Onkyo DX-701 CD Player
I own that 20 years old CD Player, it still sounds very good :
At the back of the player you find the RI port (Remote Interactive). It is a 3.5mm mono jack that can be used to connect other Onkyo elements :
For example if you connect an Onkyo amplifier with an IR remote, the amplifier IR remote can control both the amplifier and the player thanks to the Remote Interactive port. In fact you can daisy chain several onkyo elements (Tape player, DVD player, etc.) and control all the elements with a single remote.
This is a very clever idea and today all Onkyo HIFI elements still sport a Remote Interactive port.
Onkyo RI protocol
The LIRC project provides information about the RI protocol :
The files give the pulses encoding under LIRC format is as follows (durations are in µseconds) :
bits 12 flags SPACE_ENC|CONST_LENGTH eps 30 aeps 100 header 3000 1000 one 1000 2000 zero 1000 1000 ptrail 1000 gap 67000 toggle_bit 0
- From there it is very easy to draw the form of the signal. It is space encoded, with a header and a trailer and the message is composed of 12 bits :
Now we know the waveform and the encoding of the Remote Interactive signal, what about the signal level ?
Given the age of the CD Player (and of the RI protocol) the signal is TTL, that is :
- 0 (low) is 0 Volt
- 1 (high) is 5 Volts
For more details about TTL you may refer to Wikipedia
RI Codes for DX-701
The codes for my DX-701 CD Player cover all the functionalities that are accessible on the device facade :
# RI codes for DX-701 CD Player # RI codes for DX-701 CD Player CD_Forward 0x0F00 CD_Rewind 0x0F01 CD_Repeat 0x0F06 CD_Clear 0x0F08 CD_Memory 0x0F09 CD_Display 0x0F0A CD_Eject 0x0F0B CD_8 0x0F0C CD_9 0x0F0D CD_0 0x0F0E CD_Digits 0x0F0F CD_1 0x0F10 CD_2 0x0F11 CD_3 0x0F12 CD_4 0x0F13 CD_5 0x0F18 CD_6 0x0F19 CD_7 0x0F1A CD_Play 0x0F1B CD_Stop 0x0F1C CD_Next 0x0F1D CD_Prev 0x0F1E CD_Pause 0x0F1F CD_Random 0x0F46
A rather complete list of Remote Interactive commands is given on the LIRC project site.