EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: onesixright on July 24, 2017, 10:48:34 am
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Anybody has a clue how you call this type of display? Its on ebay and aliexpress called a arge led display clock.
I'm only interested in the display. Any source to the display appreciated?
Thanks!
PS: to the moderator(s): isn't a separate section for component ID not handy?
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Closest would be an LED Matrix display with square pixels.
That one will be made from a custom plastic moulding, with individual 3mm PCB mounted LEDs mounted behind it.
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Particular display on the picture likely is a custom thing with a clock controller and bare die leds mounted on a single PCB.
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i think i'v seen those kits at banggood.
go look them up - see if it uses a standard microcontroller.
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It's a unique display with square pixels.
I have the smaller led matrix clock, 4-digit one with DS3231. The red LED's part number is MAX-13117BUR.
Oh I see it on Alibaba as KEM-13117 (http://dgkeming.en.alibaba.com/product/60318638276-214347137/common_anode_amber_11x7_led_matrix_square.html).
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*Square* is the keyword :-) Thanks!
Searching eBay for "square pixel matrix" a few hits. Also google "mini rgb square led" does wonders.
The "Adafruit DotStar" are very nice (multi color), but also very expensive. I need 2 or 3 horizontal >:(
I then ran into these, more affordable (less pretty).
https://www.seeedstudio.com/8x8-RGB-LED-Matrix-Square-LED-Dot-p-1730.html (https://www.seeedstudio.com/8x8-RGB-LED-Matrix-Square-LED-Dot-p-1730.html)
https://www.adafruit.com/product/902 (https://www.adafruit.com/product/902)
Not bad, but not h cheap.
https://www.aliexpress.com/item/apa102-addressable-led-mini-flexible-led-message-sign-board-screen/32797144408.html?spm=2114.search0302.4.2.wq1SUi (https://www.aliexpress.com/item/apa102-addressable-led-mini-flexible-led-message-sign-board-screen/32797144408.html?spm=2114.search0302.4.2.wq1SUi)
Thanks to all the help! :-+
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Can it display anything or is it just purpose built for a clock? If it's just a clock display, then it probably won't have pixels in places which will never be used when just displaying numbers.
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Many of those clock kits use a matrix of SMD LEDs, with a laser cut black acrylic sheet to form pixels, and simple paper or plastic sheet in front to diffuse. So it may not be a display module at all.
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Can it display anything or is it just purpose built for a clock? If it's just a clock display, then it probably won't have pixels in places which will never be used when just displaying numbers.
Wel each led you can switch on/off, so in essence you should be able to.
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Many of those clock kits use a matrix of SMD LEDs, with a laser cut black acrylic sheet to form pixels, and simple paper or plastic sheet in front to diffuse. So it may not be a display module at all.
Thats indeed exactly what it is. Bunch of LED's with a driver (often some MAXxxxx) with I2C support.
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stepping it up a notch
https://www.aliexpress.com/item/Factory-direct-sales-P6-indoor-1-8scan-SMD-full-color-192mm-192mm-32-32-pixels-27777dots/32373468927.html (https://www.aliexpress.com/item/Factory-direct-sales-P6-indoor-1-8scan-SMD-full-color-192mm-192mm-32-32-pixels-27777dots/32373468927.htm)
:-+
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I've got one of those somewhere. I'll see if I can find it and do a tear down.
I think it is just a bunch of SMD Leds.
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Can it display anything or is it just purpose built for a clock? If it's just a clock display, then it probably won't have pixels in places which will never be used when just displaying numbers.
Wel each led you can switch on/off, so in essence you should be able to.
What if it isn't a complete matrix? If it's designed for a clock and nothing else, then it's possible there are no LEDs where the pixels never will illuminate when displaying numbers, such as in the holes when the number 8 is displayed. The fact the picture in the original post shows an alarm symbol, indicates this is just a clock display.
It could be arranged as per my attachment. The areas with the dotted patten might not have any LEDs because they aren't needed for displaying numbers.
(https://www.eevblog.com/forum/chat/(id)-led-type-of-display/?action=dlattach;attach=335045;image)
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I've got one of these, and have just taken it apart.
The display isn't a full matrix - only the 7-segments of each digit, and the colon and am/pm & alarm indicators are populated with 3mm red leds.
The standard of construction is quite dreadful. There are two PCBs, with a mess of bodge wires and components tacked between tracks on both sides of the PCB. There's even a dropper resistor in line with the power connector, presumably to stop the voltage regulator overheating :palm:
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stepping it up a notch
https://www.aliexpress.com/item/Factory-direct-sales-P6-indoor-1-8scan-SMD-full-color-192mm-192mm-32-32-pixels-27777dots/32373468927.htm (https://www.aliexpress.com/item/Factory-direct-sales-P6-indoor-1-8scan-SMD-full-color-192mm-192mm-32-32-pixels-27777dots/32373468927.htm)
:-+
Speak of the devil! I just wired up the 64x32 RGB panel I got off Ali. (I got a P4, though, not P6.) Gonna have to try it on an arduino due, though, a Mega256 struggles to update it quickly!
P.S. Your URL got truncated, it's missing the L in .html
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I've got one of these, and have just taken it apart.
The display isn't a full matrix - only the 7-segments of each digit, and the colon and am/pm & alarm indicators are populated with 3mm red leds.
The standard of construction is quite dreadful. There are two PCBs, with a mess of bodge wires and components tacked between tracks on both sides of the PCB.
That's pretty much what I imagined would be inside it. Did you manage to re-purpose it?
There's even a dropper resistor in line with the power connector, presumably to stop the voltage regulator overheating :palm:
That's perfectly fine and is good design practise. A dropper resistor in series with a linear regulator is a fairly standard way to reduce the power dissipation in the IC. If there's a reasonable sized smoothing capacitor at the input of the regulator, it will also improve the ripple rejection too.