Panasonic's old infrared remote protocol
An other infrared remote protocol I will explain is an older Panasic remote protocol.
The protocol is similar with the RECS-80 protocol but it use more bits than the RECS-80

protocol. For the datatransmission Panasonic uses the pulse-place modulation.

For the communication a pulse is used with a fixed length, followed by a pause wich represents
the logical state of the bit.
2048 codes are defined in this protocol, divided in 5 bits of custom code and 6 bits of data
code. The custom code is a value wich represents the manufacturer code and the data code
is a value wich represents the pressed button on the remote control.
The full transmitted code is 22 bits: First a header is sent then the custom code (5 bits),

then the data code, followed by the inverse of the custom code and the invers of the data code,

and to terminate a stopbit is added to the code.
The invers transmitted bits are very usefull for the error detection.
Each first part of a bit is always a high level with a fixed time and is followed by a low level
where the time defines if the bit is a logic 1 or a logic 0.
Timing diagram:
T =420 µs to approx 424 µs in the USA and Canada
T=454 µs to approx 460 µs in Europe and others
The header is 8T high and 8T low

A 1 is coded 2T high and 6T low

A 0 is coded 2T high and 2T low
Back to homepage