Synchronizing multiple 28X

[Andres Rodriguez]

I am building a sign with 6 LED arrays. The arrays are 5x7. I wrote the code to represent the entire alphabet (one letter per array). To do that I’m using 7 of the output pins (28X) and five of the pins on Port C as outputs. I don’t mind using one 28X on each array but I need help synchronizing them so the code running on each chip executes at the right time.

 

[andrew_qld]

Do you need the chips to all do something at the same time or in sequence? (eg chip1 finishes doing something then triggers chip2).

If all at the same time, you could use a spare input on each chip so the code all starts at the same time.

If you are sequencing them then you could use one output pin on the first 28X to go high (or low) which is then tied to an input on the next 28x etc.

Whichever way you decide to go (high or low) you should tie the leg to +v or ground through a resistor so it doesn't "float".

 

[Andres Rodriguez]

Thankyou Andrew

I'll test it tomorrow in the breadboard. By the way, the sign is for my grandson's birthday and it will say his name, then it will go blank and say IS TWO. Coincindentally, his name is ANDREW.
Thank you for your help.
Andres
(also coincidentally, but my name is spelled in Spanish )