I have been given a number of 7x5 dot matrix display segments. There are 7
pins at the top and 7 at the bottom. The ID on the segment is:
927 TAIWAN P
Can someone be kind enough to explain the pin-out for me.
Connect 3 to 5 volts (through a current-limiting
resistor), negative to one cathode, positive to
each anode in turn; each time a different spot
should come on. Move neg. to the next cathode,
then pos. to each anode again - different spots
Choose the resistor value to limit current to
25mA. As the small schematic in the doc with all
the diodes shows, they're arranged in a row-col
Hi, Roger. Driving the displays you have might not be the easiest
thing for a newbie. They work on the time multiplexing principle. If
you apply 7 bits of data to the anode pins, and then activate one of
the cathode pins, one row of the diplay will light. By using a
computer or microcontroller amd appropriate high current latching
drivers, you can scroll across the rows at a fast rate (say, 1000
times a second or so), and due to persistence of vision it will appear
that all the rows are on at once. A typical microcontroller can
easily handle this and also take care of other things such as
maintaining a communications link and taking care of other business.
But unless you've got that microcontroller, it is going to be really
difficult to get a whole lot of use out of your display.
Thanks. I just wanted to use them to display a time in milliseconds between
two events. Since I got a bunch of these 7x5 LED matrix devices I thought
that I might try and use them. Obviously there are easier ways.