---
alias: user-guide-driver-keyboardwedge
tags:
- connect iot
description: "This driver facilitates data capture from scanning devices like barcodes, enabling keyboard data processing primarily on Linux systems"
---

# 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<br>Path<br>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<br>Readline<br>ByteLength<br>Delimiter<br>InterByteTimeout<br>Ready<br>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<br>utf8<br>utf16le<br>ucs2<br>base64<br>binary<br>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<br>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<br>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<br>RegularExpression<br>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<br>DifferentValues<br>Periodic | AllValues | Determines how and when the data can be emitted as an event.<br>`AllValues`: every time the trigger property value is received<br>`DifferentValues`: every time a different trigger property value is received<br>`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

    ```sh
    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.