JavaScript - One Wire Bricklet

This is the description of the JavaScript API bindings for the One Wire Bricklet. General information and technical specifications for the One Wire Bricklet 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).

Read DS 18B 20Temperature (Node.js)

Download (ExampleReadDS18B20Temperature.js)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
var Tinkerforge = require('./Tinkerforge.js');

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

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

var writeCommandPromise = function(ow, identifier, command) {
    var promise = new Promise(function(resolve, reject) {
        ow.writeCommand(identifier, command, function(status) {
            resolve(status);
        });
    });

    return promise;
}

var writePromise = function(ow, data) {
    var promise = new Promise(function(resolve, reject) {
        ow.write(data, function(status) {
            resolve(status);
        });
    });

    return promise;
}

var readPromise = function(ow) {
    var promise = new Promise(function(resolve, reject) {
        ow.read(function(data, status) {
            resolve(data, status);
        });
    });

    return promise;
}

var timeoutPromise = function(millis) {
    var promise = new Promise(function(resolve, reject) {
        setTimeout(function () {
            resolve();
        }, millis);
    });

    return promise;
}

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,
    async function (connectReason) {
        await writeCommandPromise(ow, 0, 78); // WRITE SCRATCHPAD
        await writePromise(ow, 0); // ALARM H (unused)
        await writePromise(ow, 0); // ALARM L (unused)
        await writePromise(ow, 127); // CONFIGURATION: 12 bit mode

        // Read temperature 10 times
        for(var i = 0; i < 10; ++i) {
            await writeCommandPromise(ow, 0, 68); // CONVERT T (start temperature conversion)
            await timeoutPromise(1000);
            await writeCommandPromise(ow, 0, 190); // READ SCRATCHPAD

            var t_low = await readPromise(ow);
            var t_high = await readPromise(ow);
            console.log('Temperature: ' + ((t_low | (t_high << 8)) / 16.0) + ' °C');
        }
    }
);

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

Read DS 18B 20Temperature (HTML)

Download (ExampleReadDS18B20Temperature.html), Test (ExampleReadDS18B20Temperature.html)

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
<!DOCTYPE html>

<!-- FIXME: This example is incomplete -->

<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>One Wire Bricklet Read DS18B20 Temperature 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 ow = new Tinkerforge.BrickletOneWire(UID, ipcon); // Create device object

                var writeCommandPromise = function(ow, identifier, command) {
                    var promise = new Promise(function(resolve, reject) {
                        ow.writeCommand(identifier, command, function(status) {
                            resolve(status);
                        });
                    });

                    return promise;
                }

                var writePromise = function(ow, data) {
                    var promise = new Promise(function(resolve, reject) {
                        ow.write(data, function(status) {
                            resolve(status);
                        });
                    });

                    return promise;
                }

                var readPromise = function(ow) {
                    var promise = new Promise(function(resolve, reject) {
                        ow.read(function(data, status) {
                            resolve(data, status);
                        });
                    });

                    return promise;
                }

                var timeoutPromise = function(millis) {
                    var promise = new Promise(function(resolve, reject) {
                        setTimeout(function () {
                            resolve();
                        }, millis);
                    });

                    return promise;
                }

                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,
                    async function (connectReason) {
                        await writeCommandPromise(ow, 0, 78); // WRITE SCRATCHPAD
                        await writePromise(ow, 0); // ALARM H (unused)
                        await writePromise(ow, 0); // ALARM L (unused)
                        await writePromise(ow, 127); // CONFIGURATION: 12 bit mode

                        // Read temperature 10 times
                        for(var i = 0; i < 10; ++i) {
                            await writeCommandPromise(ow, 0, 68); // CONVERT T (start temperature conversion)
                            await timeoutPromise(1000);
                            await writeCommandPromise(ow, 0, 190); // READ SCRATCHPAD

                            var t_low = await readPromise(ow);
                            var t_high = await readPromise(ow);
                            textArea.value += 'Temperature: ' + ((t_low | (t_high << 8)) / 16.0) + ' °C';
                        }
                    }
                );
            }
        </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 BrickletOneWire(uid, ipcon)
Parameters:
  • uid -- string
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

var oneWire = new BrickletOneWire("YOUR_DEVICE_UID", ipcon);

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

BrickletOneWire.searchBusLowLevel([returnCallback][, errorCallback])
Callback:
  • identifierLength -- int
  • identifierChunkOffset -- int
  • identifierChunkData -- [int, int, ..4x.., int]
  • status -- int

Returns a list of up to 64 identifiers of the connected 1-Wire devices. Each identifier is 64-bit and consists of 8-bit family code, 48-bit ID and 8-bit CRC.

To get these identifiers the Bricklet runs the SEARCH ROM algorithm, as defined by Maxim.

The following constants are available for this function:

  • BrickletOneWire.STATUS_OK = 0
  • BrickletOneWire.STATUS_BUSY = 1
  • BrickletOneWire.STATUS_NO_PRESENCE = 2
  • BrickletOneWire.STATUS_TIMEOUT = 3
  • BrickletOneWire.STATUS_ERROR = 4
BrickletOneWire.resetBus([returnCallback][, errorCallback])
Callback:
  • status -- int

Resets the bus with the 1-Wire reset operation.

