Go - Temperature Bricklet

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

An installation guide for the Go API bindings is part of their general description. Additional documentation can be found on godoc.org.

Examples

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

Simple

Download (example_simple.go)

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package main

import (
    "fmt"
    "github.com/Tinkerforge/go-api-bindings/ipconnection"
    "github.com/Tinkerforge/go-api-bindings/temperature_bricklet"
)

const ADDR string = "localhost:4223"
const UID string = "XYZ" // Change XYZ to the UID of your Temperature Bricklet.

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    t, _ := temperature_bricklet.New(UID, &ipcon) // Create device object.

    ipcon.Connect(ADDR) // Connect to brickd.
    defer ipcon.Disconnect()
    // Don't use device before ipcon is connected.

    // Get current temperature.
    temperature, _ := t.GetTemperature()
    fmt.Printf("Temperature: %f °C\n", float64(temperature)/100.0)

    fmt.Print("Press enter to exit.")
    fmt.Scanln()
}

Callback

Download (example_callback.go)

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package main

import (
    "fmt"
    "github.com/Tinkerforge/go-api-bindings/ipconnection"
    "github.com/Tinkerforge/go-api-bindings/temperature_bricklet"
)

const ADDR string = "localhost:4223"
const UID string = "XYZ" // Change XYZ to the UID of your Temperature Bricklet.

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    t, _ := temperature_bricklet.New(UID, &ipcon) // Create device object.

    ipcon.Connect(ADDR) // Connect to brickd.
    defer ipcon.Disconnect()
    // Don't use device before ipcon is connected.

    t.RegisterTemperatureCallback(func(temperature int16) {
        fmt.Printf("Temperature: %f °C\n", float64(temperature)/100.0)
    })

    // Set period for temperature receiver to 1s (1000ms).
    // Note: The temperature callback is only called every second
    //       if the temperature has changed since the last call!
    t.SetTemperatureCallbackPeriod(1000)

    fmt.Print("Press enter to exit.")
    fmt.Scanln()
}

Threshold

Download (example_threshold.go)

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package main

import (
    "fmt"
    "github.com/Tinkerforge/go-api-bindings/ipconnection"
    "github.com/Tinkerforge/go-api-bindings/temperature_bricklet"
)

const ADDR string = "localhost:4223"
const UID string = "XYZ" // Change XYZ to the UID of your Temperature Bricklet.

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    t, _ := temperature_bricklet.New(UID, &ipcon) // Create device object.

    ipcon.Connect(ADDR) // Connect to brickd.
    defer ipcon.Disconnect()
    // Don't use device before ipcon is connected.

    // Get threshold receivers with a debounce time of 10 seconds (10000ms).
    t.SetDebouncePeriod(10000)

    t.RegisterTemperatureReachedCallback(func(temperature int16) {
        fmt.Printf("Temperature: %f °C\n", float64(temperature)/100.0)
        fmt.Println("It is too hot, we need air conditioning!")
    })

    // Configure threshold for temperature "greater than 30 °C".
    t.SetTemperatureCallbackThreshold('>', 30*100, 0)

    fmt.Print("Press enter to exit.")
    fmt.Scanln()
}

API

The Temperature Bricklet API is defined in the package github.com/Tinkerforge/go-api-bindings/temperature_bricklet

Nearly every function of the Go bindings can return an DeviceError, implementing the error interface. The error can have one of the following values:

  • DeviceErrorSuccess = 0
  • DeviceErrorInvalidParameter = 1
  • DeviceErrorFunctionNotSupported = 2
  • DeviceErrorUnknownError = 3

which correspond to the values returned from Bricks and Bricklets.

All functions listed below are thread-safe.

Basic Functions

func temperature_bricklet.New(uid string, ipcon *IPConnection) (device TemperatureBricklet, err error)

Creates a new TemperatureBricklet object with the unique device ID uid and adds it to the IPConnection ipcon:

device, err := temperature_bricklet.New("YOUR_DEVICE_UID", &ipcon)

This device object can be used after the IPConnection has been connected (see examples above).

func (*TemperatureBricklet) GetTemperature() (temperature int16, err error)

Returns the temperature of the sensor. The value has a range of -2500 to 8500 and is given in °C/100, e.g. a value of 4223 means that a temperature of 42.23 °C is measured.

If you want to get the temperature periodically, it is recommended to use the RegisterTemperatureCallback callback and set the period with SetTemperatureCallbackPeriod().

Advanced Functions

func (*TemperatureBricklet) SetI2CMode(mode I2CMode) (err error)

Sets the I2C mode. Possible modes are:

  • 0: Fast (400kHz, default)
  • 1: Slow (100kHz)

If you have problems with obvious outliers in the Temperature Bricklet measurements, they may be caused by EMI issues. In this case it may be helpful to lower the I2C speed.

It is however not recommended to lower the I2C speed in applications where a high throughput needs to be achieved.

The following constants are available for this function:

  • temperature_bricklet.I2CModeFast = 0
  • temperature_bricklet.I2CModeSlow = 1

New in version 2.0.1 (Plugin).

func (*TemperatureBricklet) GetI2CMode() (mode I2CMode, err error)

Returns the I2C mode as set by SetI2CMode().

