Go - Ambient Light Bricklet 2.0

This is the description of the Go API bindings for the Ambient Light Bricklet 2.0. General information and technical specifications for the Ambient Light Bricklet 2.0 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/ambient_light_v2_bricklet"
    "github.com/Tinkerforge/go-api-bindings/ipconnection"
)

const ADDR string = "localhost:4223"
const UID string = "XYZ" // Change XYZ to the UID of your Ambient Light Bricklet 2.0.

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    al, _ := ambient_light_v2_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 illuminance.
    illuminance, _ := al.GetIlluminance()
    fmt.Printf("Illuminance: %f lx\n", float64(illuminance)/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/ambient_light_v2_bricklet"
    "github.com/Tinkerforge/go-api-bindings/ipconnection"
)

const ADDR string = "localhost:4223"
const UID string = "XYZ" // Change XYZ to the UID of your Ambient Light Bricklet 2.0.

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    al, _ := ambient_light_v2_bricklet.New(UID, &ipcon) // Create device object.

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

    al.RegisterIlluminanceCallback(func(illuminance uint32) {
        fmt.Printf("Illuminance: %f lx\n", float64(illuminance)/100.0)
    })

    // Set period for illuminance receiver to 1s (1000ms).
    // Note: The illuminance callback is only called every second
    //       if the illuminance has changed since the last call!
    al.SetIlluminanceCallbackPeriod(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/ambient_light_v2_bricklet"
    "github.com/Tinkerforge/go-api-bindings/ipconnection"
)

const ADDR string = "localhost:4223"
const UID string = "XYZ" // Change XYZ to the UID of your Ambient Light Bricklet 2.0.

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    al, _ := ambient_light_v2_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).
    al.SetDebouncePeriod(10000)

    al.RegisterIlluminanceReachedCallback(func(illuminance uint32) {
        fmt.Printf("Illuminance: %f lx\n", float64(illuminance)/100.0)
        fmt.Println("Too bright, close the curtains!")
    })

    // Configure threshold for illuminance "greater than 500 lx".
    al.SetIlluminanceCallbackThreshold('>', 500*100, 0)

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

API

The Ambient Light Bricklet 2.0 API is defined in the package github.com/Tinkerforge/go-api-bindings/ambient_light_v2_bricklet

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

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

which correspond to the values returned from Bricks and Bricklets.

All functions listed below are thread-safe.

Basic Functions

func ambient_light_v2_bricklet.New(uid string, ipcon *IPConnection) (device AmbientLightV2Bricklet, err error)
Parameters:
  • uid – Type: string
  • ipcon – Type: *IPConnection
Returns:
  • device – Type: AmbientLightV2Bricklet
  • err – Type: error

Creates a new AmbientLightV2Bricklet object with the unique device ID uid and adds it to the IPConnection ipcon:

device, err := ambient_light_v2_bricklet.New("YOUR_DEVICE_UID", &ipcon)

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

func (*AmbientLightV2Bricklet) GetIlluminance() (illuminance uint32, err error)
Returns:
  • illuminance – Type: uint32, Unit: 1/100 lx, Range: [0 to 232 - 1]
  • err – Type: error

Returns the illuminance of the ambient light sensor. The measurement range goes up to about 100000lux, but above 64000lux the precision starts to drop.

Changed in version 2.0.2 (Plugin): An illuminance of 0lux indicates that the sensor is saturated and the configuration should be modified, see SetConfiguration().

If you want to get the illuminance periodically, it is recommended to use the RegisterIlluminanceCallback callback and set the period with SetIlluminanceCallbackPeriod().

Advanced Functions

func (*AmbientLightV2Bricklet) SetConfiguration(illuminanceRange uint8, integrationTime uint8) (err error)
Parameters:
  • illuminanceRange – Type: uint8, Range: See constants, Default: 3
  • integrationTime – Type: uint8, Range: See constants, Default: 3
Returns:
  • err – Type: error

Sets the configuration. It is possible to configure an illuminance range between 0-600lux and 0-64000lux and an integration time between 50ms and 400ms.

New in version 2.0.2 (Plugin): The unlimited illuminance range allows to measure up to about 100000lux, but above 64000lux the precision starts to drop.

A smaller illuminance range increases the resolution of the data. A longer integration time will result in less noise on the data.

Changed in version 2.0.2 (Plugin): If the actual measure illuminance is out-of-range then the current illuminance range maximum +0.01lux is reported by GetIlluminance() and the RegisterIlluminanceCallback callback. For example, 800001 for the 0-8000lux range.

Changed in version 2.0.2 (Plugin): With a long integration time the sensor might be saturated before the measured value reaches the maximum of the selected illuminance range. In this case 0lux is reported by GetIlluminance() and the RegisterIlluminanceCallback callback.

If the measurement is out-of-range or the sensor is saturated then you should configure the next higher illuminance range. If the highest range is already in use, then start to reduce the integration time.

