Note
This Bricklet is currently in the prototype stage and the software/hardware as well as the documentation is in an incomplete state.
This is the description of the JavaScript API bindings for the RS232 Bricklet. General information and technical specifications for the RS232 Bricklet are summarized in its hardware description.
An installation guide for the JavaScript API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
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:
The namespace for the JavaScript bindings is Tinkerforge.*.
Parameters: |
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Creates an object with the unique device ID uid:
var rs232 = new BrickletRS232("YOUR_DEVICE_UID", ipcon);
This object can then be used after the IP Connection is connected (see examples above).
Parameters: |
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Callback: |
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Writes a string of up to 60 characters to the RS232 interface. The string can be binary data, ASCII or similar is not necessary.
The length of the string has to be given as an additional parameter.
The return value is the number of bytes that could be written.
See SetConfigurations() for configuration possibilities regarding baudrate, parity and so on.
Callback: |
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Returns the currently buffered message. The maximum length of message is 60. If the length is given as 0, there was no new data available.
Instead of polling with this function, you can also use callbacks. See enableCallback() and CALLBACK_READ_CALLBACK.
Parameters: |
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Callback: | undefined |
Sets the configuration for the RS232 communication. Available options:
The default is: 115200 baud, parity none, 1 stop bit, word length 8, hard-/software flow control off.
The following constants are available for this function:
Callback: |
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Returns the configuration as set by setConfiguration().
The following constants are available for this function:
Return type: | [int, int, int] |
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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.
Parameters: |
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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.
Parameters: |
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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 and callbacks it is always disabled.
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:
Parameters: |
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Changes the response expected flag for all setter and callback configuration functions of this device at once.
Callback: |
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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.
Parameters: |
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Registers a callback with ID id to the function callback. The available IDs with corresponding function signatures are listed below.
Callback: | undefined |
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Enables the CALLBACK_READ_CALLBACK.
By default the callback is disabled.
Callback: | undefined |
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Disables the CALLBACK_READ_CALLBACK.
By default the callback is disabled.
Callback: |
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Returns true if the CALLBACK_READ_CALLBACK is enabled, false otherwise.
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:
rs232.on(BrickletRS232.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.
Parameters: |
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This callback is called if new data is available. The message has a maximum size of 60 characters. The actual length of the message is given in addition.
To enable this callback, use enableCallback().
This constant is used to identify a RS232 Bricklet.
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.