friend gave me a weird 7-segment display, and i'm keen to try to use it with arduino, but as i've not found a library for it, and it has 10 extra LED's embedded, i was wondering if anyone had any pointers on how exactly would i go about converting a standard library to utilize the extra LED's.
I've gone through with a multimeter, and mapped out the pins (1 - 13)
Here's an image of the module front & back, as well as the pin-map
What LED display driver IC are you planning to use? What Arduino do you have?
https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/679966/1#hardware
i have an uno, a mega, several nano's, soo, any of those would be fine.
I wouldn't think a driver IC would be required, but if so, i have a couple ICM722AIPIZ IC's, as well as several types of I2C IO expanders (mcp2317 16bit, pcf8574 8bit) or some 8bit shift register's
Of course you can drive a LED matrix from Arduino pins, using a library like:
https://github.com/sigvaldm/SevenSeg
but it uses up pins and requires that you run a service routine continuously. That can interfere with other devices, or other devices will interfere with it. Also with no display driver, you need current limiting resistors on the matrix.
I tried to Google ICM722AIPIZ and came up blank. What is it?
Hi,
What part number is printed on the side of the display?
Have you googled it?
Your display appears to be common Anode, so make sure any driver you choose can control a common anode display.
Tom.. 
Yes, I also want to know, for the reason that it's a cool display, I want one.
I tried googling the part number, but all i found was a few chinese sites trying to sell them (with no image or datasheet available)
The part number printed on the side is: HXDF-4047BHG-01
Apparently, you could use a MAX7219 to drive that display, even thought it's common anode and MAX7219s are presented as driving common cathode displays. There's an interesting article here:
I tried to Google ICM722AIPIZ and came up blank. What is it?[LED Display driver 8bit]
https://www.mouser.com/datasheet/2/698/IDT_icm7228_DST_19970212-1997708.pdf
Please edit your link, the post failed. Edit -thanks! If you already have those, why not use them?
Updated it
I agree with @markd833 - a max7219 would be a good way to drive this display. The code in the link posted should work for this display also.
Do not be concerned about the comments at the bottom of the linked page. They are incorrect, except those of 7SEGMENTFREAK which are correct.
Yes, those people have a hard time seeing the forest for the trees! It will definitely work.
Okay, well you have reverse engineered it and it looks like it is just an array of LEDs in common anode configuration.
I would say its RED LEDs, is it?
If so then calculate LED volt drop as 1.6V.
Current I would start at 20mA and see how bright they are.
As the display has a white frame, it would have been designed to operate with a red filter over the front.
Tom...
as i don't have a max7219 on hand, i instead used the ICM7228A i had, and a library i found on github... now to remap it to the device's pinout XD
I posted code in a thread about segment re-mapping. I wish I could locate it for you. But it's here on the forum fairly recently (few weeks ago?).
Hi,
Thanks for the video, Green and White LEDs, interesting.
Tom...
Seems obvious enough: Pins 1, 2, 4, and 5 are common anodes and pins 13, 12, 11, 9, 8, 7, and 6 are cathodes for the 7 A...G segments, as in a conventional 7segment display. The top 5 LEDs and the colon (7 LEDs total, again) have their anode on pin 3, and the bottom 5 LEDs are "8th segment" for each of the cathodes.
They are green segments, and red led's on the top and bottom.. the camera on my phone doesn't deal well with bright red LED's for some reason 
Well done for getting those working. The problem with them is the need for 10(?) Arduino pins. Max7219 needs only 3. Not so much of a problem if you are using Mega, but with Uno/Nano that would leave you with only a few pins left. I guess you could use pcf8574 to drive the 8 data lines, but then you would need to modify that library you found to use the pcf chip.
