Go - PTC Bricklet

This is the description of the Go API bindings for the PTC Bricklet. General information and technical specifications for the PTC 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/ptc_bricklet"
)

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

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    ptc, _ := ptc_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, _ := ptc.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/ptc_bricklet"
)

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

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

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

    ptc.RegisterTemperatureCallback(func(temperature int32) {
        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!
    ptc.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/ptc_bricklet"
)

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

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

    ptc.RegisterTemperatureReachedCallback(func(temperature int32) {
        fmt.Printf("Temperature: %f °C\n", float64(temperature)/100.0)
    })

    // Configure threshold for temperature "greater than 30 °C".
    ptc.SetTemperatureCallbackThreshold('>', 30*100, 0)

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

API

The PTC Bricklet API is defined in the package github.com/Tinkerforge/go-api-bindings/ptc_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 ptc_bricklet.New(uid string, ipcon *IPConnection) (device PTCBricklet, err error)
Parameters:
  • uid – Type: string
  • ipcon – Type: *IPConnection
Returns:
  • device – Type: PTCBricklet
  • err – Type: error

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

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

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

func (*PTCBricklet) GetTemperature() (temperature int32, err error)
Returns:
  • temperature – Type: int32, Unit: 1/100 °C, Range: [-24600 to 84900]
  • err – Type: error

Returns the temperature of connected sensor.

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

func (*PTCBricklet) IsSensorConnected() (connected bool, err error)
Returns:
  • connected – Type: bool
  • err – Type: error

Returns true if the sensor is connected correctly.

If this function returns false, there is either no Pt100 or Pt1000 sensor connected, the sensor is connected incorrectly or the sensor itself is faulty.

func (*PTCBricklet) SetWireMode(mode uint8) (err error)
Parameters:
  • mode – Type: uint8, Range: See constants, Default: 2
Returns:
  • err – Type: error

Sets the wire mode of the sensor. Possible values are 2, 3 and 4 which correspond to 2-, 3- and 4-wire sensors. The value has to match the jumper configuration on the Bricklet.

The following constants are available for this function:

For mode:

  • ptc_bricklet.WireMode2 = 2
  • ptc_bricklet.WireMode3 = 3
  • ptc_bricklet.WireMode4 = 4
func (*PTCBricklet) GetWireMode() (mode uint8, err error)
Returns:
  • mode – Type: uint8, Range: See constants, Default: 2
  • err – Type: error

Returns the wire mode as set by SetWireMode()

The following constants are available for this function:

For mode:

  • ptc_bricklet.WireMode2 = 2
  • ptc_bricklet.WireMode3 = 3
  • ptc_bricklet.WireMode4 = 4

Advanced Functions

func (*PTCBricklet) GetResistance() (resistance int32, err error)
Returns:
  • resistance – Type: int32, Unit: ? Ω, Range: [-231 to 231 - 1]
  • err – Type: error

Returns the value as measured by the MAX31865 precision delta-sigma ADC.

The value can be converted with the following formulas:

  • Pt100: resistance = (value * 390) / 32768
  • Pt1000: resistance = (value * 3900) / 32768

If you want to get the resistance periodically, it is recommended to use the RegisterResistanceCallback callback and set the period with SetResistanceCallbackPeriod().

func (*PTCBricklet) SetNoiseRejectionFilter(filter uint8) (err error)
Parameters:
  • filter – Type: uint8, Range: See constants, Default: 0
Returns:
  • err – Type: error

Sets the noise rejection filter to either 50Hz (0) or 60Hz (1). Noise from 50Hz or 60Hz power sources (including harmonics of the AC power's fundamental frequency) is attenuated by 82dB.

The following constants are available for this function:

For filter:

  • ptc_bricklet.FilterOption50Hz = 0
  • ptc_bricklet.FilterOption60Hz = 1
func (*PTCBricklet) GetNoiseRejectionFilter() (filter uint8, err error)
Returns:
  • filter – Type: uint8, Range: See constants, Default: 0
  • err – Type: error

Returns the noise rejection filter option as set by SetNoiseRejectionFilter()

The following constants are available for this function:

For filter:

  • ptc_bricklet.FilterOption50Hz = 0
  • ptc_bricklet.FilterOption60Hz = 1
func (*PTCBricklet) 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 (*PTCBricklet) SetTemperatureCallbackPeriod(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 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.

func (*PTCBricklet) GetTemperatureCallbackPeriod() (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 SetTemperatureCallbackPeriod().

func (*PTCBricklet) SetResistanceCallbackPeriod(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 RegisterResistanceCallback callback is triggered periodically. A value of 0 turns the callback off.

