how is calculate ident in NEC1 protocol

dreambox59 · Post by **dreambox59** » Sun May 10, 2020 1:43 pm

i can find easily how is define key code but i don t understand the way of calculating id
ex: for sf8008 octagon device id is A05F or 5FA0 (reverse) in rmdu files FixedData=00 5F 00 ????
for vbox6 id is 00FA or FF05 (reverse) in rmdu files FixedData=20 FF 05 OK!!!
does the first byte (00 or 20) do something ??

Post by **The Robman** » Sun May 10, 2020 2:02 pm

It's a better idea to try and understand the codes, then use the decimal codes in RM.

The hex codes that you've found are the raw binary signal in hex format, these hex codes are not the same as the hex codes used in RM. In RM we use decimal values, and how you get the deimal values from the binary varies by protocol. Some are MSB, which means you can read the decimal directly from the binary, but most are LSB which means you have the read the binary backwards (ie, left to right).

the following spreadsheet shows how to read your binary codes:
https://www.hifi-remote.com/forums/dload ... e_id=25935

a0 5f = device code 5
00 fa = device code 0 and sub-device = 250

The first byte of fixed data for the NEC protocol is a control byte which decides things like:
* Should the second byte be the complement of the first
* Do you want an NEC1 or NEC2 signal (or even NECx1 or NECx2)
* Do you want special handling of the RECORD button, etc

So, it's best to let RM decide what should go in the fixed data.

dreambox59 · Post by **dreambox59** » Mon May 11, 2020 1:16 am

thanks mr robman

i have a look on excel calculation but something is not clear :

take octagon SF8008 exemple in rmdu file there is :
Protocol.name=NEC1
ProtocolParms=5 null null 0 0
FixedData=00 5F 00

fixed data is in hex format but how to recover real id (A05f or 5fA0) ?
with your excel board i obtain $FA o $05 but not $5f ?

what is protocolparms ? when i read my remote after download it these terms are changed !

"So, it's best to let RM decide what should go in the fixed data."

i want to create a new rmdu file for an old remote
type nec1
ID = $E17A or §875E or $5E87
can you give me the way to calculate the fixed data

BR

dreambox59 · Post by **dreambox59** » Mon May 11, 2020 7:18 am

with a lot of work i understand !!!!

the excel board is required to have the good values for device and sub device

i have made a second excel board to gives fixed data values from the values above

thanks again