[Answered] TM1628 example??

[Dancopy]

Greetings.
How do I test a TM1628 Display, as there is no example code? I opened 'TM16xx setSegments example' and added '#include <TM1628.h>
TM1628 module(8, 9, 7);' to the header, but it doesn't accept the functions in the example. It shows the following error: 'class TM1628' has no member named 'setDisplayToString'.
Any tips on how to use these examples in the TM1628 Display?

Thank you,

Daniel Fernandes

[maxint-rd]

Hello Daniel , thank you for submitting this issue. I have the TM1628 in my collection and have tested the TM1628 class myself, so all examples should work (unless I made a mistake), so let's figure out what's wrong...
(I hope you have some time to play along and try things out).

To do some virtual testing I've used the Wokwi simulator. Since there is no TM1628 chip in Wokwi (yet), I simply connected an RGB LED to have some visualization.
Please have a look at my test of the example on Wokwi.

On top of the code in Wokwi, you can see I first tried the example shown in the readme page. When that worked I tried the TM16xx setSegments example. It gave much better color variations in the LED...

it shows the following error: 'class TM1628' has no member named 'setDisplayToString'.

This makes me think something might be conflicting in your environment,
Could it be that you have a different TM16XX library installed that also has a TM16xx,h header file?

Please note that the TM1628 class is derived from the TM16xx class. The TM1628.h includes TM16xx.h to get the definition of the TM16xx class.

That class implement the function as follows:
virtual void setDisplayToString(const char* string, const word dots=0, const byte pos=0, const byte font[] = TM16XX_FONT_DEFAULT);
You can find documentation of that function in the base class reference.

Another possibility is that you changed the example a bit. Note that the first parameter of setDisplayToString() is a pointer to a character array, not to a String object. If you're using a String object, you can use the print() function that is implemented in the TM16xxDisplay class. See also this example.

[Dancopy]

Hello, First of all, thank you very much for replying. But, before running the code you sent me, I have another question: My display with the TM1628 driver is 4 digits, and the display pins (12) are already all connected (distributed) to the driver (TM1628), so how does the program, through the sketch, understand this? Because there is no pin allocation in the sketch. In fact, most of the sketches I've seen are quite complicated. For example, this one: https://github.com/emsyscode/SM1628B/blob/master/SM1628B_display_7Segments_DVD.cpp. My board (photo attached), in addition to the display, has 4 push buttons. With this, I would like to make a clock, but I'm a little far from that. Once again, thank you, Daniel

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________________________________ De: Maxint R&D ***@***.***> Enviado: quarta-feira, 19 de novembro de 2025 18:51 Para: maxint-rd/TM16xx ***@***.***> Cc: Dancopy ***@***.***>; Author ***@***.***> Assunto: Re: [maxint-rd/TM16xx] TM1628 Code?? (Issue #69) [https://avatars.githubusercontent.com/u/22682220?s=20&v=4]maxint-rd left a comment (maxint-rd/TM16xx#69)<#69 (comment)> Hello Daniel , thank you for submitting this issue. I have the TM1628 in my collection and have tested the TM1628 class myself, so all examples should work (unless I made a mistake), so let's figure out what's wrong... (I hope you have some time to play along and try things out). To do some virtual testing I've used the Wokwi simulator. Since there is no TM1628 chip in Wokwi (yet), I simply connected an RGB LED to have some visualization. Please have a look at my test of the example on Wokwi<https://wokwi.com/projects/448084913544294401>. On top of the code in Wokwi, you can see I first tried the example shown in the readme<https://github.com/maxint-rd/TM16xx#base-class-usage-tm1637-tm1638-tm16> page. When that worked I tried the TM16xx setSegments example. It gave much better color variations in the LED... it shows the following error: 'class TM1628' has no member named 'setDisplayToString'. This makes me think something might be conflicting in your environment, Could it be that you have a different TM16XX library installed that also has a TM16xx,h header file? Please note that the TM1628 class is derived from the TM16xx class. The TM1628.h includes TM16xx.h to get the definition of the TM16xx class. That class implement the function as follows: virtual void setDisplayToString(const char* string, const word dots=0, const byte pos=0, const byte font[] = TM16XX_FONT_DEFAULT); You can find documentation of that function in the base class reference<https://github.com/maxint-rd/TM16xx/wiki/TM16xx-base-class-reference#setdisplaytostringconst-char-string-const-word-dots0-const-byte-pos0-const-byte-font--tm16xx_font_default>. Another possibility is that you changed the example a bit. Note that the first parameter of setDisplayToString() is a pointer to a character array, not to a String object. If you're using a String object, you can use the print()<https://github.com/maxint-rd/TM16xx/wiki/TM16xxDisplay-class-reference#print> function that is implemented in the TM16xxDisplay class<https://github.com/maxint-rd/TM16xx?tab=readme-ov-file#tm16xxdisplay-class>. See also this example<https://github.com/maxint-rd/TM16xx/blob/master/examples/TM16xxDisplay_Print/TM16xxDisplay_Print.ino>. — Reply to this email directly, view it on GitHub<#69 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AJBBERYXMFQSXGOJN6CLIHD35TQ6NAVCNFSM6AAAAACMTSX5RGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTKNJUG43DSNJVHA>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[maxint-rd]

Hello again,

Because there is no pin allocation in the sketch. In fact, most of the sketches I've seen are quite complicated.

But there is... It is on top of the sketch:

#include <TM1628.h>

TM1628 module(8, 9, 7);   // DIO=8, CLK=9, STB=7

These three pins in the constructor tell the library how to send data to the TM1628 chip via a serial connection over the Arduino pins. The TM1628 then drives the 12 wires to the display to light up the LEDs.

