTransconductance = _dt.f32
        SetActiveReportMode = _dt.bool
        GetStatusReport = _dt.none
        GetSettingsSummary = _dt.none
        Dfu = _dt.none
        SaveFlashSettings = _dt.none
        LoadFlashSettings = _dt.none
        HardReset = _dt.none

    class ld(StrEnum, settings=NoAlias):
        _target = "laser_diode_cmd"
        SetDefaultPowerOn = _dt.bool
        PowerUp = _dt.none
        PowerDown = _dt.none
        LdTermsShort = _dt.none
        LdTermsOpen = _dt.none
        SetI = _dt.f32
        SetISoftLimit = _dt.f32
        SetPdResponsitivity = _dt.f32
        SetPdDarkCurrent = _dt.f32
        SetLdPwrLimit = _dt.f32
        ClearAlarm = _dt.none

    class thermostat(StrEnum, settings=NoAlias):
        _target = "thermostat_cmd"
        SetDefaultPowerOn = _dt.bool,
        PowerUp = _dt.f32,
        PowerDown = _dt.f32,
        SetTecMaxV = _dt.f32,
        SetTecMaxIPos = _dt.f32,
        SetTecMaxINeg = _dt.f32,
        SetTecIOut = _dt.f32, 
        SetTemperatureSetpoint = _dt.f32,
        SetPidEngage = _dt.none,
        SetPidDisEngage = _dt.none,
        SetPidKp = _dt.f32,
        SetPidKi = _dt.f32,
        SetPidKd = _dt.f32,
        SetPidOutMin = _dt.f32,
        SetPidOutMax = _dt.f32,
        ConfigTempAdcFilter = _dt.temp_adc_filter,
        SetTempMonUpperLimit = _dt.f32,
        SetTempMonLowerLimit = _dt.f32,
        ClearAlarm = _dt.none,
        SetShT0 = _dt.f32,
        SetShR0 = _dt.f32,
        SetShBeta = _dt.f32,

class FilterConfig:
    class Sinc5Sinc1With50hz60HzRejection(StrEnum):
        f27sps = "F27SPS"
        f21sps = "F21SPS"
        f20sps = "F20SPS"
        f16sps = "F16SPS"

        def _odr_type(self):
            return "sinc5sinc1postfilter"

        def _filter_type(self):
            return "Sinc5Sinc1With50hz60HzRejection"

    class Sinc5Sinc1(StrEnum):
        f31250_0sps = "F31250_0SPS"
        f15625_0sps = "F15625_0SPS"
        f10417_0sps = "F10417_0SPS"
        f5208_0sps  = "F5208_0SPS" 
        f2597_0sps  = "F2597_0SPS" 
        f1007_0sps  = "F1007_0SPS" 
        f503_8sps   = "F503_8SPS"  
        f381_0sps   = "F381_0SPS"  
        f200_3sps   = "F200_3SPS"  
        f100_2sps   = "F100_2SPS"  
        f59_52sps   = "F59_52SPS"  
        f49_68sps   = "F49_68SPS"  
        f20_01sps   = "F20_01SPS"  
        f16_63sps   = "F16_63SPS"  
        f10_0sps    = "F10_0SPS"   
        f5_0sps     = "F5_0SPS"    
        f2_5sps     = "F2_5SPS"    
        f1_25sps    = "F1_25SPS"   

        def _odr_type(self):
            return "sinc5sinc1odr"
        
        def _filter_type(self):
            return "Sinc5Sinc1"

    class Sinc3(StrEnum):
        f31250_0sps = "F31250_0SPS"
        f15625_0sps = "F15625_0SPS"
        f10417_0sps = "F10417_0SPS"
        f5208_0sps  = "F5208_0SPS" 
        f2597_0sps  = "F2597_0SPS" 
        f1007_0sps  = "F1007_0SPS" 
        f503_8sps   = "F503_8SPS"  
        f381_0sps   = "F381_0SPS"  
        f200_3sps   = "F200_3SPS"  
        f100_2sps   = "F100_2SPS"  
        f59_52sps   = "F59_52SPS"  
        f49_68sps   = "F49_68SPS"  
        f20_01sps   = "F20_01SPS"  
        f16_63sps   = "F16_63SPS"  
        f10_0sps    = "F10_0SPS"   
        f5_0sps     = "F5_0SPS"    
        f2_5sps     = "F2_5SPS"    
        f1_25sps    = "F1_25SPS"   