The RegisterResistanceCallback callback is only triggered if the resistance has changed since the last triggering.

func (*PTCBricklet) GetResistanceCallbackPeriod() (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 SetResistanceCallbackPeriod().

func (*PTCBricklet) SetTemperatureCallbackThreshold(option rune, min int32, max int32) (err error)
Parameters:
  • option – Type: rune, Range: See constants, Default: 'x'
  • min – Type: int32, Unit: 1/100 °C, Range: [-231 to 231 - 1], Default: 0
  • max – Type: int32, Unit: 1/100 °C, Range: [-231 to 231 - 1], Default: 0
Returns:
  • err – Type: 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 following constants are available for this function:

For option:

  • ptc_bricklet.ThresholdOptionOff = 'x'
  • ptc_bricklet.ThresholdOptionOutside = 'o'
  • ptc_bricklet.ThresholdOptionInside = 'i'
  • ptc_bricklet.ThresholdOptionSmaller = '<'
  • ptc_bricklet.ThresholdOptionGreater = '>'
func (*PTCBricklet) GetTemperatureCallbackThreshold() (option rune, min int32, max int32, err error)
Returns:
  • option – Type: rune, Range: See constants, Default: 'x'
  • min – Type: int32, Unit: 1/100 °C, Range: [-231 to 231 - 1], Default: 0
  • max – Type: int32, Unit: 1/100 °C, Range: [-231 to 231 - 1], Default: 0
  • err – Type: error

Returns the threshold as set by SetTemperatureCallbackThreshold().

The following constants are available for this function:

For option:

  • ptc_bricklet.ThresholdOptionOff = 'x'
  • ptc_bricklet.ThresholdOptionOutside = 'o'
  • ptc_bricklet.ThresholdOptionInside = 'i'
  • ptc_bricklet.ThresholdOptionSmaller = '<'
  • ptc_bricklet.ThresholdOptionGreater = '>'
func (*PTCBricklet) SetResistanceCallbackThreshold(option rune, min int32, max int32) (err error)
Parameters:
  • option – Type: rune, Range: See constants, Default: 'x'
  • min – Type: int32, Unit: ? Ω, Range: [-231 to 231 - 1], Default: 0
  • max – Type: int32, Unit: ? Ω, Range: [-231 to 231 - 1], Default: 0
Returns:
  • err – Type: error

Sets the thresholds for the RegisterResistanceReachedCallback 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 following constants are available for this function:

For option:

  • ptc_bricklet.ThresholdOptionOff = 'x'
  • ptc_bricklet.ThresholdOptionOutside = 'o'
  • ptc_bricklet.ThresholdOptionInside = 'i'
  • ptc_bricklet.ThresholdOptionSmaller = '<'
  • ptc_bricklet.ThresholdOptionGreater = '>'
func (*PTCBricklet) GetResistanceCallbackThreshold() (option rune, min int32, max int32, err error)
Returns:
  • option – Type: rune, Range: See constants, Default: 'x'
  • min – Type: int32, Unit: ? Ω, Range: [-231 to 231 - 1], Default: 0
  • max – Type: int32, Unit: ? Ω, Range: [-231 to 231 - 1], Default: 0
  • err – Type: error

Returns the threshold as set by SetResistanceCallbackThreshold().

The following constants are available for this function:

For option:

  • ptc_bricklet.ThresholdOptionOff = 'x'
  • ptc_bricklet.ThresholdOptionOutside = 'o'
  • ptc_bricklet.ThresholdOptionInside = 'i'
  • ptc_bricklet.ThresholdOptionSmaller = '<'
  • ptc_bricklet.ThresholdOptionGreater = '>'
func (*PTCBricklet) 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 callback

is triggered, if the threshold

keeps being reached.

func (*PTCBricklet) 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().

func (*PTCBricklet) SetSensorConnectedCallbackConfiguration(enabled bool) (err error)
Parameters:
  • enabled – Type: bool, Default: false
Returns:
  • err – Type: error

If you enable this callback, the RegisterSensorConnectedCallback callback is triggered every time a Pt sensor is connected/disconnected.

