Dedicated driver for 7x11 LED matrixes?

• Dedicated driver for 7x11 LED matrixes?
  Posted by LinuxHata on 13 May, 2023 21:40
• Hello.
  There are a lot of 7X11 LED matrixes on the market. I bought couple of them, they have cathodes from 7x side and anodes from the 11x side. The question is, since such matrixes are made, there should be some dedicated circuitry to drive it?
  I know the mutliplexing options with transistors, I know about generic LED drivers like MAX7219, HT1632, TM1629A and so on. But all these are designed to drive LED matrixes in mutiple of 8 - like 8x8, 16x8, 32x16 and so on. Of course, these drivers can be also used for driving such LED matrixes, but a lot of outputs would be wasted. So maybe there is some dedicated chip for multiple 7x11 matrixes, about which I don't know?
  
• #1 Reply
  Posted by temperance on 13 May, 2023 21:47
• You can have a look at https://www.lumissil.com/home
• #2 Reply
  Posted by Benta on 13 May, 2023 21:51
• What exactly do you mean by "matrix"?
  Are we talking 7-segment, 11 digits here, or real 7 x 11 dot-matrix?
  
• #3 Reply
  Posted by LinuxHata on 14 May, 2023 05:25
• yes, 7 by 11 pixels led matrix.
  Mostly used in elevators in China.
  
• #4 Reply
  Posted by JustMeHere on 14 May, 2023 06:24
• Quote from: LinuxHata on 14 May, 2023 05:25

  yes, 7 by 11 pixels led matrix.
  Mostly used in elevators in China.
  

  
  Totally depends on how the device is driven.  You need to read the datasheet, or at least post a link to your product.
• #5 Reply
  Posted by LinuxHata on 14 May, 2023 06:34
• It is matrix of 7x11 LEDs.  They arranged in grid, cathodes go to 7 side, anodes go to 11 side.
  Have you seen 8x8 LED matrix? Exactly the same construction and arrangement, just instead of 8x8 grid, here is 7x11 grid. How can I explain any simpler?
  
  Here's quick example with pinout from google:
  
  https://lightkeyled.en.made-in-china.com/product/KCwEVfIrLMhs/China-RoHS-Compliant-2-2-Inch-7X11-Square-DOT-Matrix-Display-with-Pitch-5-7mm.html
• #6 Reply
  Posted by mariush on 14 May, 2023 06:53
• Yeah, Lumissil has a bunch of drivers that can n anodes , m cathodes  and some drivers that do matrixes, like 144 leds in a dot matrix.
  
  ex
  
  IS31FL3746B : https://www.digikey.com/en/products/detail/lumissil-microsystems/IS31FL3746B-QFLS4-TR/12675543
  18 current sinks
  Support 18×n (n=1~4) LED matrix configurations
  
  IS31FL3728 : https://www.digikey.com/en/products/detail/lumissil-microsystems/IS31FL3728-QFLS2-TR/5319755
  
  5~8 current source outputs for row control
  8~11 outputs for column scan control
  Programmable 8×8, 7×9, 6×10, 5×11 matrix
  
  IS31FL3729 : https://www.digikey.com/en/products/detail/lumissil-microsystems/IS31FL3729-QFLS4-TR/12675527
  16 current sinks
  Support 16×n (n=1~8), 15×9 LED matrix configurations
  
  and so on ...
  
  Even if there's no exact one that does  7x11, you could still treat it as two separate 5x11 matrixes or 2 4x18 for example, and just not use the extra anodes.
• #7 Reply
  Posted by LinuxHata on 14 May, 2023 18:46
• Yes I know all that, in fact, drivers I've mentioned are far more cheap than these.
  But the question is in another thing - how to find best matching driver.
  Best matching means less orphan pins and more leds driven with single chip.
  
  Say I want to drive as much of such modules as possible with a single chip. The best combo appears to be to wire chips in 22x14 matrix, which with 24x16 capable chip, such as HT1632C or similar, will leave 'only" unused 76 outputs, which I don't want to waste.
  
  So this is why I asked, maybe there is a dedicated solution for that specific arrangement.
  
• #8 Reply
  Posted by spostma on 15 May, 2023 16:59
• The low-cost drivers often cannot supply enough current to drive a display
  with many segments when you need to read the display in sunlight.
  
  if you have a 5V microcontroller with 11 tri-state spare outputs, then you could make a charlieplexing driver
  using 11 low-cost MMDT4413 NPN+PNP driver transistors and 11x 47R resistors on the common anodes or cathodes
  to get a cheap 100-150mA segment current driven at 1/11 duty cycle using a 1kHz timer interrupt.
• #9 Reply
  Posted by edavid on 15 May, 2023 19:26
• If you look on LCSC and filter on "13 segment by 7 bit", it comes up with 2 parts, AiP1612 and SM1628C.  Maybe worth a look?
  
• #10 Reply
  Posted by mariush on 15 May, 2023 19:37
• For the 11 anode, 7 cathode version you could probably use an ULN2003A  (7 darlingtons) on the cathodes.
  As for anodes, you could have mosfet or transistor arrays or shift registers to enable only particular anodes and cathodes (of course also current limiting resistors on each cathode) ... no led drivers involved
  
• #11 Reply
  Posted by LinuxHata on 18 Jun, 2023 15:06
• I finally found one - TM1623 and it's clones like AIP1623 and others
  Had a chance to look at elevator control board, so quickly "scanned" it for LED driver