The following constants are available for this function:

  • temperature_bricklet.I2CModeFast = 0
  • temperature_bricklet.I2CModeSlow = 1

New in version 2.0.1 (Plugin).

func (*TemperatureBricklet) GetAPIVersion() (apiVersion [3]uint8, err error)

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.

func (*TemperatureBricklet) GetResponseExpected(functionId Function) (responseExpected bool, err error)

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.

The following constants are available for this function:

  • temperature_bricklet.FunctionSetTemperatureCallbackPeriod = 2
  • temperature_bricklet.FunctionSetTemperatureCallbackThreshold = 4
  • temperature_bricklet.FunctionSetDebouncePeriod = 6
  • temperature_bricklet.FunctionSetI2CMode = 10
func (*TemperatureBricklet) SetResponseExpected(functionId Function, responseExpected bool) (err error)

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 constants are available for this function:

  • temperature_bricklet.FunctionSetTemperatureCallbackPeriod = 2
  • temperature_bricklet.FunctionSetTemperatureCallbackThreshold = 4
  • temperature_bricklet.FunctionSetDebouncePeriod = 6
  • temperature_bricklet.FunctionSetI2CMode = 10
func (*TemperatureBricklet) SetResponseExpectedAll(responseExpected bool) (err error)

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

func (*TemperatureBricklet) GetIdentity() (uid string, connectedUid string, position rune, hardwareVersion [3]uint8, firmwareVersion [3]uint8, deviceIdentifier uint16, err error)

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

func (*TemperatureBricklet) SetTemperatureCallbackPeriod(period uint32) (err error)

Sets the period in ms with which the RegisterTemperatureCallback callback is triggered periodically. A value of 0 turns the callback off.

The RegisterTemperatureCallback callback is only triggered if the temperature has changed since the last triggering.

The default value is 0.

func (*TemperatureBricklet) GetTemperatureCallbackPeriod() (period uint32, err error)

Returns the period as set by SetTemperatureCallbackPeriod().

func (*TemperatureBricklet) SetTemperatureCallbackThreshold(option ThresholdOption, min int16, max int16) (err error)

Sets the thresholds for the RegisterTemperatureReachedCallback callback.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the temperature is outside the min and max values
'i' Callback is triggered when the temperature is inside the min and max values
'<' Callback is triggered when the temperature is smaller than the min value (max is ignored)
'>' Callback is triggered when the temperature is greater than the min value (max is ignored)

The default value is ('x', 0, 0).

The following constants are available for this function:

  • temperature_bricklet.ThresholdOptionOff = 'x'
  • temperature_bricklet.ThresholdOptionOutside = 'o'
  • temperature_bricklet.ThresholdOptionInside = 'i'
  • temperature_bricklet.ThresholdOptionSmaller = '<'
  • temperature_bricklet.ThresholdOptionGreater = '>'
func (*TemperatureBricklet) GetTemperatureCallbackThreshold() (option ThresholdOption, min int16, max int16, err error)

Returns the threshold as set by SetTemperatureCallbackThreshold().

The following constants are available for this function:

  • temperature_bricklet.ThresholdOptionOff = 'x'
  • temperature_bricklet.ThresholdOptionOutside = 'o'
  • temperature_bricklet.ThresholdOptionInside = 'i'
  • temperature_bricklet.ThresholdOptionSmaller = '<'
  • temperature_bricklet.ThresholdOptionGreater = '>'
func (*TemperatureBricklet) SetDebouncePeriod(debounce uint32) (err error)

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

func (*TemperatureBricklet) GetDebouncePeriod() (debounce uint32, err error)

Returns the debounce period as set by SetDebouncePeriod().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding Register*Callback function, which returns a unique callback ID. This ID can be used to deregister the callback later.

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.

func (*TemperatureBricklet) RegisterTemperatureCallback(func(temperature int16)) (registrationId uint64)

A callback can be registered for this event with the RegisterTemperatureCallback() function. This function returns the ID of the registered callback. An added callback can be removed with the DeregisterTemperatureCallback(registrationId uint64) function.

This callback is triggered periodically with the period that is set by SetTemperatureCallbackPeriod(). The callback parameter is the temperature of the sensor.

The RegisterTemperatureCallback callback is only triggered if the temperature has changed since the last triggering.

func (*TemperatureBricklet) RegisterTemperatureReachedCallback(func(temperature int16)) (registrationId uint64)

A callback can be registered for this event with the RegisterTemperatureReachedCallback() function. This function returns the ID of the registered callback. An added callback can be removed with the DeregisterTemperatureReachedCallback(registrationId uint64) function.

This callback is triggered when the threshold as set by SetTemperatureCallbackThreshold() is reached. The callback parameter is the temperature of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by SetDebouncePeriod().

Constants

temperature_bricklet.DeviceIdentifier

This constant is used to identify a Temperature Bricklet.

The GetIdentity() function and the (*IPConnection) RegisterEnumerateCallback callback of the IPConnection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

temperature_bricklet.DeviceDisplayName

This constant represents the human readable name of a Temperature Bricklet.