        def _odr_type(self):
            return "sinc3odr"
        
        def _filter_type(self):
            return "Sinc3"

    class Sinc3WithFineODR():
        def __init__(self, rate):
            assert rate >= 1.907465 and rate <= 31250
            self.rate = float(rate)

        def _odr_type(self):
            return "sinc3fineodr"
        
        def _filter_type(self):
            return "Sinc3WithFineODR"

class InvalidDataType(Exception):
    pass

class InvalidCmd(Exception):
    pass

class NoAckRecv(Exception):
    pass

class StoppedConnecting(Exception):
    pass

class Device:
    def __init__(self, send_cmd_handler, send_raw_cmd_handler, read_response, cmd_lock):
        self._cmd = CmdList.device
        self._send_cmd = send_cmd_handler
        self._send_raw_cmd = send_raw_cmd_handler
        self._read_response = read_response
        self._cmd_lock = cmd_lock

    async def set_ip_settings(self, addr="192.168.1.128", port=1337, prefix_len=24, gateway="192.168.1.1"):
        """
            After calling this fn, the ip settings are immediately saved into flash and will be effective on next reboot.
        """
        try:
            socket.inet_aton(addr)
            socket.inet_aton(gateway)
        except OSError:
            raise InvalidDataType
        
        addr = addr.split(".")
        gateway = gateway.split(".")

        if not(isinstance(port, int) and isinstance(prefix_len, int)):
            raise InvalidDataType
        
        return await self._send_raw_cmd(
            {
                "device_cmd": "SetIPSettings",
                "ip_settings": {
                    "addr": [int(x) for x in addr],
                    "port": port,
                    "prefix_len": prefix_len,
                    "gateway": [int(x) for x in gateway],
                }
            }
        )

    async def set_active_report_mode(self, on):
        """
            Set active report to be on. If it is on, Kirdy will send status report
            to ALL client socket connections according to the temperature polling rate set.
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetActiveReportMode, on)

    async def set_pd_mon_fin_gain(self, gain):
        """
            Configure the photodiode monitor final analog front-end stage gain
                - gain: unitless
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetPdFinGain, gain)

    async def set_pd_mon_transconductance(self, transconductance):
        """
            Configure the photodiode monitor transconductance
                - transconductance: 1/Ohm
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetPdTransconductance, transconductance)

    async def get_status_report(self):
        """
            Get status of all peripherals in a json object

            Example of yielded data::
            {
                'ts': 227657,                   # Relative Timestamp (ms)
                'msg_type': 'Report'            # Indicate it is a 'Report' json object
                'laser': {
                    'pwr_on': False,            # Laser Power is On (True/False)
                    'pwr_excursion': False,     # Was Laser experienced an Overpowered Condition? (True/False)
                    'ld_i_set': 0.0,            # Laser Diode Output Current (A)
                    'pd_i': 2.0000002e-06,      # Internal Photodiode Monitor current (A)
                    'pd_pwr': None,             # Power Readings from Internal Photodiode (W). Return None if pd_mon parameter(s) are not defined.
                    'term_status': 'Is50Ohm'    # Is the Low Frequency Modulation Input's Impedance 50 Ohm? (Is50Ohm/Not50Ohm)
                }, 
                'thermostat': {
                    'pwr_on': False,            # Tec Power is On (True/False)
                    'pid_engaged': False,       # Is Pid_Engaged. If False, it is in Constant Current Mode (True/False)
                    'temp_mon_status': {        # Temperature Monitor:
                        'status': 'Off',            # (To be revised)
                        'over_temp_alarm': False    # Was Laser Diode experienced an Overtemperature condition (True/False)
                    }, 
                    'temperature': 25.03344,   # Temperature Readings (Degree Celsius)
                    'i_set': 0.0,               # Tec Current Set by User/PID Controller(A)
                    'tec_i': 0.0024998188,      # Tec Current Readings (A)
                    'tec_v': -0.00399971        # Tec Voltage Readings (V)
                }
            }
        """
        return await self._send_cmd(self._cmd._target, self._cmd.GetStatusReport, msg_type="Report")

    async def get_settings_summary(self):
        """
            Get the current settings of laser and thermostat in a json object

