S-Link 40khz IR Demodulator
Why and what is this?
This project adds an IR 40Khz demodulator that attaches to the S-Link port
on my STR-DA90ESG amp. This allows any programmed remote to send normal
40Khz signals across the room and control most basic functions of the amp.
Because this is a standard IR signal, any learning remote can learn these codes
from a correctly programmed transmitter.
This external device does not require that you modify your Sony product in any
way, or require a second Sony product to attach to.
Why do this? Because the VisionTouch units (model numbers ending in G) use
a 455Khz IR remote. There is no learning remote, or pre-programmed remote
on the market today (end of 1999) that can control the VisionTouch units
directly (including ones made by Sony).
The Philips Pronto can
send 455Khz commands, but can not learn them. To date there is no VisionTouch
CCF to solve this problem (I'm working on one).
How it works:
This is not a basic primer on IR functionality. Sony S-Link uses a simple repeatable
binary command code (no parity). This code has 5 or more bits depending on the
age of the command (current commands have 20 or more bits). Sony first started
using this simple command in two forms, 40Khz modulated IR signals and
direct TTL signals on the Control-S ports. Sony later used two protocols,
one for IR commands and one for TTL bus commands (Control-S/Control-A/S-Link).
This IR demodulator just converts binary S-Link commands sent by the remote
into TTL signals injected into the S-Link bus. The Sony amp just thinks there
is a device (like a DVD player) sending commands to it...like, power on please
and select DVD video input while you are at it...Because newer components
were not meant to be user controlled from a remote by the S-Link port most of
the commands are discrete. For example there is 'power on' and 'power off'
as separate commands, but no simple 'power' command (to turn on or off the unit)
...or at least I have not found them yet....(see commands section)
Stuff you need:
Parts from Radio Shack, or just sitting around the house:
- 276-137 $3.59 40Khz IR demodulator
- 273-1757 $13.99 4.5V AC-DC power adapter (regulated and filtered)
- 273-1716 $1.99 adaptor plug 5.5mm/2.1mm (free with above power adapter)
- 270-288 $1.99 small black plastic case
- 274-1563 $1.69 power jack 5.5mm/2.1mm
- 274-246 $1.49 1/8" stereo jack
- 42-2387 $3.99 1/8" to 1/8" stereo patch cable
- some wire (22ga)
Cost about $23 to $27 depending on if you need the patch cable. (I used an
18" one I had siting around)
The power adapter should be 5V, but the 4.5V version works ok. It does need
to be regulated AND filtered, remember you are ataching this to an expensive
item! Regulation is required so the TTL signal is the correct voltage and
filtering keeps the signal clean so your equipment is not confused.
Tools you need:
- Soldering iron
- solder
- drill
- drill bits
- #1 phillips screwdriver
- wire cutters/strippers
- black pen (sharpe)
Construction:
Pronto Programming information:
- My whole CCF file (including my other devices)
- My STR-DA90ESG 40Khz S-Link IR DB device file