[mythtv-users] How can I change channels on a Cisco HD271 DTA (with TWC)?

[Gary Buhrmaster]

On Thu, Jun 11, 2015 at 8:13 PM, Mike Perkins
<mikep at randomtraveller.org.uk> wrote:
....
> That's why the previous reply suggested an opto-isolator. Basically this is
> an LED 'blaster' and an optreceptor built into the same package for exactly
> this kind of operation where you can't be sure about electrical
> compatibility.

I prefer opto-isolators (I am a little paranoid) but one if one searches,
one can find schematics for various alternatives using single active
components.  They used to be all the rage for TiVo users back in
the day.

> Opto-isolators are basically 4- 5- or 6- pin chips which are cheap and
> (relatively) easy to find in an electronic store - or online, of course.
> Wiring up each end shouldn't be difficult if you are familiar with a
> soldering iron.

And while not the only solution, here is an example of something
that worked quite well back in the days of the Moto/Pace DTAs
(shameless self promotion follows):

https://github.com/garybuhrmaster/misc/blob/master/IR_Blaster_to_Comcast_DTA_direct_connect_cable/IR%20Blaster%20to%20Comcast%20DTA%20direct%20connect%20cable.pdf