Request: Reverse Row and Segments

[tekcreations]

I am using a Common Anode 16 segment LED 4 digit, I would love to use this library.
I have it working by sending setSegments(Digit number, Segment) so its reverse to normal, but I can't get a "font lookup table" working where I can use setdisplay to string.

Is this a possible enhancement?

[maxint-rd]

Hello @tekcreations ,

Which TM16xx chip are you using? Is it the TM1640? Are you using it on a commonly available display module or as stand-alone chip with your own wiring to connect the LED-display?

For the TM1638 there is a common anode module in the market called QYF-TM1638. For this module the TM1638QYF.h should be used, which takes care of the reversed setup. Since you mention 16 segments by four digits, can I presume you are using a different font to utilize that many segments to display different characters?

Perhaps you can take inspiration from the TM1638QYF.cpp code? In that implementation I've overloaded the setSegments method and used a memory bitmap prior to flipping the rows and columns when setting segments to display characters,

Although I do have plenty chips to experiment with, I currently don't have a 16-segment by 4 character display available. I did use the TM1640 chip, but only for driving LED-matrix displays. Do you have a link to AliExpress for the display that you are using? It would probably take a couple of months, but once I have them myself I could make an extension to the library.

[tekcreations]

Heya thanks for the reply. I am using a TM1640 with a common anode display similar to https://www.aliexpress.com/item/4000037229179.html I have gotten a "tiny" way..

The bare bones test code is below where i Specify the unit, this gives me a "G" on Both digits, "segment 11"

void sendascii(uint8_t n , uint8_t a, boolean d) { //uint16_t font = pgm_read_word(alphafonttable + a); uint16_t font = 0b0000000010111101; if (d) font |= (1 << 14);

for (int i = 15; i >= 0; --i) { if ((bool)(font & (1U << i))) { comdisp.setSegments(0b0000000000000011,i); }

My issue now is not sure how to "lookup" a char to get the Uint16. that pgm read I hacked from your code but doesnt seem to work. I'll have a look at the QYF and see if I can butcher that together somehow.

[tekcreations]

This is the wiring.

[maxint-rd]

Cool project. I think I'll also buy some to do some fun experiments. I see your display is 14+1 segments. On Ali I saw some 16+1 displays, but those exceed the TM1640 number of pins. Interesting to see how you are using the grid-lines to connect to the cathodes. I guess that each common anode is connected to one individual segment-line per character. Smart!

You seem to have accomplished already quite a bit. Well done! I think that what you need to do to fix reading the font is: pgm_read_word(alphafonttable + a*2); Since you are reading words (16-bit values) the font has two bytes per character. The address is a byte value and the offset for each character is therefor the character number times two.

Hope this helps. Good luck!

[maxint-rd]

Hello Kieron @tekcreations , it's been a while, but I finally found some time to work on the 5241BS 14+1 segment displays I ordered some time ago. Thanks again for the input and code you provided by e-mail last year. I hope you're doing well.

This week I published my take on this in the form of the TM1640Anode class and included further support for printing Ascii characters in TM16xxDisplay and the TM16xx base class. I intend to soon publish a new example that demonstrates the use of TM1640Anode combined with another module in a merged TM16xxDisplay object.