LDmicro Forum - please help

please help (by hassan)

how can use ladder communication with 8-bit parallel-in/serial out shift register 74HC165

Thu Dec 22 2016, 15:41:07

please help (by hassan)

or 8-bit static shift register HEF4021B

Thu Dec 22 2016, 15:47:29

(no subject) (by MGP)

I can not understand why you want to make something like this, I can't see the point of it.

Presenting 8 bits to a shift register by a controller and then let the controller shift the same 8 bits out from that shift register IC, a crazy idea if you ask me. ;)

Look here what I want to say:

http://cq.cx/ladder-forum.pl?action=viewthread&parent=2461

Thu Dec 22 2016, 17:22:24

(no subject) (by hassan)

Thank you for attention
I used hef4094 to get a large number output microcontrollers
I want to use 74hc165 for a large number input microcontrollers

Thu Dec 22 2016, 21:32:15, download attachment 74HC165-register-circuit.png

(no subject) (by hassan)

Parallel to Serial Shifting-In with a CD4021BE

Thu Dec 22 2016, 21:39:00, download attachment CD4021.png

(no subject) (by MGP)

I still think it's a bad idea.
It takes minimum 16 cycletimes for 1 cycle, you can't use OSR/OSF, you can't use timers on the inputs.
You have to wait at least 16 cycletimes before you can use the input values.
As for me LDmicro is too slow for this.

I suggest to take a controller with more IO.

It is also a good excercise to make a program on your own because you have to incorporate it in your program and it's better that you fully understand how it works.

1 load output, A 8 counter, 8 variables.

Fri Dec 23 2016, 00:44:56