            {
                'msg_type': 'Settings',             # Indicate it is a 'Settings' json object
                'laser': {
                    'default_pwr_on': False,        # Power On Laser Diode at Startup
                    'ld_drive_current': {           # Laser Diode Output Current(A)
                       'value': 0.0,                    # Value Set
                       'max': 0.3                       # Max Value Settable
                    ,   
                    'ld_drive_current_limit': {     # Laser Diode Software Current Limit(A)
                       'value': 0.3,                    # Value Set
                       'max': 0.3                       # Max Value Settable
                    ,   
                    'pd_mon_params': {              # Laser Diode Software Current Limit(A)
                       'responsitivity': None,          # Value Set
                       'i_dark': 0.0                    # Max Value Settable
                    ,   
                    'ld_pwr_limit': 0.0             # Laser Diode Power Limit(W)
                    'ld_terms_short: False          # Is Laser Diode Terminals short? (True/False)
                }, 
                'thermostat': {
                    'default_pwr_on': True,         # Power on Thermostat at Startup
                    'pid_engaged': True,            # True: PID Control Mode | False Constant Current Mode
                    'temperature_setpoint': 25.0, # Temperature Setpoint (Degree Celsius)
                    'tec_settings': {
                        'i_set': {                  # Current TEC Current Set by PID Controller/User
                            'value': 0.04330516,        # Value Set
                            'max': 1.0                  # Max Value Settable
                        }, 
                        'max_v': {                  # Max Voltage Across Tec Terminals
                            'value': 4.990857,          # Value Set
                            'max': 5.0                  # Max Value Settable
                        }, 
                        'max_i_pos': {              # Max Cooling Current Across Tec Terminals
                            'value': 0.99628574,        # Value Set
                            'max': 1.0                  # Max Value Settable
                        }, 
                        'max_i_neg': {              # Max Heating Current Across Tec Terminals
                            'value': 0.99628574,        # Value Set
                            'max': 1.0                  # Max Value Settable
                        }
                    }, 
                    'pid_params': {                 # PID Controller Parameters
                        'kp': 0.15668282,               # Proportional Gain
                        'ki': 0.0021359625,             # Integral Gain
                        'kd': 0.8292545,                # Derivative Gain
                        'output_min': -1.0,             # Minimum Current Output (A)
                        'output_max': 1.0               # Maximum Current Output (A)
                    }, 
                    'temp_adc_settings': {                                  # Temperature ADC Settings (Please read AD7172-2 Documentation)
                        'filter_type': 'Sinc5Sinc1With50hz60HzRejection',       # Filter Types
                        'sinc5sinc1odr': None,                                  # (Unused)
                        'sinc3odr': None,                                       # (Unused)
                        'sinc5sinc1postfilter': None,                           # (Unused)
                        'sinc3fineodr': None,                                   # (Unused)
                        'rate': 16.67                                           # ADC Sampling Rate (Hz)
                    }, 
                    'temp_mon_settings': {              # Temperature Monitor Settings
                        'upper_limit': 40.0,                # Temperature Upper Limit (Degree Celsius)
                        'lower_limit': 10.0                 # Temperature Lower Limit (Degree Celsius)
                    }, 
                    'thermistor_params': {              # Thermistor Steinhart-Hart equation parameters
                        't0': 25.0,                         # t0: Degree Celsius
                        'r0': 10000.0,                      # r0: Ohm
                        'b': 3900.0                         # b: (unitless)
                    }
                }
            }
        """
        return await self._send_cmd(self._cmd._target, self._cmd.GetSettingsSummary, msg_type="Settings")

    async def dfu(self):
        """
            Issuing this cmd will HARD RESET the device and 
            put Kirdy into Dfu mode for flashing firmware.
        """
        return await self._send_cmd(self._cmd._target, self._cmd.Dfu)

    async def save_current_settings_to_flash(self):
        """
            Save the current laser diode and thermostat configurations into flash.
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SaveFlashSettings)

    async def restore_settings_from_flash(self):
        """
            Restore the laser diode and thermostat settings from flash
        """
        return await self._send_cmd(self._cmd._target, self._cmd.LoadFlashSettings)

    async def hard_reset(self):
        """
            Hard Reset Kirdy. The socket connection will be closed by Kirdy. 
            Laser diode power and Tec power will be turned off.
            Kirdy will send out a json({'msg_type': 'HardReset'}) to all sockets indicating. The device is being reset.
        """
        response = await self._send_cmd(self._cmd._target, self._cmd.HardReset)
        if response is not None:
            if response["msg_type"] == "Acknowledge":
                # Delay for a second to wait for the hard reset message being sent out on Kirdy
                await asyncio.sleep(1.0)
        return response 

