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Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Without data sheets for LED displays I have determined which pin is which using this method. Set my adjustable power supply to 5V. Put a 330 ohm resistor in series with either + or - lead. Connect the lead without the resistor to one pin. Connect the resistor end of the other lead to each other pin one at a time and see which segment lights up. If none do switch the resistor to the other lead and repeat the process. They are either common anode, or common cathode. If they are common anode a postive on a pin and moving the resistor to different pins different segments light up. They are common cathode if a negative on a pin and moving the resistor to different pins lights up different segments. If more than on segment lits when moving the resistor then they are multiplexed.
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