Up-Down Counter using ICM7217

Thread Starter


Joined Sep 12, 2018
this is my first post in this splendid forum.
...and yes, I have read the rules, but, sorry, I need a little help from you.

I need a 6 digit 7-segment led display, up-down counter with leading zeroes blanking,
and because I don't know other compact solution or how to program a microcontroller,
I choose to use the ICM7217
ICM7217 Datasheet

At least 6 digits and Blanking leading zeroes are the foundamental requisites.

I decided to use the example printed in the ICM7217 datasheet fig.22 at page 28,
but I don't know if is best to use common anode as suggested or a common cathode:
could someone tell me the pratical differences in terms of functionality?

An other question, the most important, about the schematic (always fig 22) in the datasheet:
I did not understand if, how, and where, connect pins 4-7 of both 7217
and and how and where to connect exactly the pins 15 to 19 and 21 and 22 of the High Order 7217
(the one on the left)

Last question is about the 4 digit led display:
not much for aesthetic reasons, but more for necessity, I would prefer to use a blue display,
but, reading the datasheet, it seems to me that the voltage that drives the segments and the
forward current are not enough for a blue display with a character height of of 0,56 inc / 14.2 mm

Please, could someone help me and teach me about these details?

Kind regards