SimonTHK
Member
Hello Electro Tech Online forum supporters
I want to have 4 x 7 segment displays in a project. Since I am using a quite big Uc I can easily get 11 output pins for this and might aswell do when I have the ports.
My idea:
First I have to pull these displays to ground (the 7 legs), I think thats called "common anode" displays. I should be able to do this by turning off my pins on my uc. I never did this, so can anyone confirm if that is a normal way to pull something to ground at an input pin on a uc=?
Also my displays need 10v but my uc can only give 5v. So if I add 10v one side and 5v (if the display is meant to be turned off) at the other side, will it blend? or will I have 5v running through the display and some current aswell? In theory it should, but I dunno if a uc can have current running through it backwards when used as an output?
7 of the pins works at output to the displays, so the displays all use the same 7 pins. I then want to turn on 1 display at a time using 4 outputs and 4 transistors.
Can anyone confirm my idea? Correct my mistakes.
I want to have 4 x 7 segment displays in a project. Since I am using a quite big Uc I can easily get 11 output pins for this and might aswell do when I have the ports.
My idea:
First I have to pull these displays to ground (the 7 legs), I think thats called "common anode" displays. I should be able to do this by turning off my pins on my uc. I never did this, so can anyone confirm if that is a normal way to pull something to ground at an input pin on a uc=?
Also my displays need 10v but my uc can only give 5v. So if I add 10v one side and 5v (if the display is meant to be turned off) at the other side, will it blend? or will I have 5v running through the display and some current aswell? In theory it should, but I dunno if a uc can have current running through it backwards when used as an output?
7 of the pins works at output to the displays, so the displays all use the same 7 pins. I then want to turn on 1 display at a time using 4 outputs and 4 transistors.
Can anyone confirm my idea? Correct my mistakes.