7seg Displays - common cathode

Moderator: Benj

Post Reply
medelec35
Matrix Staff
Posts: 9520
Joined: Sat May 05, 2007 2:27 pm
Location: Northamptonshire, UK
Has thanked: 2585 times
Been thanked: 3815 times
Contact:

7seg Displays - common cathode

Post by medelec35 »

When controlling common cathode 7seg displays with a microcontroller, each cathode is normally connected to a collector of an NPN transistor.
For the 7seg to be enabled the O/P pin has to go high, as transistor inverts the signal.
Currently the outputs to common are only low to enable the 7ssg.
Is it possible to have a choice for the common output to be either high or low?
Martin

User avatar
Benj
Matrix Staff
Posts: 15312
Joined: Mon Oct 16, 2006 10:48 am
Location: Matrix TS Ltd
Has thanked: 4803 times
Been thanked: 4314 times
Contact:

Re: 7seg Displays - common cathode

Post by Benj »

Thanks Martin,

Good suggestion there, I've made the change to the single and quad components and I'll get this pushed to the update system for you tonight.

medelec35
Matrix Staff
Posts: 9520
Joined: Sat May 05, 2007 2:27 pm
Location: Northamptonshire, UK
Has thanked: 2585 times
Been thanked: 3815 times
Contact:

Re: 7seg Displays - common cathode

Post by medelec35 »

Thanks Ben,
That was causing an issue here.
Martin

User avatar
Benj
Matrix Staff
Posts: 15312
Joined: Mon Oct 16, 2006 10:48 am
Location: Matrix TS Ltd
Has thanked: 4803 times
Been thanked: 4314 times
Contact:

Re: 7seg Displays - common cathode

Post by Benj »

Should be there now :D

Post Reply