JavaScript - RS232 Bricklet 2.0

This is the description of the JavaScript API bindings for the RS232 Bricklet 2.0. General information and technical specifications for the RS232 Bricklet 2.0 are summarized in its hardware description.

An installation guide for the JavaScript API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Loopback (Node.js)

Download (ExampleLoopback.js)

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var Tinkerforge = require('tinkerforge');

// For this example connect the RX pin to the TX pin on the same Bricklet

var HOST = 'localhost';
var PORT = 4223;
var UID = 'XYZ'; // Change XYZ to the UID of your RS232 Bricklet 2.0

var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var rs232 = new Tinkerforge.BrickletRS232V2(UID, ipcon); // Create device object

ipcon.connect(HOST, PORT,
    function (error) {
        console.log('Error: ' + error);
    }
); // Connect to brickd
// Don't use device before ipcon is connected

ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
    function (connectReason) {
        // Enable read callback
        rs232.enableReadCallback();

        // Write "test" string
        rs232.write('test'.split(''));
    }
);

// Register read callback
rs232.on(Tinkerforge.BrickletRS232V2.CALLBACK_READ,
    // Callback function for read callback
    function (message) {
        // Assume that the message consists of ASCII characters and
        // convert it from an array of chars to a string
        console.log('Message: "' + message.join('') + '"');
    }
);

console.log('Press key to exit');
process.stdin.on('data',
    function (data) {
        ipcon.disconnect();
        process.exit(0);
    }
);

Loopback (HTML)

Download (ExampleLoopback.html), Test (ExampleLoopback.html)

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<!DOCTYPE html>

<!-- For this example connect the RX pin to the TX pin on the same Bricklet -->

<html>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <head>
        <title>Tinkerforge | JavaScript Example</title>
    </head>
    <body>
        <div style="text-align:center;">
            <h1>RS232 Bricklet 2.0 Loopback Example</h1>
            <p>
                <input value="localhost" id="host" type="text" size="20">:
                <input value="4280" id="port" type="text" size="5">,
                <input value="uid" id="uid" type="text" size="5">
                <input value="Start Example" id="start" type="button" onclick="startExample();">
            </p>
            <p>
                <textarea readonly id="text" cols="80" rows="24" style="resize:none;"
                          >Press "Start Example" to begin ...</textarea>
            </p>
        </div>
        <script src="./Tinkerforge.js" type='text/javascript'></script>
        <script type='text/javascript'>
            var ipcon;
            var textArea = document.getElementById("text");
            function startExample() {
                textArea.value = "";
                var HOST = document.getElementById("host").value;
                var PORT = parseInt(document.getElementById("port").value);
                var UID = document.getElementById("uid").value;
                if(ipcon !== undefined) {
                    ipcon.disconnect();
                }
                ipcon = new Tinkerforge.IPConnection(); // Create IP connection
                var rs232 = new Tinkerforge.BrickletRS232V2(UID, ipcon); // Create device object
                ipcon.connect(HOST, PORT,
                    function(error) {
                        textArea.value += 'Error: ' + error + '\n';
                    }
                ); // Connect to brickd
                // Don't use device before ipcon is connected

                ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
                    function (connectReason) {
                        // Enable read callback
                        rs232.enableReadCallback();

                        // Write "test" string
                        rs232.write('test'.split(''));
                    }
                );

                // Register read callback
                rs232.on(Tinkerforge.BrickletRS232V2.CALLBACK_READ,
                    // Callback function for read callback
                    function (message) {
                        // Assume that the message consists of ASCII characters and
                        // convert it from an array of chars to a string
                        textArea.value += 'Message: "' + message.join('') + '"\n';
                        textArea.scrollTop = textArea.scrollHeight;
                    }
                );
            }
        </script>
    </body>
</html>

API

Generally, every method of the JavaScript bindings can take two optional parameters, returnCallback and errorCallback. These are two user defined callback functions. The returnCallback is called with the return values as parameters, if the method returns something. The errorCallback is called with an error code in case of an error. The error code can be one of the following values:

