Hi everyone,
I am building transistor switches using multiple 74hc595. However I need to change pin values quicker that the whole shifting process, so I decided to split the whole bus into two, fast(always changing) and slow. My question is can I set the data and clock connection to be common for the two buses or I have to have six connections.
braev:
Hi everyone,I am building transistor switches using multiple 74hc595. However I need to change pin values quicker that the whole shifting process, so I decided to split the whole bus into two, fast(always changing) and slow. My question is can I set the data and clock connection to be common for the two buses or I have to have six connections.
Doesn't make sense.
Two busses could be slower, because everything in an Arduino happens after each other, not at the same time.
If you want to shift out a lot faster, then use SPI instead of shiftout().
Leo..
Wawa:
Doesn't make sense.
Two busses could be slower, because everything in an Arduino happens after each other, not at the same time.
If you want to shift out a lot faster, then use SPI instead of shiftout().
Leo..
My idea was to constantly change the fast bus, because the other doesn't need that much speed. But combined they are slower than what I need. Anyways can I connect the clock and data pins(but two different latch pins) of the two together, without affecting the work of them both.
Yes, I think so.
You can clock anything you want in a string of shift registers.
It stays inside until the latchpin goes high.
Leo..
Wawa:
Yes, I think so.
You can clock anything you want in a string of shift registers.
It stays inside until the latchpin goes high.
Leo..
Thanks, I will try it.
If you use the same clock and data pins the two shift registers will run at the same speed and be sent the same data.
braev:
My idea was to constantly change the fast bus, because the other doesn't need that much speed. But combined they are slower than what I need. Anyways can I connect the clock and data pins(but two different latch pins) of the two together, without affecting the work of them both.
You can do that, but think about this:
You say that updating both busses at the same time is too slow, you need more speed for your "fast bus".
You may get around that limitation by updating the "fast bus" on its own, but whenever you update the "slow bus", you will be too slow again - at least for that update cycle.
If that is acceptable for you, then you can go ahead.