Go - Solid State Relay Bricklet

This is the description of the Go API bindings for the Solid State Relay Bricklet. General information and technical specifications for the Solid State Relay 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/solid_state_relay_bricklet"
    "time"
)

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

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

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

    // Turn relay on/off 10 times with 1 second delay
    for i := 0; i < 5; i++ {
        time.Sleep(1000 * time.Millisecond)
        ssr.SetState(true)
        time.Sleep(1000 * time.Millisecond)
        ssr.SetState(false)
    }

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

API

The Solid State Relay Bricklet's API is defined in the package github.com/Tinkerforge/go-api-bindings/solid_state_relay_bricklet

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

  • BrickletErrorSuccess = 0
  • BrickletErrorInvalidParameter = 1
  • BrickletErrorFunctionNotSupported = 2
  • BrickletErrorUnknownError = 3

which correspond to the values returned from Bricks and Bricklets.

All functions listed below are thread-safe.

Basic Functions

func NewSolidStateRelayBricklet(uid string, ipcon *IPConnection)(device SolidStateRelayBricklet, err error)

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

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

func (*SolidStateRelayBricklet)SetState(state bool)(err error)

Sets the state of the relays true means on and false means off.

Running monoflop timers will be overwritten if this function is called.

The default value is false.

func (*SolidStateRelayBricklet)GetState()(state bool, err error)

Returns the state of the relay, true means on and false means off.

Advanced Functions

func (*SolidStateRelayBricklet)SetMonoflop(state bool, time uint32)(err error)

The first parameter is the desired state of the relay (true means on and false means off). The second parameter indicates the time (in ms) that the relay should hold the state.

If this function is called with the parameters (true, 1500): The relay will turn on and in 1.5s it will turn off again.

A monoflop can be used as a failsafe mechanism. For example: Lets assume you have a RS485 bus and a Solid State Relay Bricklet connected to one of the slave stacks. You can now call this function every second, with a time parameter of two seconds. The relay will be on all the time. If now the RS485 connection is lost, the relay will turn off in at most two seconds.

func (*SolidStateRelayBricklet)GetMonoflop()(state bool, time uint32, timeRemaining uint32, err error)

Returns the current state and the time as set by (*SolidStateRelayBricklet) SetMonoflop as well as the remaining time until the state flips.

If the timer is not running currently, the remaining time will be returned as 0.

func (*SolidStateRelayBricklet)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 (*SolidStateRelayBricklet)GetResponseExpected(functionId uint8)(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 (*SolidStateRelayBricklet) 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 (*SolidStateRelayBricklet) SetResponseExpected for the list of function ID constants available for this function.

func (*SolidStateRelayBricklet)SetResponseExpected(functionId uint8, 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 function ID constants are available for this function:

  • FunctionSetState = 1
  • FunctionSetMonoflop = 3
func (*SolidStateRelayBricklet)SetResponseExpectedAll(responseExpected bool)(err error)

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

func (*SolidStateRelayBricklet)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

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 (*SolidStateRelayBricklet)RegisterMonoflopDoneCallback(func(state bool))(callbackID uint64)

A callback can be registered for this event with the RegisterMonoflopDoneCallback() function. This function returns the ID of the registered callback. An added callback can be removed with the DeregisterMonoflopDoneCallback(callbackID uint64) function.

This callback is triggered whenever the monoflop timer reaches 0. The parameter is the current state of the relay (the state after the monoflop).

Constants

solid_state_relay_bricklet.DeviceIdentifier

This constant is used to identify a Solid State Relay Bricklet.

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

solid_state_relay_bricklet.DeviceDisplayName

This constant represents the human readable name of a Solid State Relay Bricklet.