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View Full Version : Raw Mode: FF 01 02 FF 01 02 ... What gives?



Mona
August 5th, 2005, 03:58 AM
I built a UIRT2 module to use with Linux (LIRC) and MythTV, but every time the UIRT2 is initialized it repeats FF 01 02 FF 01 02 FF 01 02 forever :x

I am using a PIC16F84-04/P at 4MHz (have tried several), RS232 cable with only GND, TXD and RXD, firmware 1.7 (tried 1.8 also - same result). The receiver line (RB3) and Input1 (RB0) have a 10K pulldown as I am not using a receiver (only need to xmit). Power is supplied with +5V from a HDD power cable (lotsa juice :o )

The UIRT_test program works flawlessly (ALL functions) unless I press the SetmodeRaw button, then I get a response of: 21 08 FF FF FF FF FF 14 01 and then FF 01 02 FF 01 02 FF 01 02 ...

I have also tried pulling RB3 and RB0 to +5V instead of GND - same results! I read the posts where replacing the PIC/receiver, checking for shorts, opens, etc. have fixed this problem, but not this time. I'm in the process of reverse-engineering the PIC code to look for bugs (and rewriting parts of LIRC to avoid sending the SetmodeRaw function) but would like something other than a Band-Aid.

Any suggestions?

Mona

Mona
October 21st, 2005, 02:29 AM
I built a UIRT2 module to use with Linux (LIRC) and MythTV, but every time the UIRT2 is initialized it repeats FF 01 02 FF 01 02 FF 01 02 forever :x

The UIRT_test program works flawlessly (ALL functions) unless I press the SetmodeRaw button, then I get a response of: 21 08 FF FF FF FF FF 14 01 and then FF 01 02 FF 01 02 FF 01 02 ...


RB3 should be pulled UP to 5V if no IR receiver is connected. The 01 02 FF is the RAW mode equivalent of a continuous IR pulse. I tried changing the pulldown resistors on RB0/ RB3 to pullups, but a solder short kept them down :oops:

21 = CMDOK (RAW mode set)
08 FF FF FF FF FF = response from receiving pulse on INPUT line (GPIO)
01 02 FF = RAW response to shorted IR receive line

Now if I could just get LIRC to actually send data...

Mona