#36 Partial key abnormal in RC6 type

[Jason Chou]

Hi Sirs,

We're trying to make IR transmitter by self. Right now NEC type all works but partial RC6 key still abnormal.
Abnormal key as following. (sent key by Winlirc-0.9.0i)
sent key receiver got
num2 (0x00100010) 3 (0x00100011)
4 (0x00100100) 7 (0x00100111)
8 (0x00101000) f (0x00101111)
5 (0x00100101) fail to receive any IR key

It looks like abnormal key has some rule ?
Could someone help to identify possible problem ? We've debug so long ...
Thanks for great help in advance.
Here is our config. for reference.

begin remote

name Philips_RC6
bits 8
flags RC6|CONST_LENGTH
eps 30
aeps 100

header 2667 889
one 444 444
zero 444 444
pre_data_bits 13
pre_data 0x0FFF
gap 108000
min_repeat 2
toggle_bit 5
frequency 36000

  begin codes
        NUMERIC_1    0x001000fe 
        NUMERIC_2    0x001000fd 
        NUMERIC_3    0x001000fc 
        NUMERIC_4    0x001000fb 
        NUMERIC_5    0x001000fa 
        NUMERIC_6    0x001000f9 
        NUMERIC_7    0x001000f8 
        NUMERIC_8    0x001000f7 
        NUMERIC_9    0x001000f6 
        NUMERIC_0    0x001000ff

[Ian]

Have you tried using raw codes?

[Jason Chou]

Dear Ian,

Thanks for quickly reply.
May I ask what “raw codes” mean ? Do you’ve sample code or URL for this methodology introduce ?
Thanks a lot.

[Ian]

Not all remote control protocols can be successfully decoded. In these cases you can capture raw codes from the remote. Which is simply the raw pulse/space information. These can be replayed later. It's pretty simple. It can trip up with toggle bits for button repeats, but that's not the end of the world.

In irrecord you want to use the -f command line
That will prevent it from trying to decode the protocol

[Jason Chou]

We found some symptom in receiver part.
Correct key bandwith are fixed in 440 ms, but fail key bandwidth 440 at beginning but around 520 ms in the middle and 300 ms in the finally ? It looks like floating in bandwith ...
Is it related that we use FTDI chip/driver as UART transfer ? Many thanks.

[Jason Chou]

Besides, if I would like to rebuild winlirc's serial.dll for able to output higher baud rate(>256000).
Where should I add ? I tried to add in source code DLL\IRMan(or IRToy)serial.h and winbase.h then rebuild.
ex:
EBaud256000 = CBR_256000, // 256000 bits/sec
EBaud380400 = CBR_380400, // 380400 bits/sec
EBaud460800 = CBR_460800, // 460800 bits/sec
EBaud921600 = CBR_921600, // 921600 bits/sec

But higher baud rate didn't show up for user select after loaded plugin: serial.dll.
Many thanks.

[Ian]

Which plugin are you actually using? You'll probably find that real supports don't support rates higher than 115200. That has been my experience anyway.

[Jason Chou]

We're used SerialDevice.dll and found more higher baud rate(>=115200) has 10% success rate.
So we're plan to add higher baud rate and rebuild this plugin but fail.(rebuild success but high baud rate won't show up in tool list)
Default max. is 256000 and would like up to 921600 to see the result.
Or our RC6 4 key abnormal problem is NOT here ? Thanks.

Attachment shows:
Correct key bandwith are fixed in 440 ms, but fail key bandwidth 440 at beginning but around 520 ms in the middle and 300 ms in the finally. It looks like floating in bandwith ...

[Ian]

Are you using a serial card? Because motherboard serial ports definitely don't support those kind of speeds

[Jason Chou]

We use com port thru. a kit board. The kit board within a FTDI (USB/UART FIFO IC) that generates 2 available com port, would it be an issue ?
But we use the kit board to collect log by change baud rate(57600, 115200 ... etc) seems works normally in usual. Thanks a lot.

[Ian]

USB -> serial the latency is really bad. It can't be used with the serial.dll plugin. If you are using a desktop PC, a lot of motherboards still have real serial ports, you just need to buy a header to attach to the them. Failing that try a PCI serial port card.