# Tibbo WebSerial Library
### Introduction
The [Tibbo Web232](https://tibbo.com/store/webserial/web232.html) and [Tibbo Web485](https://tibbo.com/store/webserial/web485.html) boards work as standard USB-to-RS232/USB-to-RS485 adaptors, but with WebUSB support.
This JavaScript API allows web-based applications to access USB devices. WebUSB is supported by the Google Chrome browser and is also included in the Chromium open-source browser builds. If you are using Chrome (or a Chromium-based) browser, your web pages will be able to access an RS232 device connected to a Web232 board or an RS485 device connected to a Web485 board.
### Installation
To use this library, the following lines should be included in the `` section of the HTML file.
```html
```
### Initialization
#### Instantiating Serial Object
In order to use this library, it is necessary to first instantiate the TibboWebSerial.Serial object, passing the correct device as a parameter. This is best done through an *onclick* event. The code below shows the most basic example of how to do this:
```html
```
When the button is clicked, a list of available USB devices will be displayed. The device called "Web232" or "Web485" should be selected. An instance of `TibboWebSerial.Serial` called `serial` has now been created!
#### Declaring Callbacks
There are a number of callbacks functions available, each one is detailed here. To use a callback, it must first be declared. A good time to do this would be just after instantiating the serial object. For example, to generate a callback when a successful connection is made to the device, the `connectOK` callback could be used. First, the callback should be declared after the serial object is instantiated using the following line of code:
```javascript
serial.connectOK = this.onConnectOK;
```
Next, the body of the callback must be added. In order to display an alert when the connection is ok, the following function could be added:
```javascript
function onConnectOK() {
alert("Successfully connected to device");
}
```
Thus, the previous example becomes:
```html
```
### Functions
| Function | Parameter | Description | Return Value |
| --------------------------- | ------------------------------------- | :----------------------------------------------------------- | ------------------------------------- |
| `setBaud(Baud)` | Number | Sets baud to value passed in parameter Tested on all of the standard bauds between 110 and 921600. | - |
| setFlowControl(Flowcontrol) | "OFF", "CTS_RTS" "XON_XOFF" | Sets the flow control according to value passed passed as parameter | - |
| write(data) | String | Sends data passed as parameter through the serial port | - |
| getFlowControl() | - | Returns the currently set flow control | "OFF", "CTS_RTS" "XON_XOFF" |
| toggleLINE(Line) | LINE_STATES.RTS LINE_STATES.RTS | Toggles the line that is passed as a parameter. | - |
| disconnect() | - | Disconnects from the Web232/Web485 board | |
### Callbacks
| Callback | Description |
| ---------------------------------------------- | ------------------------------------------------------------ |
| modemStateChanged(DTR, RTS, CTS, DSR, RI, DCD) | Triggered when modem state changes Arguments provide the updated state of each of the 6 lines |
| flowControlChanged(flowControl) | Triggered when flow control changes Argument provides the updated flow control value |
| baudChangeOK(baud) | Triggered when baud successfully changes Argument provides the updated baud value |
| onSerDataArrival(data) | Triggered when data arrives from the serial port Argument provides the received data |
| onSerDataSent(data) | Triggered when data is sent from the serial port Argument provides the sent data |
| onConnectOK() | Triggered when a connection to the Web232/Web485 board is successfully established |
| onDisconnectOK() | Triggered when a connection to the Web232/Web485 board is successfully terminated |
| onConnectionError() | Triggered when a connection to the Web232/Web485 board is unexpectedly terminated, for example when the cable is unplugged |
| onConnectFail() | Triggered when a connection to the Web232/Web485 board is not able to be established, for example if a connection to an incompatible device is attempted. |