About 74HC595 shift register. facing problem with that.

[ikelectro]

I want to shift left to right in 74HC595. is it possible to that. if yes then how??????

 

[Roff]

What do you mean by "shift left to right"? You can shift from the serial input toward the Qh output. If you mean that you want to shift in the other direction,the answer is, you can't.
See 74HC299.

 

[ghostman11]

but cant you make it appear that way??? i have a vauge memory of being able to shift data in then output it. i dont have time to look at the sheet but i think its the enable pin is held high or maybe low?? then when you have the data ready you toggle it. so if thats the case you could shift data in any direction you want. sorry if i am wrong but i havnt messed with theese for a while
regards jason

 

[ikelectro]

but cant you make it appear that way??? i have a vauge memory of being able to shift data in then output it. i dont have time to look at the sheet but i think its the enable pin is held high or maybe low?? then when you have the data ready you toggle it. so if thats the case you could shift data in any direction you want. sorry if i am wrong but i havnt messed with theese for a while
regards jason

if you provide some more information, it'll be more helpful!!!!
I'll try it, what you said.!!!!!!!!

 

[ghostman11]

the way i see it you have a latch on the shift, so the pins dont see the data untill you latch it in. so shift the data right to left then latch, if you do it one bit at a time then i think it will appear to do what you want. if i get some time later i will try and have a look at it, maybe someone else can explain it better than i can

 

[ikelectro]

the way i see it you have a latch on the shift, so the pins dont see the data untill you latch it in. so shift the data right to left then latch, if you do it one bit at a time then i think it will appear to do what you want. if i get some time later i will try and have a look at it, maybe someone else can explain it better than i can

you are most welcomed.
I,ll be happy if you look into this.....thanks....

 

[ikelectro]

ok, I'll try what you said.........

 

[Roff]

the way i see it you have a latch on the shift, so the pins dont see the data untill you latch it in. so shift the data right to left then latch, if you do it one bit at a time then i think it will appear to do what you want. if i get some time later i will try and have a look at it, maybe someone else can explain it better than i can

How do you select the shift direction? Once you have data in the shift register, it can only flow one way.
As I said, you might be able to use 74HC299. It is a universal, shift-left, shift-right shift register.

 

[Blueteeth]

Whether a shift register shifts 'left or right', is kind of meaningless. You have an input, and 8 registers, the 595 has an 8-bit storage latch too. There is nothing to say you can't make D0 your MSB, and D7 your LSB.

That chip first loads in the serial input into stage 0, then after 7 more clocks, that bit is now in stage 7 - so in terms of using it to read SPI, or serial data, it is MSB-first. (first bit sent,ends up on D7, last ends up on D0). Providing you don't need to change direction, simply declare the stages backwards, with D0 being the new D7, and D7 being D0...

 

[ghostman11]

How do you select the shift direction? Once you have data in the shift register, it can only flow one way.
As I said, you might be able to use 74HC299. It is a universal, shift-left, shift-right shift register.

i think blueteeth has explained it better than me. i will attempt to try and explain a bit better but forgive me if i mess it up lol. all i was saying was you could say load the register with say the following 00000001 then latch out then load 00000010 and latch out, this is obviously moveing the output LSB-MSB or you could reverse it and load 100000000 latch out, load 01000000 latch out and this moves the output MSB-LSB. like blueteeth i dont see a problem with direction on this chip unless the latch isnt used in wich case the output changes as the data is changed. i did a project with shift registers and my mistake was not useing the latch once i found that out i was able to move data in any direction i wanted. OR i am miss understanding the OP and what he wants????? i cant find the code i used in the end as it was probally 18+ months ago,

 

[ikelectro]

ok, guys.... let see what happen. I'll work on what was said by blueteeth!!!!!!!! If I facing problem I'll post it here