This document covers the old white apple remote.
- Carrier: ~38KHz
- Start: 9ms high, 4.5ms low
- Pulse width: ~0.58ms (~853Hz)
Uses pulse-distance modulation.
Bit encoding:
- 0: 1 pulse-width high, 1 pulse-width low
- 1: 1 pulse-width high, 3 pulse-widths low
4 octets are transmitted, LSB first.
First two octets in normal transmission are 0x77 0xE1. (Different for pair command, which is 0x07 0xE1) Third octet is command. Fourth octet is remote ID.
One of these bits is used for the low-battery indication. I haven't yet identified which one.
Example codes (in transmission order):
01110111 11100001 01000000 11101011 MENU
01110111 11100001 10110000 11101011 VOL-
01110111 11100001 11010000 11101011 VOL+
01110111 11100001 00100000 11101011 PLAY
01110111 11100001 11100000 11101011 NEXT
01110111 11100001 00010000 11101011 PREV
01110111 11100001 01101000 11101011 ??? (MENU+VOLUP)
00000111 11100001 11000000 11101011 PAIR (MENU+NEXT)Normal Command format: 000XXXXP, where XXXX is the command and P is a parity bit(even parity).
Commands (MSB First):
0x01: 000 0001 0 MENU
0x02: 000 0010 0 PLAY
0x03: 000 0011 1 NEXT
0x04: 000 0100 0 PREV
0x05: 000 0101 1 VOL+
0x06: 000 0110 1 VOL-
0x0B: 000 1011 0 ???? (MENU+VOLUP)
0x0C: 000 1100 1 ???? (MENU+VOLDOWN)Special Commands:
- MENU+NEXT : Pair
- MENU+PLAY : Increment Remote Code
- MENU+PREV : ???
As far as I can tell, there are 8 normal signals that the remote can emit, and 3 special signals---for a total of 11 signals.
01110111 11100001 00100000 01010000 PLAY
00000111 11100001 11000000 01010000 PAIR
00000111 11100001 10100000 01010000 ??? (MENU+PREV)
00000111 11100001 01000000 11010000 CHANGE CODE (MENU+PLAY)
01110111 11100001 10011000 00110000 ??? (MENU+VOLDOWN)