I recently bought an led clock kit from a Chinese company. The intriguing thing is the multicolour 4digit 7segmrnt display. The clock can display a range of colours. The display has only 5 or 6 pins.
My question is this:-, does anyone have knowledge of this display and how to implement it with an Arduino. The company is Banggood but the display had no marked part number. The display is a glorious 2.5 cm high.
Peter Alley
It probably uses something like this
so you are looking at reverse engineering whatever communication method is being used to inform the color of N number of single RGB LEDs.
I would guess, if forced, probably not smart pixels, probably not I2C, so you need to run the device it is build into, and start looking for data and clock signals you can make sense of.
Please post well focus pictures of the front and back of this unit.
I couldn't find anything like it for sale, multicolor just keeps turning up displays available in a multitude of colors, red, yellow &c.
Post a link to B*ngG**d where they sell it.
a7
Is it this one?
You afraid of saying "Banggood"?
If so, it looks like smart LEDs, but tightly integrated with the processor, so using it otherwise might be a challenge.
Sometimes on prebuilt stuff like that you can find an ICSP interface and see that it’s an AVR processor and put your own code on it.
I can see a DS3231 RTC on there, the other chip is prolly the microprocessor.
From the instructions
Please read the entire production process
carefully and then do it better.
LOL!
a7
The kit is this one.. See link.
It was only about ÂŁ6 -ÂŁ7. I don't like to advertise product or companies but am intrigued by what could be a very useful display.
A single display showing multiple variables in turn each in a different colour and a nice size too
The display is a 4 digit one in one housing. There are actually 8 pins . The clock circuit is a standard (for Ardy Annuals) DS1302. The controller is marked 15W4**AS.
As I stated, there are no markings on the display itself that I could trace online.
As was suggested perhaps I need to do some investigatory reverse engineering but then need to find a supply for the display.
Cheers all
The kit is this one.. See link.
See no functioning link, so.
In any case, a source for that display, if you only talking about picking up a few for fun not building 2000 whatevers, is to buy the kit and use the part(s) you want…
Wasteful, but I guarantee you would not be the first to do, you would def be the second. At least. 
If you are producing 1000s, then it starts to makes sense to design the display from scratch.
a7
I agree about possibly buying the kits for parts. They are cheap enough. However, I do like to make my projects reproducible in the future.
In the previous post added an image, albeit a tiny one of the kit.
The Banggood kit is billed as:-
I attach a screenshot of the kit.
No, like real link…
a7
The display looks like it's SDI, so it may be possible to find the display datasheet and drive it with an Arduino.
I ordered one.
http://www.diyleyuan.com/jc/201C/Installation%20tutorial%20of%20seven%20color%20digital%20clock%20CAI-201.pdf
Why don't check kits datasheets?
Are you aiming to learn reverse engineering techniques?
Ah, I thought of that, but alas the kit does not have a data sheet nor could I find one. A bunch of components, a well labelled PCB and a setting menu for the completed mostly in Chinese is what I had to work with. Hence my reaching out on the forum.
Thank you for finding the information sheet you attached. Makes for easier setting.
I now would like to know how to drive the display using an Arduino .
Thankyou.
I opened described link and found at the silked products number at the bottom left of the PCB.
I googled it, something like a datasheet was displayed at first results and I was open that.
And simpley checked the integrity of the some components.
I was convinced that it has described this kit.
I think it took less than 30 seconds.
Thank you Chris. That puts me well on the track of my goal.
I now need to understand SDI style interfacing and how it works with this display.
Thanks again
Looks like D0 and D1 select the digit (0-3) while LE (Load Enable?) , SDI (Serial Data In), and CLK (Clock) load two 16-bit shift registers for the three sets of 8 segments (7 + decimal point). The remaining 8 bits aren't used.
You are welcome. 
This RGB 7-segment LED module made for this kit is quite interesting.
The IC installed for drive each LED segments also looks good specifications.
I can think various uses for many project...
I wondering should buy too. 
You can use it freely if you investigate the drive method of the LED called "multiplexing" and the operate shift register.
Looks the same as SPI but without using MISO (outbound data only).
MOSI -> SDI
SS/CS -> LE
SCL -> CLK
Remember to send three bytes of 0 to turn off all 24 LEDs before changing the digit select pins, otherwise you will get ghosting because the lit segments will show up on the new digit before the new segments can be loaded.
I think it's better to do the blanking using the EN pin connected to the Enable of the anode driver SM5166P.
Good point. I forgot that pin.
Please share your project when you get the display working with the Arduino.