class Laser:
    def __init__(self, send_cmd_handler, cmd_lock):
        self._cmd = CmdList.ld
        self._send_cmd = send_cmd_handler
        self._cmd_lock = cmd_lock

    async def set_power_on(self, on):
        """
            Power Up or Power Down laser diode. Powering up the Laser Diode resets the pwr_excursion status
                - on (True/False)
        """
        if on:
            return await self._send_cmd(self._cmd._target, self._cmd.PowerUp, None)
        else:
            return await self._send_cmd(self._cmd._target, self._cmd.PowerDown, None)

    async def set_default_pwr_on(self, on):
        """
            Set whether laser diode is powered up at Startup
                - on (True/False)
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetDefaultPowerOn, on)
    
    async def set_ld_terms_short(self, short):
        """
            Open/Short laser diode terminals.
                - on (True/False)
        """
        if short:
            return await self._send_cmd(self._cmd._target, self._cmd.LdTermsShort, None)
        else:
            return await self._send_cmd(self._cmd._target, self._cmd.LdTermsOpen, None)

    async def set_i(self, i):
        """
            Set laser diode output current: Max(0, Min(i_set, i_soft_limit))
                - i: A  
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetI, i)

    async def set_i_soft_limit(self, i_limit):
        """
            Set laser diode software output current limit
                - i_limit: A
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetISoftLimit, i_limit)
    
    async def set_pd_mon_responsitivity(self, responsitivity):
        """
            Configure the photodiode monitor responsitivity parameter
                - responsitivity: A/W
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetPdResponsitivity, responsitivity)

    async def set_pd_mon_dark_current(self, dark_current):
        """
            Configure the photodiode monitor responsitivity parameter
                - dark_current: A/W
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetPdDarkCurrent, dark_current)

    async def set_ld_pwr_limit(self, pwr_limit):
        """
            Set power limit for the power excursion monitor
            If the calculated power with the params of pd_mon > pwr_limit,
            overpower protection is triggered.
                - pwr_limit: W 
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetLdPwrLimit, pwr_limit)

    async def clear_alarm(self):
        """
            Clear the power excursion monitor alarm 
        """
        return await self._send_cmd(self._cmd._target, self._cmd.ClearAlarm)

class Thermostat:
    def __init__(self, send_cmd_handler, send_raw_cmd_handler, cmd_lock):
        self._cmd = CmdList.thermostat
        self._send_cmd = send_cmd_handler
        self._send_raw_cmd = send_raw_cmd_handler
        self._cmd_lock = cmd_lock
    async def set_power_on(self, on):
        """
            Power up or power down thermostat
                - Powering up the thermostat resets the pwr_excursion status
        """
        if on:
            return await self._send_cmd(self._cmd._target, self._cmd.PowerUp, None)
        else:
            return await self._send_cmd(self._cmd._target, self._cmd.PowerDown, None)

    async def set_default_pwr_on(self, on):
        """
            Set whether thermostat is powered up at Startup
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetDefaultPowerOn, on)

    async def set_tec_max_v(self, max_v):
        """
            Set Tec Maximum Voltage Across the TEC Terminals
                - max_v: V
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetTecMaxV, max_v)

    async def set_tec_max_cooling_i(self, max_i_pos):
        """
            Set Tec maximum cooling current (Settable Range: 0.0 - 1.0)
                - max_i_pos: A
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetTecMaxIPos, max_i_pos)

    async def set_tec_max_heating_i(self, max_i_neg):
        """
            Set Tec maximum heating current (Settable Range: 0.0 - 1.0)
                - max_i_neg: A
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetTecMaxINeg, max_i_neg)

    async def set_tec_i_out(self, i_out):
        """
            Set Tec Output Current
            This cmd is only effective in constant current control mode 
            or your newly set value will be overwritten by PID Controller Output
                - i_out: A
        """
        if isinstance(i_out, float):
            return await self._send_raw_cmd({"tec_set_i": i_out})
        elif isinstance(i_out, int):
            return await self._send_raw_cmd({"tec_set_i": float(i_out)})
        else:
            raise InvalidDataType

    async def set_constant_current_control_mode(self):
        """
            Disable PID Controller and output current can be controlled with set_tec_i_out() cmd.
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetPidDisEngage, None)

    async def set_temperature_setpoint(self, temperature):
        """
            Set Temperature Setpoint for PID Controller. This parameter is not active in constant current control mode
                - temperature: Degree Celsius
        """

