Connect IoT - Keyboard Wedge Driver#

This driver is intended to handle data read by a device other than a keyboard, such as a magnetic strip or bar code reader or other such scanning device, into keyboard data. With this driver, using cheap readers (barcode, rfid, etc) becomes a reality.

Warning

Very Important: To be able to receive the data sent by the keyboard wedge device, it is necessary to listen to specific event in the operating system. This is also known as keylogger and it is not possible to be used within Microsoft Windows operating systems. For this reason, this driver is only supposed to be executed in Linux operating system, running as administrator privileges (sudo) and with libusb module installed.

Data Types#

These are the supported specific data types:

Name	Description
String	String Value
Boolean	Boolean Value
Integer	Integer value
Decimal	Decimal value
Object	Structured value

Protocol Parameters#

The protocol supports the following parameters:

Name	Type	Possible Values	Default Value	Description
deviceIdentifierType	Enum	VendorAndProductId Path DeviceIndex	VendorAndProductId	Type of identification to use to determine which device the driver will connect to
path	String			Path of the device as known by the operating system. Used when `deviceIdentifierType` is `Path`
vendorId	Integer		0	Id of the vendor of the device to use. Used when `deviceIdentifierType` is `VendorAndProductId`. Use "-1" value to use any vendor id. Expected value to be in decimal format (not hexadecimal).
productId	Integer		0	Id of the product of the device to use. Used when `deviceIdentifierType` is `VendorAndProductId`. Use "-1" value to use any productId id. Expected value to be in decimal format (not hexadecimal).
deviceIndex	Integer		0	Index of the device to use. When `deviceIdentifierType` is `DeviceIndex`, the selected device will be the one that matches the index on all devices. When `deviceIdentifierType` is `VendorAndProductId`, will select the index of the devices among the ones that match the vendor and product id.
parserType	Enum	Raw Readline ByteLength Delimiter InterByteTimeout Ready Regex	ReadLine	Select the parser used to determine when the received data from the device is to be recognized and ready to be processed (check specific section about each of the parsers for more information).
delimiter	string		"\r\n"	Used in parsers `Readline` , `Delimiter`, `Ready`, `RegularExpression`: String delimiter to split incoming text. Simple string substitutions can be used like \r\n\t. If parser is `RegularExpression` you can use regular expressions such as: [\r\n]+
encoding	Enum	ascii utf8 utf16le ucs2 base64 binary hex	ascii	Used in parsers `Readline`, `Regex`: Text encoding for the received data
byteLengthSize	Integer		8	Used in parsers `ByteLength`: Number of bytes to receive before triggering the event
timeoutValue	Integer		1000	Used in parsers `InterByteTimeout`: Period of silence in milliseconds after which data is emitted
maxBufferSize	Integer		65536	Used in parsers: `InterByteTimeout`: Maximum number of bytes after which data will be emitted

Parsers#

Parsers are collection of transform streams to process incoming data. The following parsers are available:

Name	Parameters	Description
Raw		Any data received will be immediately processed.
Readline	delimiter	Data is emitted after the configured newline delimiter is received.
ByteLength	byteLengthSize	Data is emitted right after a specific number of bytes are received.
Delimiter	delimiter	Data is emitted each time a specific sequence is received.
InterByte Timeout	timeoutValue maxBufferSize	Data is emitted after not receiving any bytes for the specified amount of time or if the buffer becomes full.
Ready	delimiter	Data is not emitted until a sequence of `ready` bytes (that match the `delimiter` parameter) before emitting a ready event and emitting data events
Regex	delimiter encoding	A regular expression (delimiter parameter) is used to split the incoming text. The matches are emitted as data to be processed.

Extended Parameters#

As with other protocol drivers, some extra parameters are necessary to provide more context to the behavior expected.

Property#

Name	Type	Possible Values	Default Value	Description
identifierType	Enum	None RegularExpression Token	None	Method used to identify a property. If `None` is used, `identifierValue` will be ignored and all messages will update that property. `Token` type will match `identifierValue` text only on the beginning of the message and `RegularExpression` will match on configured Regular Expression `identifierValue` field.
identifierValue	String			Value of the Property Identifier. Valid on `RegularExpression` (enter a valid regular expression) or `Token` (enter the expected text) `identifierType`.

Event#

Name	Type	Possible Values	Default Value	Description
triggerMode	Enum	AllValues DifferentValues Periodic	AllValues	Determines how and when the data can be emitted as an event. `AllValues`: every time the trigger property value is received `DifferentValues`: every time a different trigger property value is received `Periodic`: On a periodic basis (every `periodicDataInterval`, in milliseconds), disregarding property update cycles or values.
periodicDataInterval	Integer		1000	Number of milliseconds to publish data. Only valid on triggerMode `Periodic`

Event Property#

Name	Type	Possible Values	Default Value	Description
isTrigger	Boolean		true	Trigger the event when the property is received (on event triggerMode `AllValues`), or when the value is changed (on event triggerMode `AllValues` or `DifferentValues`)

Remarks/Behavior#

When an event has more than one property with the isTrigger flag:
- It will be triggered every time any of the properties value changes.
- The value of the other properties will be the one available at the time of the event.
- It is possible to have multiple triggers with the same set values (because they have not changed). If this behavior is not intended, separate into multiple events each one with its own trigger set.
When an event has no property with the isTrigger flag, it will never be triggered (unless event is defined as Periodic)
If you are not sure if libusb is installed, enter the command
```
sudo apt install libusb-1.0-0 libusb-1.0-0-dev
```
According to linux documentation, it is possible to access the device without sudo/root permissions. For more information, check for udev device permissions documentation for your operating system.