Rust - Segment Display 4x7 Bricklet

This is the description of the Rust API bindings for the Segment Display 4x7 Bricklet. General information and technical specifications for the Segment Display 4x7 Bricklet are summarized in its hardware description.

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


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


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use std::{error::Error, io};

use tinkerforge::{ip_connection::IpConnection, segment_display_4x7_bricklet::*};

const HOST: &str = "";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your Segment Display 4x7 Bricklet

const DIGITS: [u8; 16] = [0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f, 0x77, 0x7c, 0x39, 0x5e, 0x79, 0x71]; // 0~9,A,b,C,d,E,F

fn main() -> Result<(), Box<dyn Error>> {
    let ipcon = IpConnection::new(); // Create IP connection
    let sd = SegmentDisplay4x7Bricklet::new(UID, &ipcon); // Create device object

    ipcon.connect((HOST, PORT)).recv()??; // Connect to brickd
                                          // Don't use device before ipcon is connected

    // Write "4223" to the display with full brightness without colon
    let segments = [DIGITS[4], DIGITS[2], DIGITS[2], DIGITS[3]];
    sd.set_segments(segments, 7, false);

    println!("Press enter to exit.");
    let mut _input = String::new();
    io::stdin().read_line(&mut _input)?;


To allow non-blocking usage, nearly every function of the Rust bindings returns a wrapper around a mpsc::Receiver. To block until the function has finished and get your result, call one of the receiver's recv variants. Those return either the result sent by the device, or any error occured.

Functions returning a result directly will block until the device has finished processing the request.

All functions listed below are thread-safe, those which return a receiver are lock-free.

Basic Functions

pub fn SegmentDisplay4x7Bricklet::new(uid: &str, ip_connection: &IpConnection) → SegmentDisplay4x7Bricklet

Creates a new SegmentDisplay4x7Bricklet 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).

pub fn SegmentDisplay4x7Bricklet::set_segments(&self, segments: [u8; 4], brightness: u8, colon: bool) → ConvertingReceiver<()>

The 7-segment display can be set with bitmaps. Every bit controls one segment:

Bit order of one segment

For example to set a "5" you would want to activate segments 0, 2, 3, 5 and 6. This is represented by the number 0b01101101 = 0x6d = 109.

The brightness can be set between 0 (dark) and 7 (bright). The colon parameter turns the colon of the display on or off.

pub fn SegmentDisplay4x7Bricklet::get_segments(&self) → ConvertingReceiver<Segments>

Returns the segment, brightness and color data as set by SegmentDisplay4x7Bricklet::set_segments.

Advanced Functions

pub fn SegmentDisplay4x7Bricklet::start_counter(&self, value_from: i16, value_to: i16, increment: i16, length: u32) → ConvertingReceiver<()>

Starts a counter with the from value that counts to the to value with the each step incremented by increment. The length of the increment is given in ms.

Example: If you set from to 0, to to 100, increment to 1 and length to 1000, a counter that goes from 0 to 100 with one second pause between each increment will be started.

The maximum values for from, to and increment is 9999, the minimum value is -999.

Using a negative increment allows to count backwards.

You can stop the counter at every time by calling SegmentDisplay4x7Bricklet::set_segments.

pub fn SegmentDisplay4x7Bricklet::get_counter_value(&self) → ConvertingReceiver<u16>

Returns the counter value that is currently shown on the display.

If there is no counter running a 0 will be returned.

pub fn SegmentDisplay4x7Bricklet::get_api_version(&self) → [u8; 3]

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.

pub fn SegmentDisplay4x7Bricklet::get_response_expected(&mut self, function_id: u8) → bool

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 SegmentDisplay4x7Bricklet::set_response_expected. 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 SegmentDisplay4x7Bricklet::set_response_expected for the list of function ID constants available for this function.

pub fn SegmentDisplay4x7Bricklet::set_response_expected(&mut self, function_id: u8, response_expected: bool) → ()

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:

pub fn SegmentDisplay4x7Bricklet::set_response_expected_all(&mut self, response_expected: bool) → ()

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

pub fn SegmentDisplay4x7Bricklet::get_identity(&self) → ConvertingReceiver<Identity>

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.


Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding get_*_callback_receiver function, which returns a receiver for callback events.


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.

pub fn SegmentDisplay4x7Bricklet::get_counter_finished_callback_receiver(&self) → ConvertingCallbackReceiver<()>

Receivers created with this function receive Counter Finished events.

This callback is triggered when the counter (see SegmentDisplay4x7Bricklet::start_counter) is finished.



This constant is used to identify a Segment Display 4x7 Bricklet.

The SegmentDisplay4x7Bricklet::get_identity function and the IpConnection::get_enumerate_callback_receiver callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.


This constant represents the human readable name of a Segment Display 4x7 Bricklet.