        return await self._send_cmd(self._cmd._target, self._cmd.SetTemperatureSetpoint, temperature)

    async def set_pid_control_mode(self):
        """
            Enable PID Controller. Its PID Update Interval is controlled by the Temperature ADC polling rate.
            Please refer to config_temp_adc_filter for the possible polling rate options
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetPidEngage, None)

    async def set_pid_kp(self, kp):
        """
            Set Kp parameter for PID Controller
                kp: (unitless) 
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetPidKp, kp)

    async def set_pid_ki(self, ki):
        """
            Set Ki parameter for PID Controller
                ki: (unitless) 
        """
        await self._send_cmd(self._cmd._target, self._cmd.SetPidKi, ki)

    async def set_pid_kd(self, kd):
        """
            Set Kd parameter for PID Controller
                kd: (unitless) 
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetPidKd, kd)

    async def set_pid_output_max(self, out_max):
        """
            Set max output limit at the PID Output
                - out_max: A
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetPidOutMax, out_max)
    
    async def set_pid_output_min(self, out_min):
        """
            Set min output limit at the PID Output
                - out_min: A
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetPidOutMin, out_min)
    
    async def set_temp_mon_upper_limit(self, upper_limit):
        """
            Set Temperature Monitor Upper Limit Threshold. Exceeding the limit for too long
            will force the TEC Controller, PID Controller and Laser Diode Power to Shutdown
                - upper_limit: Degree Celsius
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetTempMonUpperLimit, upper_limit)

    async def set_temp_mon_lower_limit(self, lower_limit):
        """
            Set Temperature Monitor Lower Limit Threshold. Exceeding the limit for too long
            will force the TEC Controller, PID Controller and Laser Diode Power to Shutdown
                - lower_limit: Degree Celsius
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetTempMonLowerLimit, lower_limit)

    async def clear_alarm(self):
        """
            Clear the temperature monitor alarm
        """
        return await self._send_cmd(self._cmd._target, self._cmd.ClearAlarm)

    async def set_sh_t0(self, t0):
        """
            Set t0 Steinhart-Hart parameter for the laser diode NTC 
                - t0: Degree Celsius
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetShT0, t0)

    async def set_sh_r0(self, r0):
        """
            Set r0 Steinhart-Hart parameter for the laser diode NTC
                - r0: Ohm
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetShR0, r0)

    async def set_sh_beta(self, beta):
        """
            Set beta Steinhart-Hart parameter for the laser diode NTC 
                - beta: (unitless)
        """
        return await self._send_cmd(self._cmd._target, self._cmd.SetShBeta, beta)
    
    async def config_temp_adc_filter(self, filter_config):
        """
            Configure the temperature adc filter type and sampling rate. 
            Please refer to AD7172 datasheet for the usage of various types of filter.
            The actual temperature polling rate is bottlenecked by the processing speed of the MCU and
            performs differently under different kinds of workload. Please verify the polling rate with
            the timestamp.
        """
        cmd = {}
        cmd[self._cmd._target] = self._cmd.ConfigTempAdcFilter.name
        if hasattr(filter_config, 'rate'):
            cmd[self._cmd.ConfigTempAdcFilter] = { 
                "filter_type": filter_config._filter_type(),
                filter_config._odr_type(): filter_config.rate,
            }
        else:
            cmd[self._cmd.ConfigTempAdcFilter] = { 
                "filter_type": filter_config._filter_type(),
                filter_config._odr_type(): filter_config,
            }

        return await self._send_raw_cmd(cmd)

class Kirdy:
    def __init__(self):
        self._reader = None
        self._writer = None
        self._connecting_task = None
        self._cmd_lock = asyncio.Lock()
        self._report_mode_on = False
        self.timeout = None
        self.device = Device(self._send_cmd_handler, self._send_raw_cmd_handler, self._read_response, self._cmd_lock)
        self.laser = Laser(self._send_cmd_handler, self._cmd_lock)
        self.thermostat = Thermostat(self._send_cmd_handler, self._send_raw_cmd_handler, self._cmd_lock)
        
    async def start_session(self, host='192.168.1.128', port=1337, timeout=None):
        self._connecting_task = asyncio.create_task(
            asyncio.wait_for(asyncio.open_connection(host, port), timeout)
        )
        self.timeout = timeout
        try:
            self._reader, self._writer = await self._connecting_task
            writer_sock = self._writer.get_extra_info("socket")
            writer_sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)

