7segment

SA52-11EWA display 7segment

I have a quantity of green 7 segment displays labelled bd1-561 gu-a21.
leds-7-segment-displays
The pin sequence 7,6,4,2,1,9,10,5 is the sequence of the segments A,B,C,D,E,F,G,DP.
Note that 3 and 8 are missing, they are the common 'odes (cathode or anode).

521H 7 segment display is available in common cathode and common anode versions.
521h
Pins 3 and 8 are treated as connected together - the common pins.

Segment letters are enumerated clockwise from the top, G is the middle segment.
The display colour is red.
One current (active) project uses shift registers, 74HC595, to minimise the number of IO pins used on the micro-controller.