Go - OLED 64x48 Bricklet

This is the description of the Go API bindings for the OLED 64x48 Bricklet. General information and technical specifications for the OLED 64x48 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).

Hello World

Download (example_hello_world.go)

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package main

import (
    "fmt"
    "github.com/Tinkerforge/go-api-bindings/ipconnection"
    "github.com/Tinkerforge/go-api-bindings/oled_64x48_bricklet"
)

const ADDR string = "localhost:4223"
const UID string = "XYZ" // Change XYZ to the UID of your OLED 64x48 Bricklet.

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    oled, _ := oled_64x48_bricklet.New(UID, &ipcon) // Create device object.

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

    // Clear display
    oled.ClearDisplay()

    // Write "Hello World" starting from upper left corner of the screen
    oled.WriteLine(0, 0, "Hello World")

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

Pixel Matrix

Download (example_pixel_matrix.go)

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package main

import (
    "fmt"
    "github.com/Tinkerforge/go-api-bindings/ipconnection"
    "github.com/Tinkerforge/go-api-bindings/oled_64x48_bricklet"
)

const ADDR string = "localhost:4223"
const UID string = "XYZ" // Change XYZ to the UID of your OLED 64x48 Bricklet.

const WIDTH = 64
const HEIGHT = 48

func drawMatrix(oled oled_64x48_bricklet.OLED64x48Bricklet, pixels [HEIGHT][WIDTH]bool) {
    var pages [HEIGHT / 8][WIDTH]uint8
    for colIdx, col := range pages {
        for rowIdx := range col {
            for bit := 0; bit < 8; bit++ {
                if pixels[colIdx*8+bit][rowIdx] {
                    pages[colIdx][rowIdx] |= 1 << uint(bit)
                }
            }
        }
    }

    oled.NewWindow(0, WIDTH-1, 0, (HEIGHT/8)-1)

    for row := 0; row < HEIGHT/8; row++ {
        oled.Write(pages[row])
    }
}

func main() {
    ipcon := ipconnection.New()
    defer ipcon.Close()
    oled, _ := oled_64x48_bricklet.New(UID, &ipcon) // Create device object.

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

    // Clear display
    oled.ClearDisplay()

    // Draw checkerboard pattern
    var pixels [HEIGHT][WIDTH]bool
    for rowIdx, row := range pixels {
        for colIdx := range row {
            pixels[rowIdx][colIdx] = (rowIdx/8)%2 == (colIdx/8)%2
        }
    }

    drawMatrix(oled, pixels)

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

API

The OLED 64x48 Bricklet API is defined in the package github.com/Tinkerforge/go-api-bindings/oled_64x48_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 NewOLED64x48Bricklet(uid string, ipcon *IPConnection) (device OLED64x48Bricklet, err error)

Creates a new OLED64x48Bricklet object with the unique device ID uid and adds it to the IPConnection ipcon:

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

func (*OLED64x48Bricklet) Write(data [64]uint8) (err error)

Appends 64 byte of data to the window as set by NewWindow().

Each row has a height of 8 pixels which corresponds to one byte of data.

Example: if you call NewWindow() with column from 0 to 63 and row from 0 to 5 (the whole display) each call of Write() (red arrow) will write one row.

Display pixel order

The LSB (D0) of each data byte is at the top and the MSB (D7) is at the bottom of the row.

The next call of Write() will write the second row and so on. To fill the whole display you need to call Write() 6 times.

func (*OLED64x48Bricklet) NewWindow(columnFrom uint8, columnTo uint8, rowFrom uint8, rowTo uint8) (err error)

Sets the window in which you can write with Write(). One row has a height of 8 pixels.

The columns have a range of 0 to 63 and the rows have a range of 0 to 5.

func (*OLED64x48Bricklet) ClearDisplay() (err error)

Clears the current content of the window as set by NewWindow().

func (*OLED64x48Bricklet) WriteLine(line uint8, position uint8, text string) (err error)

Writes text to a specific line (0 to 5) with a specific position (0 to 12). The text can have a maximum of 13 characters.

For example: (1, 4, "Hello") will write Hello in the middle of the second line of the display.

You can draw to the display with Write() and then add text to it afterwards.

The display uses a special 5x7 pixel charset. You can view the characters of the charset in Brick Viewer.

Advanced Functions

func (*OLED64x48Bricklet) SetDisplayConfiguration(contrast uint8, invert bool) (err error)

Sets the configuration of the display.

You can set a contrast value from 0 to 255 and you can invert the color (black/white) of the display.

The default values are contrast 143 and inverting off.

func (*OLED64x48Bricklet) GetDisplayConfiguration() (contrast uint8, invert bool, err error)

Returns the configuration as set by SetDisplayConfiguration().

func (*OLED64x48Bricklet) 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 (*OLED64x48Bricklet) 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 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.

func (*OLED64x48Bricklet) 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:

  • FunctionWrite = 1
  • FunctionNewWindow = 2
  • FunctionClearDisplay = 3
  • FunctionSetDisplayConfiguration = 4
  • FunctionWriteLine = 6
func (*OLED64x48Bricklet) SetResponseExpectedAll(responseExpected bool) (err error)

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

func (*OLED64x48Bricklet) 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.

Constants

oled_64x48_bricklet.DeviceIdentifier

This constant is used to identify a OLED 64x48 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.

oled_64x48_bricklet.DeviceDisplayName

This constant represents the human readable name of a OLED 64x48 Bricklet.