New in version 2.0.2 (Plugin).

func (*PTCBricklet) GetSensorConnectedCallbackConfiguration() (enabled bool, err error)
Returns:
  • enabled – Type: bool, Default: false
  • err – Type: error

Returns the configuration as set by SetSensorConnectedCallbackConfiguration().

New in version 2.0.2 (Plugin).

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 (*PTCBricklet) RegisterTemperatureCallback(func(temperature int32)) (registrationId uint64)
Callback Parameters:
  • temperature – Type: int32, Unit: 1/100 °C, Range: [-24600 to 84900]
Returns:
  • registrationId – Type: uint64

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

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

func (*PTCBricklet) RegisterTemperatureReachedCallback(func(temperature int32)) (registrationId uint64)
Callback Parameters:
  • temperature – Type: int32, Unit: 1/100 °C, Range: [-24600 to 84900]
Returns:
  • registrationId – Type: uint64

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

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

func (*PTCBricklet) RegisterResistanceCallback(func(resistance int32)) (registrationId uint64)
Callback Parameters:
  • resistance – Type: int32, Unit: ? Ω, Range: [-231 to 231 - 1]
Returns:
  • registrationId – Type: uint64

This callback is triggered periodically with the period that is set by SetResistanceCallbackPeriod(). The callback parameter is the resistance of the connected sensor.

The RegisterResistanceCallback callback is only triggered if the resistance has changed since the last triggering.

func (*PTCBricklet) RegisterResistanceReachedCallback(func(resistance int32)) (registrationId uint64)
Callback Parameters:
  • resistance – Type: int32, Unit: ? Ω, Range: [-231 to 231 - 1]
Returns:
  • registrationId – Type: uint64

This callback is triggered when the threshold as set by SetResistanceCallbackThreshold() is reached. The callback parameter is the resistance of the connected sensor.

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

func (*PTCBricklet) RegisterSensorConnectedCallback(func(connected bool)) (registrationId uint64)
Callback Parameters:
  • connected – Type: bool
Returns:
  • registrationId – Type: uint64

This callback is triggered periodically according to the configuration set by SetSensorConnectedCallbackConfiguration().

The callback parameter is the same as IsSensorConnected().

New in version 2.0.2 (Plugin).

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 (*PTCBricklet) 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 (*PTCBricklet) 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:

  • ptc_bricklet.FunctionSetTemperatureCallbackPeriod = 3
  • ptc_bricklet.FunctionSetResistanceCallbackPeriod = 5
  • ptc_bricklet.FunctionSetTemperatureCallbackThreshold = 7
  • ptc_bricklet.FunctionSetResistanceCallbackThreshold = 9
  • ptc_bricklet.FunctionSetDebouncePeriod = 11
  • ptc_bricklet.FunctionSetNoiseRejectionFilter = 17
  • ptc_bricklet.FunctionSetWireMode = 20
  • ptc_bricklet.FunctionSetSensorConnectedCallbackConfiguration = 22
func (*PTCBricklet) 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:

  • ptc_bricklet.FunctionSetTemperatureCallbackPeriod = 3
  • ptc_bricklet.FunctionSetResistanceCallbackPeriod = 5
  • ptc_bricklet.FunctionSetTemperatureCallbackThreshold = 7
  • ptc_bricklet.FunctionSetResistanceCallbackThreshold = 9
  • ptc_bricklet.FunctionSetDebouncePeriod = 11
  • ptc_bricklet.FunctionSetNoiseRejectionFilter = 17
  • ptc_bricklet.FunctionSetWireMode = 20
  • ptc_bricklet.FunctionSetSensorConnectedCallbackConfiguration = 22
func (*PTCBricklet) 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

ptc_bricklet.DeviceIdentifier

This constant is used to identify a PTC 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.

ptc_bricklet.DeviceDisplayName

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