PhidgetHelperFunctions.py

import sys
from Phidget22.PhidgetException import *
from Phidget22.ErrorCode import *
from Phidget22.Phidget import *
from Phidget22.Net import *

class NetInfo():    
    def __init__(self):
        self.isRemote = None
        self.serverDiscovery = None
        self.hostname = None
        self.port = None
        self.password = None

class ChannelInfo():
    def __init__(self):
        self.serialNumber = -1
        self.hubPort = -1
        self.isHubPortDevice = 0
        self.channel = -1
        self.netInfo = NetInfo()

class EndProgramSignal(Exception):
    def __init__(self, value):
        self.value = str(value )   

class InputError(Exception):
    """Exception raised for errors in the input.

    Attributes:
        msg  -- explanation of the error
    """

    def __init__(self, msg):
        self.msg = msg

# Returns None if an error occurred, True for 'Y' and False for 'N'  
def ProcessYesNo_Input(default):

    strvar = sys.stdin.readline(100)
    if not strvar:
        raise InputError("Empty Input String")

    strvar = strvar.replace('\r\n', '\n') #sanitize newlines for Python 3.2 and older
    if (strvar[0] == '\n'):
        if (default == -1):
            raise InputError("Empty Input String")
        return default

    if (strvar[0] == 'N' or strvar[0] == 'n'):
        return False

    if (strvar[0] == 'Y' or strvar[0] == 'y'):
        return True

    raise InputError("Invalid Input")

def DisplayError(e):
    sys.stderr.write("Desc: " + e.details + "\n")

def InputSerialNumber(channelInfo):
    print("\nFor all questions, enter the value, or press ENTER to select the [Default]")

    print("\n--------------------------------------")
    print("\n  | Some Phidgets have a unique serial number, printed on a white label on the device.\n"
      "  | For Phidgets and other devices plugged into a VINT Port, use the serial number of the VINT Hub.\n"
      "  | Specify the serial number to ensure you are only opening channels from that specific device.\n"
      "  | Otherwise, use -1 to open a channel on any device.")
    while (True):
        print("\nWhat is the Serial Number? [-1] ")
        strvar = sys.stdin.readline(100)
        if not strvar:
            continue

        strvar = strvar.replace('\r\n', '\n') #sanitize newlines for Python 3.2 and older
        if (strvar[0] == '\n'):
            deviceSerialNumber = -1
            break

        try:
            deviceSerialNumber = int(strvar)
        except ValueError as e:
            continue

        if (deviceSerialNumber >= -1 and deviceSerialNumber != 0):
            break

    channelInfo.deviceSerialNumber = deviceSerialNumber
    return


def InputIsHubPortDevice(channelInfo):
    isHubPortDevice = -1

    while (True):
        print("\nIs this a \"HubPortDevice\"? [y/n] ")
        try:
            isHubPortDevice = ProcessYesNo_Input(-1)
            break
        except InputError as e:
            pass

    channelInfo.isHubPortDevice = isHubPortDevice

    return

def InputVINTProperties(channelInfo, ph):
    canBeHubPortDevice = 0
    pcc = -1
    hubPort = -1
    isVINT = 0

    print("\n--------------------------------------")

    while (True):
        print("\nDo you want to specify the hub port that your device is plugged into?\n"
            "Choose No if your device is not plugged into a VINT Hub. (y/n) ")
        try:
            isVINT = ProcessYesNo_Input(-1)
            break
        except InputError as e:
            pass

    channelInfo.isVINT = isVINT
            
    # Don't ask about the HubPort and the HubPortDevice if it's not a VINT device
    if (not isVINT):
        return

    print("\n--------------------------------------")
    print("\n  | VINT Hubs have numbered ports that can be uniquely addressed.\n"
        "  | The HubPort# is identified by the number above the port it is plugged into.\n"
        "  | Specify the hub port to ensure you are only opening channels from that specific port.\n"
        "  | Otherwise, use -1 to open a channel on any port.")
    while (True):
        print("\nWhat HubPort is the device plugged into? [-1] ")
        strvar = sys.stdin.readline(100)
        if not strvar:
            continue

        strvar = strvar.replace('\r\n', '\n') #sanitize newlines for Python 3.2 and older
        if (strvar[0] == '\n'):
            hubPort = -1
            break

        try:
            hubPort = int(strvar)
        except ValueError as e:
            continue

        if (hubPort >= -1 and hubPort <= 5):
            break

    channelInfo.hubPort = hubPort

    try:
        pcc = ph.getChannelClass()
    except PhidgetException as e:
        sys.stderr.write("Runtime Error -> Getting ChannelClass: \n\t")
        DisplayError(e)
        raise

    if (pcc == ChannelClass.PHIDCHCLASS_VOLTAGEINPUT):
        print("\n--------------------------------------")
        print("\n  | A VoltageInput HubPortDevice uses the VINT Hub's internal channel to measure the voltage on the white wire.\n"
          "  | If the device you are trying to interface returns an analog voltage between 0V-5V, open it as a HubPortDevice.")
        canBeHubPortDevice = 1
    elif (pcc == ChannelClass.PHIDCHCLASS_VOLTAGERATIOINPUT):
        print("\n--------------------------------------")
        print("\n  | A VoltageRatioInput HubPortDevice uses the VINT Hub's internal channel to measure the voltage ratio on the white wire.\n"
          "  | If the device you are trying to interface returns an ratiometric voltage between 0V-5V, open it as a HubPortDevice.")
        canBeHubPortDevice = 1
    elif (pcc == ChannelClass.PHIDCHCLASS_DIGITALINPUT):
        print("\n--------------------------------------")
        print("\n  | A DigitalInput HubPortDevice uses the VINT Hub's internal channel to detect digital changes on the white wire.\n"
          "  | If the device you are trying to interface outputs a 5V digital signal, open it as a HubPortDevice.")
        canBeHubPortDevice = 1
    elif (pcc == ChannelClass.PHIDCHCLASS_DIGITALOUTPUT):
        print("\n--------------------------------------")
        print("\n  | A DigitalOutput HubPortDevice uses the VINT Hub's internal channel to output a 3.3V digital signal on the white wire.\n"
          "  | If the device you are trying to interface accepts a 3.3V digital signal, open it as a HubPortDevice.")
        canBeHubPortDevice = 1