  • IPConnection.ERROR_ALREADY_CONNECTED = 11
  • IPConnection.ERROR_NOT_CONNECTED = 12
  • IPConnection.ERROR_CONNECT_FAILED = 13
  • IPConnection.ERROR_INVALID_FUNCTION_ID = 21
  • IPConnection.ERROR_TIMEOUT = 31
  • IPConnection.ERROR_INVALID_PARAMETER = 41
  • IPConnection.ERROR_FUNCTION_NOT_SUPPORTED = 42
  • IPConnection.ERROR_UNKNOWN_ERROR = 43

The namespace for the JavaScript bindings is Tinkerforge.*.

Basic Functions

new BrickletRS232V2(uid, ipcon)
Parameters:
  • uid -- string
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

var rs232V2 = new BrickletRS232V2("YOUR_DEVICE_UID", ipcon);

This object can then be used after the IP Connection is connected (see examples above).

BrickletRS232V2.writeLowLevel(messageLength, messageChunkOffset, messageChunkData[, returnCallback][, errorCallback])
Parameters:
  • messageLength -- int
  • messageChunkOffset -- int
  • messageChunkData -- [char, char, ..57x.., char]
Callback:
  • messageChunkWritten -- int

Writes characters to the RS232 interface. The characters can be binary data, ASCII or similar is not necessary.

The return value is the number of characters that were written.

See setConfiguration() for configuration possibilities regarding baud rate, parity and so on.

BrickletRS232V2.readLowLevel(length[, returnCallback][, errorCallback])
Parameters:
  • length -- int
Callback:
  • messageLength -- int
  • messageChunkOffset -- int
  • messageChunkData -- [char, char, ..57x.., char]

Returns up to length characters from receive buffer.

Instead of polling with this function, you can also use callbacks. But note that this function will return available data only when the read callback is disabled. See enableReadCallback() and CALLBACK_READ callback.

BrickletRS232V2.setConfiguration(baudrate, parity, stopbits, wordlength, flowcontrol[, returnCallback][, errorCallback])
Parameters:
  • baudrate -- int
  • parity -- int
  • stopbits -- int
  • wordlength -- int
  • flowcontrol -- int
Callback:

undefined

Sets the configuration for the RS232 communication. Available options:

  • Baud rate between 100 and 2000000 baud.
  • Parity of none, odd or even.
  • Stop bits can be 1 or 2.
  • Word length of 5 to 8.
  • Flow control can be off, software or hardware.

The default is: 115200 baud, parity none, 1 stop bit, word length 8.

The following constants are available for this function:

  • BrickletRS232V2.PARITY_NONE = 0
  • BrickletRS232V2.PARITY_ODD = 1
  • BrickletRS232V2.PARITY_EVEN = 2
  • BrickletRS232V2.STOPBITS_1 = 1
  • BrickletRS232V2.STOPBITS_2 = 2
  • BrickletRS232V2.WORDLENGTH_5 = 5
  • BrickletRS232V2.WORDLENGTH_6 = 6
  • BrickletRS232V2.WORDLENGTH_7 = 7
  • BrickletRS232V2.WORDLENGTH_8 = 8
  • BrickletRS232V2.FLOWCONTROL_OFF = 0
  • BrickletRS232V2.FLOWCONTROL_SOFTWARE = 1
  • BrickletRS232V2.FLOWCONTROL_HARDWARE = 2
BrickletRS232V2.getConfiguration([returnCallback][, errorCallback])
Callback:
  • baudrate -- int
  • parity -- int
  • stopbits -- int
  • wordlength -- int
  • flowcontrol -- int

Returns the configuration as set by setConfiguration().

