TM1637 - Segment Display

TM1637 is a segments display with 6 characters Led controler. It uses a 2 wire implementation, one for the clock (CLK), one for the data (DIO). This chip can act as well as a key reader. This part has not been implemented. Only the Led display has been implemented. Most of its modern usages are for 4 to 6 segment displays.

Documentation

• TM1637 datasheet

Device family

You can find this display as Grove elements as well as very cheap with no brand. A search on your favorite online shop will give you lots of options. Those simple displays are used a lot for simple clock for example.

Testing was performed with a HiLetgo part.

Usage

You need to create a Tm1637 class with 2 pins, the clock one and the data one.

Tm1637 tm1637 = new Tm1637(4, 0);

Screen on, off, brightness

It is possible and you have to turn the screen on when you want to use the Tm1637.

tm1637.Brightness = 7;
tm1637.ScreenOn = true;
tm1637.ClearDisplay();

As an example, this will blink the screen:

for (int i = 0; i < 10; i++)
{
    tm1637.ScreenOn = !tm1637.ScreenOn;
    tm1637.Display(rawData);
    Thread.Sleep(500);
}

When adjusting the screen brightness from 0 to 7 where 7 is the maximum, the command is immediate.

You can clear the display as well:

tm1637.ClearDisplay();

Displaying pre build characters

Characters are prebuild from 0 to F to facilitate hexadecimal displays on the segments. The following example will display the number 4 then 2 with a dot then A and F.

Character[] toDisplay = new Character[4] {
    Character.Digit4,
    Character.Digit2 | Character.Dot,
    Character.Digit3,
    Character.Digit8
};
tm1637.Display(toDisplay);

The maximum size of the buffer is 6.

Displaying raw data

You can as well display raw data like in the following example:

// Displays couple of raw data
Character[] rawData = new Character[6] {
    // All led on including the dot
    (Character)0b1111_1111, 
    // All led off
    (Character)0b0000_0000,
    // top blanck, right on, turning like this including dot
    (Character)0b1010_1010,
    // top on, right black, turning like this no dot
    (Character)0b0101_0101,
    // half one half off
    Character.SegmentTop | Character.SegmentTopRight | Character.SegmentBottomRight | Character.SegmentBottom, 
    // half off half on
    Character.SegmentTopLeft|Character.SegmentBottomLeft|Character.SegmentMiddle | Character.Dot,
};
// If you have a 4 display, only the first 4 will be displayed
// on a 6 segment one, all 6 will be displayed
tm1637.Display(rawData);

The maximum size of the buffer is 6.

Segment order

You can change the order of the characters. In some cases, especially when you have displays with 6 segments split with 2 displays of 3, the order may not be the one you expect.

tm1637.CharacterOrder = new byte[] { 2, 1, 0, 5, 4, 3 };

Make sure you have a length of 6 and all numbers from 0 to 5.