I am building a 24x6 LED matrix following this guide
But I want to modify the code. In order to modify the code, I need to be able to reference specific LEDs in the matrix to turn on, rather than having it create letters that are 6 lights wide. How does referencing LEDs to turn on and off work?
you can lite any led on the array, but you need to how a shift register works, are you there yet?
I'm pretty sure I understand how they work. If you have a shift register that holds 4 numbers, you input a number which goes into slot 1, and on the next clock cycle that number is pushed to slot 2 and a new number is pushed to slot 1, and so on.
I understand how this can be used to reference LEDs, I just have no Arduino coding knowledge so I don't know how to do this.
master565:
I'm pretty sure I understand how they work.
No that is not right a shift register uses bit patterns that are transferred to it's output pins. One shift register holds one bit pattern which can be stored as one number in a byte or char type variable.
Instructables are normally crap do not pay attention to them.
Have a read of this:-
http://www.thebox.myzen.co.uk/Workshop/LED_Matrix.html
Have a read of this:-
http://www.thebox.myzen.co.uk/Workshop/LED_Matrix.html
I understand how it works when you use a different pin to address different rows and columns, but I need to do this with only two pins using shift registers as shown in the instructables link. I don't have a choice in the hardware, so how I build this isn't up for discussion, but I do need to write the software for the project, and that page doesn't explain how to do it with shift registers.
I don't have a choice in the hardware, so how I build this isn't up for discussion,
No but without posting the schematic than no one can tell if you have the code right.
Still if you don't want help that is up to you, but why are you posting here in that case?