The following constants are available for this function:

  • BrickletRS232V2.PARITY_NONE = 0
  • BrickletRS232V2.PARITY_ODD = 1
  • BrickletRS232V2.PARITY_EVEN = 2
  • BrickletRS232V2.STOPBITS_1 = 1
  • BrickletRS232V2.STOPBITS_2 = 2
  • BrickletRS232V2.WORDLENGTH_5 = 5
  • BrickletRS232V2.WORDLENGTH_6 = 6
  • BrickletRS232V2.WORDLENGTH_7 = 7
  • BrickletRS232V2.WORDLENGTH_8 = 8
  • BrickletRS232V2.FLOWCONTROL_OFF = 0
  • BrickletRS232V2.FLOWCONTROL_SOFTWARE = 1
  • BrickletRS232V2.FLOWCONTROL_HARDWARE = 2

Advanced Functions

BrickletRS232V2.setBufferConfig(sendBufferSize, receiveBufferSize[, returnCallback][, errorCallback])
Parameters:
  • sendBufferSize -- int
  • receiveBufferSize -- int
Callback:

undefined

Sets the send and receive buffer size in byte. In total the buffers have to be 10240 byte (10kb) in size, the minimum buffer size is 1024 byte (1kb) for each.

The current buffer content is lost if this function is called.

The send buffer holds data that is given by write() and can not be written yet. The receive buffer holds data that is received through RS232 but could not yet be send to the user, either by read() or through CALLBACK_READ callback.

The default configuration is 5120 byte (5kb) per buffer.

BrickletRS232V2.getBufferConfig([returnCallback][, errorCallback])
Callback:
  • sendBufferSize -- int
  • receiveBufferSize -- int

Returns the buffer configuration as set by setBufferConfig().

BrickletRS232V2.getBufferStatus([returnCallback][, errorCallback])
Callback:
  • sendBufferUsed -- int
  • receiveBufferUsed -- int

Returns the currently used bytes for the send and received buffer.

See setBufferConfig() for buffer size configuration.

BrickletRS232V2.getErrorCount([returnCallback][, errorCallback])
Callback:
  • errorCountOverrun -- int
  • errorCountParity -- int

Returns the current number of overrun and parity errors.

BrickletRS232V2.getAPIVersion()
Return type:[int, int, int]

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

BrickletRS232V2.getResponseExpected(functionId[, errorCallback])
Parameters:
  • functionId -- int
Return type:

boolean

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by setResponseExpected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See setResponseExpected() for the list of function ID constants available for this function.

BrickletRS232V2.setResponseExpected(functionId, responseExpected[, errorCallback])
Parameters:
  • functionId -- int
  • responseExpected -- boolean

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

  • BrickletRS232V2.FUNCTION_ENABLE_READ_CALLBACK = 3
  • BrickletRS232V2.FUNCTION_DISABLE_READ_CALLBACK = 4
  • BrickletRS232V2.FUNCTION_SET_CONFIGURATION = 6
  • BrickletRS232V2.FUNCTION_SET_BUFFER_CONFIG = 8
  • BrickletRS232V2.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletRS232V2.FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletRS232V2.FUNCTION_RESET = 243
  • BrickletRS232V2.FUNCTION_WRITE_UID = 248
BrickletRS232V2.setResponseExpectedAll(responseExpected)
Parameters:
  • responseExpected -- boolean

Changes the response expected flag for all setter and callback configuration functions of this device at once.

BrickletRS232V2.getSPITFPErrorCount([returnCallback][, errorCallback])
Callback:
  • errorCountAckChecksum -- int
  • errorCountMessageChecksum -- int
  • errorCountFrame -- int
  • errorCountOverflow -- int

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

BrickletRS232V2.setBootloaderMode(mode[, returnCallback][, errorCallback])
Parameters:
  • mode -- int
Callback:
  • status -- int

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

  • BrickletRS232V2.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletRS232V2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BrickletRS232V2.BOOTLOADER_STATUS_OK = 0
  • BrickletRS232V2.BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletRS232V2.BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletRS232V2.BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletRS232V2.BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletRS232V2.BOOTLOADER_STATUS_CRC_MISMATCH = 5
BrickletRS232V2.getBootloaderMode([returnCallback][, errorCallback])
Callback:
  • mode -- int

Returns the current bootloader mode, see setBootloaderMode().