The following constants are available for this function:

For illuminanceRange:

  • ambient_light_v2_bricklet.IlluminanceRangeUnlimited = 6
  • ambient_light_v2_bricklet.IlluminanceRange64000Lux = 0
  • ambient_light_v2_bricklet.IlluminanceRange32000Lux = 1
  • ambient_light_v2_bricklet.IlluminanceRange16000Lux = 2
  • ambient_light_v2_bricklet.IlluminanceRange8000Lux = 3
  • ambient_light_v2_bricklet.IlluminanceRange1300Lux = 4
  • ambient_light_v2_bricklet.IlluminanceRange600Lux = 5

For integrationTime:

  • ambient_light_v2_bricklet.IntegrationTime50ms = 0
  • ambient_light_v2_bricklet.IntegrationTime100ms = 1
  • ambient_light_v2_bricklet.IntegrationTime150ms = 2
  • ambient_light_v2_bricklet.IntegrationTime200ms = 3
  • ambient_light_v2_bricklet.IntegrationTime250ms = 4
  • ambient_light_v2_bricklet.IntegrationTime300ms = 5
  • ambient_light_v2_bricklet.IntegrationTime350ms = 6
  • ambient_light_v2_bricklet.IntegrationTime400ms = 7
func (*AmbientLightV2Bricklet) GetConfiguration() (illuminanceRange uint8, integrationTime uint8, err error)
Returns:
  • illuminanceRange – Type: uint8, Range: See constants, Default: 3
  • integrationTime – Type: uint8, Range: See constants, Default: 3
  • err – Type: error

Returns the configuration as set by SetConfiguration().

The following constants are available for this function:

For illuminanceRange:

  • ambient_light_v2_bricklet.IlluminanceRangeUnlimited = 6
  • ambient_light_v2_bricklet.IlluminanceRange64000Lux = 0
  • ambient_light_v2_bricklet.IlluminanceRange32000Lux = 1
  • ambient_light_v2_bricklet.IlluminanceRange16000Lux = 2
  • ambient_light_v2_bricklet.IlluminanceRange8000Lux = 3
  • ambient_light_v2_bricklet.IlluminanceRange1300Lux = 4
  • ambient_light_v2_bricklet.IlluminanceRange600Lux = 5

For integrationTime:

  • ambient_light_v2_bricklet.IntegrationTime50ms = 0
  • ambient_light_v2_bricklet.IntegrationTime100ms = 1
  • ambient_light_v2_bricklet.IntegrationTime150ms = 2
  • ambient_light_v2_bricklet.IntegrationTime200ms = 3
  • ambient_light_v2_bricklet.IntegrationTime250ms = 4
  • ambient_light_v2_bricklet.IntegrationTime300ms = 5
  • ambient_light_v2_bricklet.IntegrationTime350ms = 6
  • ambient_light_v2_bricklet.IntegrationTime400ms = 7
func (*AmbientLightV2Bricklet) GetIdentity() (uid string, connectedUid string, position rune, hardwareVersion [3]uint8, firmwareVersion [3]uint8, deviceIdentifier uint16, err error)
Returns:
  • uid – Type: string, Length: up to 8
  • connectedUid – Type: string, Length: up to 8
  • position – Type: rune, Range: ['a' to 'h', 'i', 'z']
  • hardwareVersion – Type: [3]uint8
    • 0: major – Type: uint8, Range: [0 to 255]
    • 1: minor – Type: uint8, Range: [0 to 255]
    • 2: revision – Type: uint8, Range: [0 to 255]
  • firmwareVersion – Type: [3]uint8
    • 0: major – Type: uint8, Range: [0 to 255]
    • 1: minor – Type: uint8, Range: [0 to 255]
    • 2: revision – Type: uint8, Range: [0 to 255]
  • deviceIdentifier – Type: uint16, Range: [0 to 216 - 1]
  • err – Type: 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', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). The Raspberry Pi HAT (Zero) Brick is always at position 'i' and the Bricklet connected to an Isolator Bricklet is always as position 'z'.

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

Callback Configuration Functions

func (*AmbientLightV2Bricklet) SetIlluminanceCallbackPeriod(period uint32) (err error)
Parameters:
  • period – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Returns:
  • err – Type: error

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

The RegisterIlluminanceCallback callback is only triggered if the illuminance has changed since the last triggering.

func (*AmbientLightV2Bricklet) GetIlluminanceCallbackPeriod() (period uint32, err error)
Returns:
  • period – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • err – Type: error

Returns the period as set by SetIlluminanceCallbackPeriod().

func (*AmbientLightV2Bricklet) SetIlluminanceCallbackThreshold(option rune, min uint32, max uint32) (err error)
Parameters:
  • option – Type: rune, Range: See constants, Default: 'x'
  • min – Type: uint32, Unit: 1/100 lx, Range: [0 to 232 - 1], Default: 0
  • max – Type: uint32, Unit: 1/100 lx, Range: [0 to 232 - 1], Default: 0
Returns:
  • err – Type: error

Sets the thresholds for the RegisterIlluminanceReachedCallback callback.

