IEE 3785R dual 14 segment LED pinout

It's also Kingbright part number PDA54-12GWA here's the spec sheet for a green one, same schematic 

These dual character 14 segment 0.54" displays all LOOK similar but ELECTRICALLY they're very different!

leftmost: 5241BS white segments on black bezel:
common anode per character


center: IEE 3785R white segments on grey bezel:
Instead of a common cathode per character, they're divided diagonally into 7 segments per common
so an 8x8 matrix driver chip (such as the Maxim 7219) drives 4 characters with decimal points.


right: LiteOn LTM 8647AP red segments on black bezel:
has an embedded M5450 controller chip!

This is a typical dual character 14 segment LED module:
14 leds + decimal point for 15 leds to a common cathode or anode.
The Holtek HT16k33 LED controller directly drives 16 anodes by 8 cathodes.
Common anode LED module? No such luck.
graphical pinout by HarveyH42

The IEE 3785R dual 14 segment red LED module divides each character diagonally
resulting in 2 common cathodes by 7 anodes (instead of the usual single common cathode by 14 anodes).
The dual character module is electrically 4 common cathodes by 7 segment anodes (plus decimal point).
A common LED controller such as the Maxim 7219/7221 handles 4 such characters (2 dual character modules) as an 8x8 LED matrix. 

______A______
|F \H |I /J |B
__G1__ __G2__
|E /M |L \K |C
______D______   .dp (decimal point)

IEE 3785 pinout

common cathode: pin 1 pin 3 pin 4 pin 6 pin 9 pin 12 pin 14 pin 17 pin 18
pin 5
left char 		G2 K C dp - D B L J
pin 15
left char 		G1 M E - - A F I H
pin 10
right char 		G2 K C - dp D B L J
pin 8
right char 		G1 M E - - A F I H
The segments are named as per this data sheet for teeny 16 segment LED modules
I guess I can connect pin 6 to 9 to use an 8x8 controller to get both decimal points.

electro-tech-online.com/threads/dual-led-alphanumeric-display.35774 discussed this display module in 2008


blueroomelectronics notes "Treat them like a 4 digit common cathode display"
so an 8x8 matrix driver chip (such as the Maxim 7219) will drive 4 characters with decimal points.

aries1470 added these specs: 
LR3785R
Industrial Electronic Engineers :: Segmented Alphanumeric LED Display - (8.8.)
Specsheet / Datasheet
Package Style (Basic)=2-Edge
Number of Characters=2
Connection Type=Comm Cath.
Color=Red
Character Height (mm)=14
Peak Wavelength (m)=655n
Iv Min.(cd) Luminous Intensity=250u
@I(F) (A) (Test Condition)=20m
V(F) Max.(V) Forward Voltage=2.0
@I(F) (A) (Test Condition)=20m
I(F) Max. (A) Forward Current=25m
Package=2-Edge

justDIY notes that IEE [the display company] was purchased by Fairchild,
who dumped their opto division and removed all data sheets from their website.
Here's a video by a clever fellow
16-segment font an HDSP-6508 LED display
Uploaded by 74hc595 on Sep 23, 2009
Here's a full ASCII font (upper and lowercase) that I designed for old HDSP-6508 sixteen-segment "starburst" displays.
More info at http://www.msarnoff.org/projects/alpha32/