opto shift register

https://www.dropbox.com/scl/fi/weo0og6siaf5ano8thng3/Opto_Shift_Reg.jpg?rlkey=g170fs3jzg6zftzrrvr3phmd4&raw=1

A short low pulse shifts a 1 and a long pulse shifts a 0.

On 2023-12-18 19:24, john larkin wrote:
> https://www.dropbox.com/scl/fi/weo0og6siaf5ano8thng3/Opto_Shift_Reg.jpg?rlkey=g170fs3jzg6zftzrrvr3phmd4&raw=1
> 
> A short low pulse shifts a 1 and a long pulse shifts a 0.

The idea has been used in an Electronics Design Idea: an even longer pulse was used to gate the output latch.
It was used to drive an LCD display (HD44780) using one line only.

Arie

On 12/18/23 10:24, john larkin wrote:
> https://www.dropbox.com/scl/fi/weo0og6siaf5ano8thng3/Opto_Shift_Reg.jpg?rlkey=g170fs3jzg6zftzrrvr3phmd4&raw=1
> 
> A short low pulse shifts a 1 and a long pulse shifts a 0.
> 
Well,that's cute, but not useful without some guaranteed resting high 
time for the pulse train. If the cap doesn't recharge fully between low 
intervals, it gets indeterminate as to what happens.

On Mon, 18 Dec 2023 12:49:59 -0800, wmartin <wwm@wwmartin.net> wrote:

>On 12/18/23 10:24, john larkin wrote:
>> https://www.dropbox.com/scl/fi/weo0og6siaf5ano8thng3/Opto_Shift_Reg.jpg?rlkey=g170fs3jzg6zftzrrvr3phmd4&raw=1
>> 
>> A short low pulse shifts a 1 and a long pulse shifts a 0.
>> 
>Well,that's cute, but not useful without some guaranteed resting high 
>time for the pulse train. If the cap doesn't recharge fully between low 
>intervals, it gets indeterminate as to what happens.

Sure, but I'll control the drive waveform.

I want a bunch of pretty slow isolated control signals, and
multi-channel digital isolators are big and expensive.

mandag den 18. december 2023 kl. 19.24.58 UTC+1 skrev john larkin:
> https://www.dropbox.com/scl/fi/weo0og6siaf5ano8thng3/Opto_Shift_Reg.jpg?rlkey=g170fs3jzg6zftzrrvr3phmd4&raw=1 
> 
> A short low pulse shifts a 1 and a long pulse shifts a 0.

sorta similar to these LED drivers, https://www.tme.eu/dk/en/details/ws2811-m/led-drivers/worldsemi/ws2811-msop8/

On Mon, 18 Dec 2023 16:40:42 -0800 (PST), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

>mandag den 18. december 2023 kl. 19.24.58 UTC+1 skrev john larkin:
>> https://www.dropbox.com/scl/fi/weo0og6siaf5ano8thng3/Opto_Shift_Reg.jpg?rlkey=g170fs3jzg6zftzrrvr3phmd4&raw=1 
>> 
>> A short low pulse shifts a 1 and a long pulse shifts a 0.
>
>sorta similar to these LED drivers, https://www.tme.eu/dk/en/details/ws2811-m/led-drivers/worldsemi/ws2811-msop8/

That is an impressively bad data sheet.

tirsdag den 19. december 2023 kl. 02.24.54 UTC+1 skrev John Larkin:
> On Mon, 18 Dec 2023 16:40:42 -0800 (PST), Lasse Langwadt Christensen 
> <lang...@fonz.dk> wrote: 
> 
> >mandag den 18. december 2023 kl. 19.24.58 UTC+1 skrev john larkin: 
> >> https://www.dropbox.com/scl/fi/weo0og6siaf5ano8thng3/Opto_Shift_Reg.jpg?rlkey=g170fs3jzg6zftzrrvr3phmd4&raw=1 
> >> 
> >> A short low pulse shifts a 1 and a long pulse shifts a 0. 
> > 
> >sorta similar to these LED drivers, https://www.tme.eu/dk/en/details/ws2811-m/led-drivers/worldsemi/ws2811-msop8/
> That is an impressively bad data sheet.

indeed :)

On a sunny day (Mon, 18 Dec 2023 10:24:39 -0800) it happened john larkin
<jl@650pot.com> wrote in <re31oid9dqb1136cj5rctmnruvvhrm47nl@4ax.com>:

>https://www.dropbox.com/scl/fi/weo0og6siaf5ano8thng3/Opto_Shift_Reg.jpg?rlkey=g170fs3jzg6zftzrrvr3phmd4&raw=1
>
>A short low pulse shifts a 1 and a long pulse shifts a 0.

What,s the use?

On a sunny day (Mon, 18 Dec 2023 16:40:42 -0800 (PST)) it happened Lasse
Langwadt Christensen <langwadt@fonz.dk> wrote in
<50752cee-2eb8-4219-b896-39b13284f0d9n@googlegroups.com>:

>mandag den 18. december 2023 kl. 19.24.58 UTC+1 skrev john larkin:
>> https://www.dropbox.com/scl/fi/weo0og6siaf5ano8thng3/Opto_Shift_Reg.jpg?rlkey=g170fs3jzg6zftzrrvr3phmd4&raw=1 
>> 
>> A short low pulse shifts a 1 and a long pulse shifts a 0.
>
>sorta similar to these LED drivers, https://www.tme.eu/dk/en/details/ws2811-m/led-drivers/worldsemi/ws2811-msop8/

Interesting, thanks you.

tirsdag den 19. december 2023 kl. 07.16.02 UTC+1 skrev Jan Panteltje:
> On a sunny day (Mon, 18 Dec 2023 16:40:42 -0800 (PST)) it happened Lasse 
> Langwadt Christensen <lang...@fonz.dk> wrote in 
> <50752cee-2eb8-4219...@googlegroups.com>:
> >mandag den 18. december 2023 kl. 19.24.58 UTC+1 skrev john larkin: 
> >> https://www.dropbox.com/scl/fi/weo0og6siaf5ano8thng3/Opto_Shift_Reg.jpg?rlkey=g170fs3jzg6zftzrrvr3phmd4&raw=1 
> >> 
> >> A short low pulse shifts a 1 and a long pulse shifts a 0. 
> > 
> >sorta similar to these LED drivers, https://www.tme.eu/dk/en/details/ws2811-m/led-drivers/worldsemi/ws2811-msop8/
> Interesting, thanks you.

it is the same or similar IC build into an RGB led that is in those cheap individually addressable LED strips

https://www.aliexpress.com/item/4001322411818.html