The following options are possible:

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

The following constants are available for this function:

For option:

  • ambient_light_v2_bricklet.ThresholdOptionOff = 'x'
  • ambient_light_v2_bricklet.ThresholdOptionOutside = 'o'
  • ambient_light_v2_bricklet.ThresholdOptionInside = 'i'
  • ambient_light_v2_bricklet.ThresholdOptionSmaller = '<'
  • ambient_light_v2_bricklet.ThresholdOptionGreater = '>'
func (*AmbientLightV2Bricklet) GetIlluminanceCallbackThreshold() (option rune, min uint32, max uint32, err error)
Returns:
  • option – Type: rune, Range: See constants, Default: 'x'
  • min – Type: uint32, Unit: 1/100 lx, Range: [0 to 232 - 1], Default: 0
  • max – Type: uint32, Unit: 1/100 lx, Range: [0 to 232 - 1], Default: 0
  • err – Type: error

Returns the threshold as set by SetIlluminanceCallbackThreshold().

The following constants are available for this function:

For option:

  • ambient_light_v2_bricklet.ThresholdOptionOff = 'x'
  • ambient_light_v2_bricklet.ThresholdOptionOutside = 'o'
  • ambient_light_v2_bricklet.ThresholdOptionInside = 'i'
  • ambient_light_v2_bricklet.ThresholdOptionSmaller = '<'
  • ambient_light_v2_bricklet.ThresholdOptionGreater = '>'
func (*AmbientLightV2Bricklet) SetDebouncePeriod(debounce uint32) (err error)
Parameters:
  • debounce – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100
Returns:
  • err – Type: error

Sets the period with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

func (*AmbientLightV2Bricklet) GetDebouncePeriod() (debounce uint32, err error)
Returns:
  • debounce – Type: uint32, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100
  • err – Type: 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 with the corresponding Deregister*Callback function.

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 (*AmbientLightV2Bricklet) RegisterIlluminanceCallback(func(illuminance uint32)) (registrationId uint64)
Callback Parameters:
  • illuminance – Type: uint32, Unit: 1/100 lx, Range: [0 to 232 - 1]
Returns:
  • registrationId – Type: uint64

This callback is triggered periodically with the period that is set by SetIlluminanceCallbackPeriod(). The callback parameter is the illuminance of the ambient light sensor.

The RegisterIlluminanceCallback callback is only triggered if the illuminance has changed since the last triggering.

func (*AmbientLightV2Bricklet) RegisterIlluminanceReachedCallback(func(illuminance uint32)) (registrationId uint64)
Callback Parameters:
  • illuminance – Type: uint32, Unit: 1/100 lx, Range: [0 to 232 - 1]
Returns:
  • registrationId – Type: uint64

This callback is triggered when the threshold as set by SetIlluminanceCallbackThreshold() is reached. The callback parameter is the illuminance of the ambient light sensor.

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

Virtual Functions

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

func (*AmbientLightV2Bricklet) GetAPIVersion() (apiVersion [3]uint8, err error)
Returns:
  • apiVersion – Type: [3]uint8
    • 0: major – Type: uint8, Range: [0 to 255]
    • 1: minor – Type: uint8, Range: [0 to 255]
    • 2: revision – Type: uint8, Range: [0 to 255]
  • err – Type: error

Returns the version of the API definition 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 (*AmbientLightV2Bricklet) GetResponseExpected(functionId uint8) (responseExpected bool, err error)
Parameters:
  • functionId – Type: uint8, Range: See constants
Returns:
  • responseExpected – Type: bool
  • err – Type: 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

  • ambient_light_v2_bricklet.FunctionSetIlluminanceCallbackPeriod = 2
  • ambient_light_v2_bricklet.FunctionSetIlluminanceCallbackThreshold = 4
  • ambient_light_v2_bricklet.FunctionSetDebouncePeriod = 6
  • ambient_light_v2_bricklet.FunctionSetConfiguration = 8
func (*AmbientLightV2Bricklet) SetResponseExpected(functionId uint8, responseExpected bool) (err error)
Parameters:
  • functionId – Type: uint8, Range: See constants
  • responseExpected – Type: bool
Returns:
  • err – Type: 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

  • ambient_light_v2_bricklet.FunctionSetIlluminanceCallbackPeriod = 2
  • ambient_light_v2_bricklet.FunctionSetIlluminanceCallbackThreshold = 4
  • ambient_light_v2_bricklet.FunctionSetDebouncePeriod = 6
  • ambient_light_v2_bricklet.FunctionSetConfiguration = 8
func (*AmbientLightV2Bricklet) SetResponseExpectedAll(responseExpected bool) (err error)
Parameters:
  • responseExpected – Type: bool
Returns:
  • err – Type: error

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

Constants

ambient_light_v2_bricklet.DeviceIdentifier

This constant is used to identify a Ambient Light Bricklet 2.0.

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

ambient_light_v2_bricklet.DeviceDisplayName

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