LightwaveRF RF Protocol

The LightwaveRF RF protocol operates over 433.92MHz using on-off keying (OOK).

Data

The data consists of 5 bytes / 10 nibbles. They are as follows:

Nibbles 1 and 2: a parameter for the commands. This might be the dim level or various other things
Nibble 3: ""subunit"" - some remotes support individually controlling up to 16 devices. A nibble can have 16 values. Coincidence? ;)
Nibble 4: ""command"" - the command, e.g. OFF, ON, SET_LEVEL.
Nibbles 5-10: ""ID" the identifier of the remote, used with the subunit in pairing

Payload encoding

Each nibble of data is encoded as one of 16 bytes, from the table below:

Nibble value	Byte bits	Byte hex
0x0	1111 0110	0xF6
0x1	1110 1110	0xEE
0x2	1110 1101	0xED
0x3	1110 1011	0xEB
0x4	1101 1110	0xDE
0x5	1101 1101	0xDD
0x6	1101 1011	0xDB
0x7	1011 1110	0xBE
0x8	1011 1101	0xBD
0x9	1011 1011	0xBB
0xA	1011 0111	0xB7
0xB	0111 1110	0x7E
0xC	0111 1101	0x7D
0xD	0111 1011	0x7B
0xE	0111 0111	0x77
0xF	0110 1111	0x6F

The payload is constructed from these nibbles in the following way:

payload = "1"
for each nibble
  payload += "1"
  payload += lookup[nibble]
payload += "1"

E.g. to send the ON command (0x1) with no parameter (0x00) from remote 0xFEFEFE subunit 0xF, we'd have the following nibbles:

	Parameter		Subunit	Command	ID
Nibbles	0x0	0x0	0xF	0x1	0xF	0xE	0xF	0xE	0xF	0xE
Encoded	1111 0110	1111 0110	0110 1111	1110 1110	0110 1111	0111 0111	0110 1111	0111 0111	0110 1111	0111 0111

Thus producing:

1  1  1111 0110  1  1111 0110  1  0110 1111  1  1110 1110  1  0110 1111  
   1  0111 0111  1  0110 1111  1  0111 0111  1  0110 1111  1  0111 0111  1

RF signal

The RF signal is generated from this in the following way:

for each bit, index in payload when bit is 1
  send high for 250μs
  if payload[index+1] is 0
    send low for 1250μs
  else
    send low for 250μs

In other words the sequence "10" is encoded as a 250μs high followed by a 1250μs low, whereas the sequence "1" is sent as a 250μs high followed by a 250μs low. Note: the encoding never allows for two zero bits to touch.

Commands

Observed from (siemens JSJSLW100LBK) remote

Command	Hex parameter	meaning
ON	x00	On (to last level)
	xBF	increase brightness
OFF	x00	Turn off (sometimes followed by x40)
	xA0	decrease brightness
	xC0	All off, sent with subunit D4
MOOD	x82	set lights to mood (mood #2?)
	x02	Set current level to mood memory (mood #2 ?)

Observed behaviour

Command	Hex parameter	meaning
ON	x00 - x3F	On (to last level)
	x40 - x5F x60 - x7F x80 - x9F	set specific level (out of 32 levels)
	xA0 - xBF	increase brightness
	xC0 - xDF xE0 - xEF	set all to specific level (out of 32 levels)
OFF	x00 - x7F	Turn off
	x80 - X9F	set specific level (out of 32 levels) if already on
	xA0 - xBF	decrease brightness
	xC0 - xEF	all off

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