The following constants are available for this function:

  • BrickletOneWire.STATUS_OK = 0
  • BrickletOneWire.STATUS_BUSY = 1
  • BrickletOneWire.STATUS_NO_PRESENCE = 2
  • BrickletOneWire.STATUS_TIMEOUT = 3
  • BrickletOneWire.STATUS_ERROR = 4
BrickletOneWire.write(data[, returnCallback][, errorCallback])
Parameters:
  • data -- int
Callback:
  • status -- int

Writes a byte of data to the 1-Wire bus.

The following constants are available for this function:

  • BrickletOneWire.STATUS_OK = 0
  • BrickletOneWire.STATUS_BUSY = 1
  • BrickletOneWire.STATUS_NO_PRESENCE = 2
  • BrickletOneWire.STATUS_TIMEOUT = 3
  • BrickletOneWire.STATUS_ERROR = 4
BrickletOneWire.read([returnCallback][, errorCallback])
Callback:
  • data -- int
  • status -- int

Reads a byte of data from the 1-Wire bus.

The following constants are available for this function:

  • BrickletOneWire.STATUS_OK = 0
  • BrickletOneWire.STATUS_BUSY = 1
  • BrickletOneWire.STATUS_NO_PRESENCE = 2
  • BrickletOneWire.STATUS_TIMEOUT = 3
  • BrickletOneWire.STATUS_ERROR = 4
BrickletOneWire.writeCommand(identifier, command[, returnCallback][, errorCallback])
Parameters:
  • identifier -- int
  • command -- int
Callback:
  • status -- int

Writes a command to the 1-Wire device with the given identifier. You can obtain the identifier by calling searchBus(). The MATCH ROM operation is used to write the command.

If you only have one device connected or want to broadcast to all devices you can set the identifier to 0. In this case the SKIP ROM operation is used to write the command.

The following constants are available for this function:

  • BrickletOneWire.STATUS_OK = 0
  • BrickletOneWire.STATUS_BUSY = 1
  • BrickletOneWire.STATUS_NO_PRESENCE = 2
  • BrickletOneWire.STATUS_TIMEOUT = 3
  • BrickletOneWire.STATUS_ERROR = 4

Advanced Functions

BrickletOneWire.setCommunicationLEDConfig(config[, returnCallback][, errorCallback])
Parameters:
  • config -- int
Callback:

undefined

Sets the communication LED configuration. By default the LED shows 1-wire communication traffic by flickering.

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

If the Bricklet is in bootloader mode, the LED is off.

The following constants are available for this function:

  • BrickletOneWire.COMMUNICATION_LED_CONFIG_OFF = 0
  • BrickletOneWire.COMMUNICATION_LED_CONFIG_ON = 1
  • BrickletOneWire.COMMUNICATION_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletOneWire.COMMUNICATION_LED_CONFIG_SHOW_COMMUNICATION = 3
BrickletOneWire.getCommunicationLEDConfig([returnCallback][, errorCallback])
Callback:
  • config -- int

Returns the configuration as set by setCommunicationLEDConfig()

The following constants are available for this function:

  • BrickletOneWire.COMMUNICATION_LED_CONFIG_OFF = 0
  • BrickletOneWire.COMMUNICATION_LED_CONFIG_ON = 1
  • BrickletOneWire.COMMUNICATION_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletOneWire.COMMUNICATION_LED_CONFIG_SHOW_COMMUNICATION = 3
BrickletOneWire.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.

BrickletOneWire.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.

BrickletOneWire.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:

  • BrickletOneWire.FUNCTION_SET_COMMUNICATION_LED_CONFIG = 6
  • BrickletOneWire.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletOneWire.FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletOneWire.FUNCTION_RESET = 243
  • BrickletOneWire.FUNCTION_WRITE_UID = 248
BrickletOneWire.setResponseExpectedAll(responseExpected)
Parameters:
  • responseExpected -- boolean

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

BrickletOneWire.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.

BrickletOneWire.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:

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

Returns the current bootloader mode, see setBootloaderMode().

The following constants are available for this function:

  • BrickletOneWire.BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletOneWire.BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletOneWire.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletOneWire.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletOneWire.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickletOneWire.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.

BrickletOneWire.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.

BrickletOneWire.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:

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

Returns the configuration as set by setStatusLEDConfig()

The following constants are available for this function:

  • BrickletOneWire.STATUS_LED_CONFIG_OFF = 0
  • BrickletOneWire.STATUS_LED_CONFIG_ON = 1
  • BrickletOneWire.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletOneWire.STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletOneWire.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.

BrickletOneWire.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!

BrickletOneWire.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.

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

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

BrickletOneWire.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.

Constants

BrickletOneWire.DEVICE_IDENTIFIER

This constant is used to identify a One Wire 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.

BrickletOneWire.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a One Wire Bricklet.