So using these three pins, the library code knows how to send a serial data stream to the TM1628 chip whenever something needs to be displayed. It writes control codes as well as display data. All the complicated code you see in the SM1628B example is embedded in various parts of the library. If you're interested, you can review the cpp files in the SRC folder. In the readme you can read more about the structure of the library.

Note that the example on Wokwi is a live demo on a virtual processor. You don't need to run or compile anything on your computer. Just follow the link and hit the play button. Perhaps you also like this Wokwi demo, featuring a 4-digit TM1637 display module.

[Dancopy]

Hello friend! Regarding the error that was showing: 'class TM1628' has no member named 'setDisplayToString', it disappeared after I uninstalled the TM1628 library, which conflicted with your TM16xx. I only have one more question, please: do these codes (Arduino) for the clock, using the TM1637 driver, also work for the TM1628? I ask this because these are much easier to find on the internet. Thank you very much for the explanations.

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________________________________ De: Maxint R&D ***@***.***> Enviado: sexta-feira, 21 de novembro de 2025 08:33 Para: maxint-rd/TM16xx ***@***.***> Cc: Dancopy ***@***.***>; Author ***@***.***> Assunto: Re: [maxint-rd/TM16xx] TM1628 Code?? (Issue #69) [https://avatars.githubusercontent.com/u/22682220?s=20&v=4]maxint-rd left a comment (maxint-rd/TM16xx#69)<#69 (comment)> Hello again, Because there is no pin allocation in the sketch. In fact, most of the sketches I've seen are quite complicated. But there is... It is on top of the sketch: #include <TM1628.h> TM1628 module(8, 9, 7); // DIO=8, CLK=9, STB=7 These three pins in the constructor tell the library how to send data to the TM1628 chip via a serial connection over the Arduino pins. The TM1628 then drives the 12 wires to the display to light up the LEDs. So using these three pins, the library code knows how to send a serial data stream to the TM1628 chip whenever something needs to be displayed. It writes control codes as well as display data. All the complicated code you see in the SM1628B example is embedded in various parts of the library. If you're interested, you can review the cpp files in the SRC folder<https://github.com/maxint-rd/TM16xx/tree/master/src>. In the readme you can read more about the structure of the library<https://github.com/maxint-rd/TM16xx?tab=readme-ov-file#library-structure>. Note that the example on Wokwi<https://wokwi.com/projects/448084913544294401> is a live demo on a virtual processor. You don't need to run or compile anything on your computer. Just follow the link and hit the play button. Perhaps you also like this Wokwi demo<https://wokwi.com/projects/361918908322950145>, featuring a 4-digit TM1637 display module. — Reply to this email directly, view it on GitHub<#69 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AJBBER2BA7WERI5GCKBXDD3353Z7DAVCNFSM6AAAAACMTSX5RGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTKNRSGYZDQNBRGY>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[maxint-rd]

What codes for what clock are you referring to? I don't see what you mean.

Do the library examples now work on your display?

[Dancopy]

Hello again, friend. I'll go step by step.

1. Regarding the clock, it would be a code for a clock with 2 or 3 buttons to adjust the time, like this one, for example: https://akuzechie.blogspot.com/2021/02/real-time-clock-using-tm1637-ds3231.html.
2. About the example you sent me (wokwi.com), on my display, which has 4 digits + symbols, it starts by lighting up (from right to left) the digits 1, 2, 3, 4, and then the symbols (MP4, MP3, Arrow, Pause). It stays on for about 10 seconds and starts again. But, the digits of the numbers light up missing the segment of the letter "C" in all 4 digits, as shown in the image I attached.

Thank you again.

[Dancopy]

P.S.: Wouldn't it be possible to use the same code (Clock) from the TM1637 for the TM1628, using its library, with two buttons or a remote control?

[maxint-rd]

Thank you for including those pictures. It makes it easier to understand what you are working with. I now see you want to make a clock out of an old display module taken from a DVD player.

Your test seems to indicate that the wiring of that module from the TM1628 to the LED segments uses more than 8 segments and doesn't follow the standard order (A=segment 1, B=segment 2, etc.).

In this table you can see that the TM1628 supports driving up to 13 segments. You need to figure out what segment output is connected to what LED display. (The digit order may be non-standard as well). You probably need to do much more testing so find things out.

Next test you can do is modify the SetSegments example to use more than 8 segments. Just now I've modified the example on Wokwi so that it addresses 4 digits and up to 16-segments using the setSegments16() function. Feel free to try that code to see if the C segment now lights up. Try to understand what changes I made and then try the SetSegmentsDebug example to document the precise connections of the SEG/GRD pins to your LED display.

Can you also post a picture of the other side of the PCB?

P.S.: Wouldn't it be possible to use the same code (Clock) from the TM1637 for the TM1628, using its library, with two buttons or a remote control?

Yes. If you have working code for the TM1637, the abstraction feature of the library makes it possible to use the same code on the TM1628. It would only require minimal tweaks to make up for the differences, such as the fact that TM1628 uses three control lines and TM1637 only uses two lines.

[Dancopy]

Hello friend! I don't want to bother you, but I see you want to help me, so I'm sending you a photo and video for you to check.

1. The change you made to the Wokwi code didn't change much, as you will see from the attached video.
2. I attached a photo of the back of the PCB and a schematic of the display pins with the HT1628 and the buttons.

Video_1.mp4

3. Regarding using the TM1637 code (clock) with the TM1628, I didn't understand how to do it.

My sincere thanks.

[Dancopy]

Hello friend.
Updating the schematic, there are 5 Grids, with Grid 5 (G5) being the first Digit from right to left.