        except asyncio.CancelledError:
            raise StoppedConnecting
        finally:
            self._connecting_task = None

    def connecting(self):
        """Returns True if client is connecting"""
        return self._connecting_task is not None

    def connected(self):
        """Returns True if client is connected"""
        return self._writer is not None

    async def end_session(self):
        """End session to Kirdy if connected, cancel connection if connecting"""
        if self._connecting_task is not None:
            self._connecting_task.cancel()

        if self._writer is None:
            return

        # Reader needn't be closed
        self._writer.close()
        try:
            await self._writer.wait_closed()
        except ConnectionResetError:
            # In Hard Reset/DFU cmd, Kirdy may close its socket first
            pass
        self._reader = None
        self._writer = None

    async def _read_response(self, buffer_size=16384, report=False):
        """
            Decode newline delimited Json objects and return the latest json received inside the buffer.
                - buffer_size: Integer
        """
        try: 
            raw_response = await asyncio.wait_for(self._reader.read(buffer_size), self.timeout)

            response = raw_response.decode('utf-8', errors='ignore').split("\n")
            items = []
            for item in reversed(response):
                try:
                    items.append(json.loads(item))
                except json.decoder.JSONDecodeError as e:
                    pass
            if len(items) > 0 :
                if report:
                    return items[0]
                else:    
                    return items
            else:
                return { "msg_type": "EmptyResponse"}
        except TimeoutError:
            return { "msg_type": "RecvTimeout"}

    async def _send_raw_cmd_handler(self, cmd, lock=True, msg_type="Acknowledge"):
        if lock:
            async with self._cmd_lock:
                return await asyncio.shield(self._send_raw_cmd(cmd, msg_type))
        else:
            return await asyncio.shield(self._send_raw_cmd(cmd, msg_type))
    
    # If the cmd involves a cmd specific data type, 
    #   checking is done separately within the functions being called
    async def _send_raw_cmd(self, cmd, msg_type):
        retry = 0
        while retry < 10:
            try:
                self._writer.write(bytes(json.dumps(cmd), "UTF-8"))
                await self._writer.drain()
                responses = await self._read_response()
                for response in responses:
                    if response["msg_type"] == msg_type:
                        return response
                    if response["msg_type"] == "InvalidCmd":
                        raise InvalidCmd
            except asyncio.exceptions.CancelledError:
                return None
            except Exception as e:
                retry += 1
                logging.error(f"_send_raw_cmd Exception: {e}")
                await asyncio.sleep(0.1)
        raise NoAckRecv

    async def _send_cmd_handler(self, target, cmd, data=None, msg_type="Acknowledge", lock=True):
        if lock:
            async with self._cmd_lock:
                return await asyncio.shield(self._send_cmd(target, cmd, data, msg_type))
        else:
            return await asyncio.shield(self._send_cmd(target, cmd, data, msg_type))

    async def _send_cmd(self, target, cmd, data, msg_type):
        cmd_dict = {}
        cmd_dict[target] = cmd.name

        if cmd == _dt.f32:
            if isinstance(data, float):
                cmd_dict[cmd] = data
            elif isinstance(data, int):
                cmd_dict[cmd] = float(data)
        elif cmd == _dt.bool:
            if isinstance(data, bool):
                cmd_dict[cmd] = data
            else:
                raise InvalidDataType
        elif cmd == "None":
            pass

        retry = 0
        while retry < 10:
            try:
                self._writer.write(bytes(json.dumps(cmd_dict), "UTF-8"))
                await self._writer.drain()
                responses = await self._read_response()
                for response in responses:
                    if response["msg_type"] == msg_type:
                        return response
                retry += 1
                
                await asyncio.sleep(0.1)
            except asyncio.exceptions.CancelledError:
                return None
        raise NoAckRecv

    async def report_mode(self, report_interval = 0.0, buffer_size=16384):
        """
            Start reporting device status in json object. Optional report_interval can be added to discard unwanted samples.
            Only the latest status report received within the buffer is returned. 
                - polling interval: float/int (unit: seconds)
                - buffer_size: int
        """
        await self.device.set_active_report_mode(True)
        self._report_mode_on = True

        while self._report_mode_on:
            await asyncio.sleep(report_interval)
            async with self._cmd_lock:
                yield await self._read_response(buffer_size, report=True)

        await self.device.set_active_report_mode(False)

    def stop_report_mode(self):
        self._report_mode_on = False