    if (canBeHubPortDevice):
        InputIsHubPortDevice(channelInfo)

    return

def InputChannel(channelInfo):
    isHubPortDevice = 0
    channel = 0

    # Hub port devices only have a single channel, so don't ask for the channel
    if (channelInfo.isHubPortDevice):
        return

    print("\n--------------------------------------")
    print("\n  | Devices with multiple inputs or outputs of the same type will map them to channels.\n"
      "  | The API tab for the device on www.phidgets.com shows the channel breakdown.\n"
      "  | For example, a device with 4 DigitalInputs would use channels [0 - 3]\n"
      "  | A device with 1 VoltageInput would use channel 0")
    while (True):
        print("\nWhat channel# of the device do you want to open? [0] ")
        strvar = sys.stdin.readline(100)
        if not strvar:
            continue

        strvar = strvar.replace('\r\n', '\n') #sanitize newlines for Python 3.2 and older
        if (strvar[0] == '\n'):
            channel = 0
            break

        try:
            channel = int(strvar)
        except ValueError as e:
            continue

        if (channel >= 0):
            break

    channelInfo.channel = channel

    return

def SetupNetwork(channelInfo):
    hostname = ""
    password = ""
    discovery = 0
    isRemote = 0
    port = 0

    print("\n--------------------------------------")
    print("\n  | Devices can either be opened directly, or over the network.\n"
      "  | In order to open over the network, the target system must be running a Phidget Server.")
    while (True):
        print("\nIs this device being opened over the network? [y/N] ")
        try:
            isRemote = ProcessYesNo_Input(0)
            break
        except InputError as e:
            pass

    channelInfo.netInfo.isRemote = isRemote

    # if it's not remote, don't need to ask about the network
    if (not isRemote):
        return

    print("\n--------------------------------------")
    print("\n  | Server discovery enables the dynamic discovery of phidget servers that publish their identity to the network.\n"
          "  | This allows you to open devices over the network without specifying the hostname and port of the server.")
    while (True):
        print("\nDo you want to enable server discovery? [Y/n] ");
        try:
            discovery = ProcessYesNo_Input(1)
            break
        except InputError as e:
            pass

    if (discovery):
        return EnableServerDiscovery(channelInfo)

    print("\n--------------------------------------")
    print("\nPlease provide the following information in order to open the device")

    while (True):
        print("\nWhat is the Hostname (or IP Address) of the server? [localhost] ")
        hostname = sys.stdin.readline(100)
        if not hostname:
            continue

        hostname = hostname.replace('\r\n', '\n') #sanitize newlines for Python 3.2 and older
        if (hostname[0] == '\n'):
            hostname = "localhost"
            break

        # Remove trailing newline
        hostname = hostname.split('\n')[0]
        break

    print("\n--------------------------------------")
    while (True):
        print("\nWhat port is the server on? [5661] ")
        strvar = sys.stdin.readline(100)
        if not strvar:
            continue

        strvar = strvar.replace('\r\n', '\n') #sanitize newlines for Python 3.2 and older
        if (strvar[0] == '\n'):
            port = 5661
            break

        try:
            port = int(strvar)
        except ValueError as e:
            continue

        if (port <= 65535 and port > 0):
            break
    
    print("\n--------------------------------------")
    while (True):
        print("\nWhat is the password of the server? [] ")
        password = sys.stdin.readline(100)
        if not password:
            continue
        # Remove trailing newline
        password = password.replace('\r\n', '\n') #sanitize newlines for Python 3.2 and older

        password = password.split('\n')[0]
        break
    
    print("\n--------------------------------------")

    channelInfo.netInfo.hostname = hostname
    channelInfo.netInfo.port = port
    channelInfo.netInfo.password = password

    return

def PrintOpenErrorMessage(e, ph):
    sys.stderr.write("Runtime Error -> Opening Phidget Channel: \n\t")
    DisplayError(e)
    if(e.code == ErrorCode.EPHIDGET_TIMEOUT):
        sys.stderr.write("\nThis error commonly occurs if your device is not connected as specified, "
                         "or if another program is using the device, such as the Phidget Control Panel.\n")
        if(     ph.getChannelClass() != ChannelClass.PHIDCHCLASS_VOLTAGEINPUT
            and ph.getChannelClass() != ChannelClass.PHIDCHCLASS_VOLTAGERATIOINPUT
            and ph.getChannelClass() != ChannelClass.PHIDCHCLASS_DIGITALINPUT
            and ph.getChannelClass() != ChannelClass.PHIDCHCLASS_DIGITALOUTPUT
        ):
            sys.stderr.write("\nIf you are trying to connect to an analog sensor, you will need to use the "
                             "corresponding VoltageInput or VoltageRatioInput API with the appropriate SensorType.\n")

    
def AskForDeviceParameters(ph):
    channelInfo = ChannelInfo()
    InputSerialNumber(channelInfo)
    InputVINTProperties(channelInfo, ph)    
    InputChannel(channelInfo)    
    SetupNetwork(channelInfo)
    return channelInfo