The following constants are available for this function:

  • BrickletRS232V2.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletRS232V2.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletRS232V2.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickletRS232V2.setWriteFirmwarePointer(pointer[, returnCallback][, errorCallback])
Parameters:
  • pointer -- int
Callback:

undefined

Sets the firmware pointer for writeFirmware(). The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

BrickletRS232V2.writeFirmware(data[, returnCallback][, errorCallback])
Parameters:
  • data -- [int, int, ..61x.., int]
Callback:
  • status -- int

Writes 64 Bytes of firmware at the position as written by setWriteFirmwarePointer() before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

BrickletRS232V2.setStatusLEDConfig(config[, returnCallback][, errorCallback])
Parameters:
  • config -- int
Callback:

undefined

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

  • BrickletRS232V2.STATUS_LED_CONFIG_OFF = 0
  • BrickletRS232V2.STATUS_LED_CONFIG_ON = 1
  • BrickletRS232V2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletRS232V2.STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletRS232V2.getStatusLEDConfig([returnCallback][, errorCallback])
Callback:
  • config -- int

Returns the configuration as set by setStatusLEDConfig()

The following constants are available for this function:

  • BrickletRS232V2.STATUS_LED_CONFIG_OFF = 0
  • BrickletRS232V2.STATUS_LED_CONFIG_ON = 1
  • BrickletRS232V2.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletRS232V2.STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletRS232V2.getChipTemperature([returnCallback][, errorCallback])
Callback:
  • temperature -- int

Returns the temperature in °C as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

BrickletRS232V2.reset([returnCallback][, errorCallback])
Callback:undefined

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

BrickletRS232V2.writeUID(uid[, returnCallback][, errorCallback])
Parameters:
  • uid -- int
Callback:

undefined

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

BrickletRS232V2.readUID([returnCallback][, errorCallback])
Callback:
  • uid -- int

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

BrickletRS232V2.getIdentity([returnCallback][, errorCallback])
Callback:
  • uid -- string
  • connectedUid -- string
  • position -- char
  • hardwareVersion -- [int, int, int]
  • firmwareVersion -- [int, int, int]
  • deviceIdentifier -- int

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions

BrickletRS232V2.on(callback_id, function)
Parameters:
  • callback_id -- int
  • function -- function

Registers the given function with the given callback_id.

The available callback IDs with corresponding function signatures are listed below.

BrickletRS232V2.enableReadCallback([returnCallback][, errorCallback])
Callback:undefined

Enables the CALLBACK_READ callback.

By default the callback is disabled.

BrickletRS232V2.disableReadCallback([returnCallback][, errorCallback])
Callback:undefined

Disables the CALLBACK_READ callback.

By default the callback is disabled.

BrickletRS232V2.isReadCallbackEnabled([returnCallback][, errorCallback])
Callback:
  • enabled -- boolean

Returns true if the CALLBACK_READ callback is enabled, false otherwise.

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the on() function of the device object. The first parameter is the callback ID and the second parameter the callback function:

rs232V2.on(BrickletRS232V2.CALLBACK_EXAMPLE,
    function (param) {
        console.log(param);
    }
);

The available constants with inherent number and type of parameters are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

BrickletRS232V2.CALLBACK_READ_LOW_LEVEL
Parameters:
  • messageLength -- int
  • messageChunkOffset -- int
  • messageChunkData -- [char, char, ..57x.., char]

This callback is called if new data is available.

To enable this callback, use enableReadCallback().

BrickletRS232V2.CALLBACK_ERROR_COUNT
Parameters:
  • errorCountOverrun -- int
  • errorCountParity -- int

This callback is called if a new error occurs. It returns the current overrun and parity error count.

Constants

BrickletRS232V2.DEVICE_IDENTIFIER

This constant is used to identify a RS232 Bricklet 2.0.

The getIdentity() function and the CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletRS232V2.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a RS232 Bricklet 2.0.